Symbiosis

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Symbiosis 

In a cleaning symbiosis, the clownfish feeds on small invertebrates that otherwise have potential to harm the sea anemone, and the fecal matter from the clownfish provides nutrients to the sea anemone. The clownfish is protected from predators by the anemone's stinging cells, to which the clownfish is immune. The clownfish emits a high pitched sound that deters butterfly fish, which would otherwise eat the anemone, making the relationship mutualistic.

Symbiosis (from Greek συμβίωσις, sumbíōsis, "living together", from σύν, sún, "together", and βίωσις, bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasitic. The organisms, each termed a symbiont, must be of different species. In 1879, Heinrich Anton de Bary defined it as "the living together of unlike organisms". The term was subject to a century-long debate about whether it should specifically denote mutualism, as in lichens. Biologists have now abandoned that restriction.

Symbiosis can be obligatory, which means that one or more of the symbionts entirely depend on each other for survival, or facultative (optional), when they can generally live independently.

Symbiosis is also classified by physical attachment. When symbionts form a single body it is called conjunctive symbiosis, while all other arrangements are called disjunctive symbiosis. When one organism lives on the surface of another, such as head lice on humans, it is called ectosymbiosis; when one partner lives inside the tissues of another, such as Symbiodinium within coral, it is termed endosymbiosis.

Definition

Diagram of the six possible types of symbiotic relationship, from mutual benefit to mutual harm.

The definition of symbiosis was a matter of debate for 130 years. In 1877, Albert Bernhard Frank used the term symbiosis to describe the mutualistic relationship in lichens. In 1878, the German mycologist Heinrich Anton de Bary defined it as "the living together of unlike organisms". The definition has varied among scientists, with some advocating that it should only refer to persistent mutualisms, while others thought it should apply to all persistent biological interactions (in other words, to mutualism, commensalism, and parasitism, but excluding brief interactions such as predation). In the 21st century, the latter has become the definition widely accepted by biologists.

In 1949, Edward Haskell proposed an integrative approach with a classification of "co-actions", later adopted by biologists as "interactions".

Obligate versus facultative

Relationships can be obligate, meaning that one or both of the symbionts entirely depend on each other for survival. For example, in lichens, which consist of fungal and photosynthetic symbionts, the fungal partners cannot live on their own. The algal or cyanobacterial symbionts in lichens, such as Trentepohlia, can generally live independently, and their part of the relationship is therefore described as facultative (optional).

Physical interaction

Alder tree root nodule houses endosymbiotic nitrogen-fixing bacteria.

Endosymbiosis is any symbiotic relationship in which one symbiont lives within the tissues of the other, either within the cells or extracellularly. Examples include diverse microbiomes: rhizobia, nitrogen-fixing bacteria that live in root nodules on legume roots; actinomycetes, nitrogen-fixing bacteria such as Frankia, which live in alder root nodules; single-celled algae inside reef-building corals; and bacterial endosymbionts that provide essential nutrients to about 10%–15% of insects.

Ectosymbiosis is any symbiotic relationship in which the symbiont lives on the body surface of the host, including the inner surface of the digestive tract or the ducts of exocrine glands. Examples of this include ectoparasites such as lice; commensal ectosymbionts such as the barnacles, which attach themselves to the jaw of baleen whales; and mutualist ectosymbionts such as cleaner fish.

Male-male interference competition in red deer

Competition

Competition can be defined as an interaction between organisms or species, in which the fitness of one is lowered by the presence of another. Limited supply of at least one resource (such as food, water, and territory) used by both usually facilitates this type of interaction, although the competition may also exist over other 'amenities', such as females for reproduction (in the case of male organisms of the same species).

Mutualism

Hermit crab, Calcinus laevimanus, with sea anemone.

Mutualism or interspecies reciprocal altruism is a long-term relationship between individuals of different species where both individuals benefit. Mutualistic relationships may be either obligate for both species, obligate for one but facultative for the other, or facultative for both.

Bryoliths document a mutualistic symbiosis between a hermit crab and encrusting bryozoans.

A large percentage of herbivores have mutualistic gut flora to help them digest plant matter, which is more difficult to digest than animal prey. This gut flora is made up of cellulose-digesting protozoans or bacteria living in the herbivores' intestines. Coral reefs are the result of mutualism between coral organisms and various types of algae which live inside them. Most land plants and land ecosystems rely on mutualism between the plants, which fix carbon from the air, and mycorrhyzal fungi, which help in extracting water and minerals from the ground.

An example of mutualism is the relationship between the ocellaris clownfish that dwell among the tentacles of Ritteri sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators. A special mucus on the clownfish protects it from the stinging tentacles.

A further example is the goby, a fish which sometimes lives together with a shrimp. The shrimp digs and cleans up a burrow in the sand in which both the shrimp and the goby fish live. The shrimp is almost blind, leaving it vulnerable to predators when outside its burrow. In case of danger, the goby touches the shrimp with its tail to warn it. When that happens both the shrimp and goby quickly retreat into the burrow. Different species of gobies (Elacatinus spp.) also clean up ectoparasites in other fish, possibly another kind of mutualism.

A non-obligate symbiosis is seen in encrusting bryozoans and hermit crabs. The bryozoan colony (Acanthodesia commensale) develops a cirumrotatory growth and offers the crab (Pseudopagurus granulimanus) a helicospiral-tubular extension of its living chamber that initially was situated within a gastropod shell.

Many types of tropical and sub-tropical ants have evolved very complex relationships with certain tree species.

Endosymbiosis

In endosymbiosis, the host cell lacks some of the nutrients which the endosymbiont provides. As a result, the host favors endosymbiont's growth processes within itself by producing some specialized cells. These cells affect the genetic composition of the host in order to regulate the increasing population of the endosymbionts and ensure that these genetic changes are passed onto the offspring via vertical transmission (heredity).

A spectacular example of obligate mutualism is the relationship between the siboglinid tube worms and symbiotic bacteria that live at hydrothermal vents and cold seeps. The worm has no digestive tract and is wholly reliant on its internal symbionts for nutrition. The bacteria oxidize either hydrogen sulfide or methane, which the host supplies to them. These worms were discovered in the late 1980s at the hydrothermal vents near the Galapagos Islands and have since been found at deep-sea hydrothermal vents and cold seeps in all of the world's oceans.

As the endosymbiont adapts to the host's lifestyle, the endosymbiont changes dramatically. There is a drastic reduction in its genome size, as many genes are lost during the process of metabolism, and DNA repair and recombination, while important genes participating in the DNA-to-RNA transcription, protein translation and DNA/RNA replication are retained. The decrease in genome size is due to loss of protein coding genes and not due to lessening of inter-genic regions or open reading frame (ORF) size. Species that are naturally evolving and contain reduced sizes of genes can be accounted for an increased number of noticeable differences between them, thereby leading to changes in their evolutionary rates. When endosymbiotic bacteria related with insects are passed on to the offspring strictly via vertical genetic transmission, intracellular bacteria go across many hurdles during the process, resulting in the decrease in effective population sizes, as compared to the free-living bacteria. The incapability of the endosymbiotic bacteria to reinstate their wild type phenotype via a recombination process is called Muller's ratchet phenomenon. Muller's ratchet phenomenon, together with less effective population sizes, leads to an accretion of deleterious mutations in the non-essential genes of the intracellular bacteria. This can be due to lack of selection mechanisms prevailing in the relatively "rich" host environment.

Commensalism

Commensal mites travelling (phoresy) on a fly (Pseudolynchia canariensis)

Commensalism describes a relationship between two living organisms where one benefits and the other is not significantly harmed or helped. It is derived from the English word commensal, used of human social interaction. It derives from a medieval Latin word meaning sharing food, formed from com- (with) and mensa (table).

Commensal relationships may involve one organism using another for transportation (phoresy) or for housing (inquilinism), or it may also involve one organism using something another created, after its death (metabiosis). Examples of metabiosis are hermit crabs using gastropod shells to protect their bodies, and spiders building their webs on plants.

Parasitism

Head (scolex) of tapeworm Taenia solium is adapted to parasitism with hooks and suckers to attach to its host.

In a parasitic relationship, the parasite benefits while the host is harmed. Parasitism takes many forms, from endoparasites that live within the host's body to ectoparasites and parasitic castrators that live on its surface and micropredators like mosquitoes that visit intermittently. Parasitism is an extremely successful mode of life; about 40% of all animal species are parasites, and the average mammal species is host to 4 nematodes, 2 cestodes, and 2 trematodes.

Mimicry

Mimicry is a form of symbiosis in which a species adopts distinct characteristics of another species to alter its relationship dynamic with the species being mimicked, to its own advantage. Among the many types of mimicry are Batesian and Müllerian, the first involving one-sided exploitation, the second providing mutual benefit. Batesian mimicry is an exploitative three-party interaction where one species, the mimic, has evolved to mimic another, the model, to deceive a third, the dupe. In terms of signalling theory, the mimic and model have evolved to send a signal; the dupe has evolved to receive it from the model. This is to the advantage of the mimic but to the detriment of both the model, whose protective signals are effectively weakened, and of the dupe, which is deprived of an edible prey. For example, a wasp is a strongly-defended model, which signals with its conspicuous black and yellow coloration that it is an unprofitable prey to predators such as birds which hunt by sight; many hoverflies are Batesian mimics of wasps, and any bird that avoids these hoverflies is a dupe. In contrast, Müllerian mimicry is mutually beneficial as all participants are both models and mimics. For example, different species of bumblebee mimic each other, with similar warning coloration in combinations of black, white, red, and yellow, and all of them benefit from the relationship. 

Amensalism

The black walnut secretes a chemical from its roots that harms neighboring plants, an example of antagonism.

Amensalism is an asymmetric interaction where one species is harmed or killed by the other, and one is unaffected by the other. There are two types of amensalism, competition and antagonism (or antibiosis). Competition is where a larger or stronger organism deprives a smaller or weaker one from a resource. Antagonism occurs when one organism is damaged or killed by another through a chemical secretion. An example of competition is a sapling growing under the shadow of a mature tree. The mature tree can rob the sapling of necessary sunlight and, if the mature tree is very large, it can take up rainwater and deplete soil nutrients. Throughout the process, the mature tree is unaffected by the sapling. Indeed, if the sapling dies, the mature tree gains nutrients from the decaying sapling. An example of antagonism is Juglans nigra (black walnut), secreting juglone, a substance which destroys many herbaceous plants within its root zone.

Amensalism is often used to describe strongly asymmetrical competitive interactions, such as between the Spanish ibex and weevils of the genus Timarcha which feed upon the same type of shrub. Whilst the presence of the weevil has almost no influence on food availability, the presence of ibex has an enormous detrimental effect on weevil numbers, as they consume significant quantities of plant matter and incidentally ingest the weevils upon it.

Cleaning symbiosis

Cleaning symbiosis is an association between individuals of two species, where one (the cleaner) removes and eats parasites and other materials from the surface of the other (the client). It is putatively mutually beneficial, but biologists have long debated whether it is mutual selfishness, or simply exploitative. Cleaning symbiosis is well known among marine fish, where some small species of cleaner fish, notably wrasses but also species in other genera, are specialised to feed almost exclusively by cleaning larger fish and other marine animals.

Co-evolution

Leafhoppers protected by meat ants

Symbiosis is increasingly recognized as an important selective force behind evolution; many species have a long history of interdependent co-evolution.

Symbiogenesis

One hypothesis for the origin of the nucleus in eukaryotes (plants, animals, fungi, and protists) is that it developed from a symbiogenesis between bacteria and archaea. It is hypothesized that the symbiosis originated when ancient archaea, similar to modern methanogenic archaea, invaded and lived within bacteria similar to modern myxobacteria, eventually forming the early nucleus. This theory is analogous to the accepted theory for the origin of eukaryotic mitochondria and chloroplasts, which are thought to have developed from a similar endosymbiotic relationship between proto-eukaryotes and aerobic bacteria. Evidence for this includes the fact that mitochondria and chloroplasts divide independently of the cell, and that these organelles have their own genome.

The biologist Lynn Margulis, famous for her work on endosymbiosis, contended that symbiosis is a major driving force behind evolution. She considered Darwin's notion of evolution, driven by competition, to be incomplete and claimed that evolution is strongly based on co-operation, interaction, and mutual dependence among organisms. According to Margulis and her son Dorion Sagan, "Life did not take over the globe by combat, but by networking."

Co-evolutionary relationships

Mycorrhizas

About 80% of vascular plants worldwide form symbiotic relationships with fungi, in particular in arbuscular mycorrhizas.

Pollination is a mutualism between flowering plants and their animal pollinators.

Pollination

A fig is pollinated by the fig wasp, Blastophaga psenes.

Flowering plants and the animals that pollinate them have co-evolved. Many plants that are pollinated by insects (in entomophily), bats, or birds (in ornithophily) have highly specialized flowers modified to promote pollination by a specific pollinator that is correspondingly adapted. The first flowering plants in the fossil record had relatively simple flowers. Adaptive speciation quickly gave rise to many diverse groups of plants, and, at the same time, corresponding speciation occurred in certain insect groups. Some groups of plants developed nectar and large sticky pollen, while insects evolved more specialized morphologies to access and collect these rich food sources. In some taxa of plants and insects, the relationship has become dependent, where the plant species can only be pollinated by one species of insect.

Pseudomyrmex ant on bull thorn acacia (Vachellia cornigera) with Beltian bodies that provide the ants with protein

Acacia ants and acacias

The acacia ant (Pseudomyrmex ferruginea) is an obligate plant ant that protects at least five species of "Acacia" (Vachellia) from preying insects and from other plants competing for sunlight, and the tree provides nourishment and shelter for the ant and its larvae.

Time management

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Time_management 

Time management is the process of planning and exercising conscious control of time spent on specific activities, especially to increase effectiveness, efficiency, and productivity. It involves a juggling act of various demands upon a person relating to work, social life, family, hobbies, personal interests, and commitments with the finiteness of time. Using time effectively gives the person "choice" on spending or managing activities at their own time and expediency. Time management may be aided by a range of skills, tools, and techniques used to manage time when accomplishing specific tasks, projects, and goals complying with a due date. Initially, time management referred to just business or work activities, but eventually, the term broadened to include personal activities as well. A time management system is a designed combination of processes, tools, techniques, and methods. Time management is usually a necessity in any project management as it determines the project completion time and scope. It is also important to understand that both technical and structural differences in time management exist due to variations in cultural concepts of time. The major themes arising from the literature on time management include the following:

• Creating an environment conducive to effectiveness (in terms of cost-benefit, quality of results, and time to complete tasks or project),
• Setting of priorities,
• The related process of reduction of time spent on non-priorities,
• Implementation of goals.

Related concepts

Time management is related to the following concepts.

• Project management: Time management can be considered to be a project management subset and is more commonly known as project planning and project scheduling. Time management has also been identified as one of the core functions identified in project management.
• Attention management relates to the management of cognitive resources, and in particular the time that humans allocate their mind (and organize the minds of their employees) to conduct some activities.
• Timeblocking is a time management strategy that specifically advocates for allocating chunks of time to dedicated tasks in order to promote deeper focus and productivity.

Organizational time management is the science of identifying, valuing and reducing time cost wastage within organizations. It identifies, reports and financially values sustainable time, wasted time and effective time within an organization and develops the business case to convert wasted time into productive time through the funding of products, services, projects or initiatives as a positive return on investment.

Cultural views of time management

Differences in the way a culture views time can affect the way their time is managed. For example, a linear time view is a way of conceiving time as flowing from one moment to the next in a linear fashion. This linear perception of time is predominant in America along with most Northern European countries, such as Germany, Switzerland, and England. People in these cultures tend to place a large value on productive time management, and tend to avoid decisions or actions that would result in wasted time. This linear view of time correlates to these cultures being more “monochronic”, or preferring to do only one thing at a time. Generally speaking, this cultural view leads to a better focus on accomplishing a singular task and hence, more productive time management.

Another cultural time view is multi-active time view. In multi-active cultures, most people feel that the more activities or tasks being done at once the better. This creates a sense of happiness. Multi-active cultures are “polychronic” or prefer to do multiple tasks at once. This multi-active time view is prominent in most Southern European countries such as Spain, Portugal, and Italy. In these cultures, the people often tend to spend time on things they deem to be more important such as placing a high importance on finishing social conversations. In business environments, they often pay little attention to how long meetings last, rather the focus is on having high quality meetings. In general, the cultural focus tends to be on synergy and creativity over efficiency.

A final cultural time view is a cyclical time view. In cyclical cultures, time is considered neither linear nor event related. Because days, months, years, seasons, and events happen in regular repetitive occurrences, time is viewed as cyclical. In this view, time is not seen as wasted because it will always come back later, hence there is an unlimited amount of it. This cyclical time view is prevalent throughout most countries in Asia, including Japan and China. It is more important in cultures with cyclical concepts of time to complete tasks correctly, therefore most people will spend more time thinking about decisions and the impact they will have, before acting on their plans. Most people in cyclical cultures tend to understand that other cultures have different perspectives of time and are cognizant of this when acting on a global stage.

Creating an effective environment

Some time-management literature stresses tasks related to the creation of an environment conducive to "real" effectiveness. These strategies include principles such as:

• "get organized" - the triage of paperwork and of tasks,
• "protecting one's time" by insulation, isolation, and delegation,
• "achievement through goal-management and through goal-focus" - motivational emphasis,
• "recovering from bad time-habits" - recovery from underlying psychological problems, e.g. procrastination.

Also, the timing of tackling tasks is important, as tasks requiring high levels of concentration and mental energy are often done at the beginning of the day when a person is more refreshed. Literature also focuses on overcoming chronic psychological issues such as procrastination.

Excessive and chronic inability to manage time effectively may result from Attention deficit hyperactivity disorder (ADHD) or attention deficit disorder (ADD). Diagnostic criteria include a sense of underachievement, difficulty getting organized, trouble getting started, trouble managing many simultaneous projects, and trouble with follow-through. Daniel Amen focuses on the prefrontal cortex which is the most recently evolved part of the brain. It manages the functions of attention span, impulse management, organization, learning from experience, and self-monitoring, among others. Some authors argue that changing the way the prefrontal cortex works is possible and offer a solution.

Setting priorities and goals

Time management strategies are often associated with the recommendation to set personal goals. The literature stresses themes such as:

• "Work in Priority Order" – set goals and prioritize,
• "Set gravitational goals" – that attract actions automatically.

These goals are recorded and may be broken down into a project, an action plan, or a simple task list. For individual tasks or for goals, an importance rating may be established, deadlines may be set, and priorities assigned. This process results in a plan with a task list, schedule, or calendar of activities. Authors may recommend a daily, weekly, monthly, or other planning periods, associated with different scope of planning or review. This is done in various ways, as follows:

ABCD analysis

A technique that has been used in business management for a long time is the categorization of large data into groups. These groups are often marked A, B, C and D—hence the name. Activities are ranked by these general criteria:

• A – Tasks that are perceived as being urgent and important,
• B – Tasks that are important but not urgent,
• C – Tasks that are unimportant but urgent,
• D – Tasks that are unimportant and not urgent.

Each group is then rank-ordered by priority. To further refine the prioritization, some individuals choose to then force-rank all "B" items as either "A" or "C". ABC analysis can incorporate more than three groups.

ABC analysis is frequently combined with Pareto analysis.

Pareto analysis

The Pareto Principle is the idea that 80% of tasks can be completed in 20% of the given time, and the remaining 20% of tasks will take up 80% of the time. This principle is used to sort tasks into two parts. According to this form of Pareto analysis it is recommended that tasks that fall into the first category be assigned a higher priority.

The 80-20 rule can also be applied to increase productivity: it is assumed that 80% of the productivity can be achieved by doing 20% of the tasks. Similarly, 80% of results can be attributed to 20% of activity. If productivity is the aim of time management, then these tasks should be prioritized higher.

The Eisenhower Method

A basic "Eisenhower box" to help evaluate urgency and importance. Items may be placed at more precise points within each quadrant.

The "Eisenhower Method" stems from a quote attributed to Dwight D. Eisenhower: "I have two kinds of problems, the urgent and the important. The urgent are not important, and the important are never urgent." Eisenhower does not claim this insight for his own, but attributes it to an (unnamed) "former college president."

Using the Eisenhower Decision Principle, tasks are evaluated using the criteria important/unimportant and urgent/not urgent, and then placed in according quadrants in an Eisenhower Matrix (also known as an "Eisenhower Box" or "Eisenhower Decision Matrix"). Tasks in the quadrants are then handled as follows.

1. Important/Urgent quadrant tasks are done immediately and personally, e.g. crises, deadlines, problems.
2. Important/Not Urgent quadrant tasks get an end date and are done personally, e.g. relationships, planning, recreation.
3. Unimportant/Urgent quadrant tasks are delegated, e.g. interruptions, meetings, activities.
4. Unimportant/Not Urgent quadrant tasks are dropped, e.g. time wasters, pleasant activities, trivia.

POSEC method

POSEC is an acronym for "Prioritize by Organizing, Streamlining, Economizing and Contributing". The method dictates a template which emphasizes an average individual's immediate sense of emotional and monetary security. It suggests that by attending to one's personal responsibilities first, an individual is better positioned to shoulder collective responsibilities.

Inherent in the acronym is a hierarchy of self-realization, which mirrors Abraham Maslow's hierarchy of needs.

1. Prioritize your time and define your life by goals.
2. Organize things you have to accomplish regularly to be successful (family and finances).
3. Streamline things you may not like to do, but must do (work and chores).
4. Economize things you should do or may even like to do, but they're not pressingly urgent (pastimes and socializing).
5. Contribute by paying attention to the few remaining things that make a difference (social obligations).

Elimination of non-priorities

Time management also covers how to eliminate tasks that do not provide value to the individual or organization.

According to the Wall Street Journal contributor Jared Sandberg, task lists "aren't the key to productivity [that] they're cracked up to be". He reports an estimated "30% of listers spend more time managing their lists than [they do] completing what's on them".

The software executive Elisabeth Hendrickson asserts that rigid adherence to task lists can create a "tyranny of the to-do list" that forces one to "waste time on unimportant activities".

Any form of stress is considered to be debilitative for learning and life; even if adaptability could be acquired, its effects are damaging. But stress is an unavoidable part of daily life, and Reinhold Niebuhr suggests it's better to face it, as if having "the serenity to accept the things one cannot change and having the courage to change the things one can."

Part of setting priorities and goals is the emotion "worry," and its function is to ignore the present to fixate on a future that never arrives, which leads to the fruitless expense of one's time and energy. It is an unnecessary cost or a false aspect that can interfere with plans due to human factors. The Eisenhower Method is a strategy used to compete with worry and dull-imperative tasks. Worry as stress is a reaction to a set of environmental factors; understanding this is not a part of the person gives the person possibilities to manage them. Athletes under a coach call this management as "putting on the game face."

Change is hard, and daily life patterns are the most deeply ingrained habits of all. To eliminate non-priorities in study time, it is suggested to divide the tasks, capture the moments, review task handling method, postpone unimportant tasks (understanding that a task's current relevancy and sense of urgency reflect the wants of the person rather than the task's importance), manage life balance (rest, sleep, leisure), and cheat leisure and nonproductive time (hearing audio taping of lectures, going through presentations of lectures when in a queue, etc.).

Certain unnecessary factors that affect time management are habits, lack of task definition (lack of clarity), over-protectiveness of the work, the guilt of not meeting objectives and subsequent avoidance of present tasks, defining tasks with higher expectations than their worth (over-qualifying), focusing on matters that have an apparent positive outlook without assessing their importance to personal needs, tasks that require support and time, sectional interests, and conflicts, etc. A habituated systematic process becomes a device that the person can use with ownership for effective time management.

Implementation of goals

A task list (also called a to-do list or "things-to-do") is a list of tasks to be completed, such as chores or steps toward completing a project. It is an inventory tool which serves as an alternative or supplement to memory.

Task lists are used in self-management, business management, project management, and software development. It may involve more than one list.

When one of the items on a task list is accomplished, the task is checked or crossed off. The traditional method is to write these on a piece of paper with a pen or pencil, usually on a note pad or clip-board. Task lists can also have the form of paper or software checklists.

Writer Julie Morgenstern suggests "do's and don'ts" of time management that include:

• Map out everything that is important, by making a task list.
• Create "an oasis of time" for one to manage.
• Say "No".
• Set priorities.
• Don't drop everything.
• Don't think a critical task will get done in one's spare time.

Numerous digital equivalents are now available, including personal information management (PIM) applications and most PDAs. There are also several web-based task list applications, many of which are free.

Task list organization

Task lists are often diarized and tiered. The simplest tiered system includes a general to-do list (or task-holding file) to record all the tasks the person needs to accomplish and a daily to-do list which is created each day by transferring tasks from the general to-do list. An alternative is to create a "not-to-do list", to avoid unnecessary tasks.

Task lists are often prioritized in the following ways.

• A daily list of things to do, numbered in the order of their importance and done in that order one at a time as daily time allows, is attributed to consultant Ivy Lee (1877–1934) as the most profitable advice received by Charles M. Schwab (1862–1939), president of the Bethlehem Steel Corporation.
• An early advocate of "ABC" prioritization was Alan Lakein, in 1973. In his system "A" items were the most important ("A-1" the most important within that group), "B" next most important, "C" least important.
• A particular method of applying the ABC method assigns "A" to tasks to be done within a day, "B" a week, and "C" a month.
• To prioritize a daily task list, one either records the tasks in the order of highest priority, or assigns them a number after they are listed ("1" for highest priority, "2" for second highest priority, etc.) which indicates in which order to execute the tasks. The latter method is generally faster, allowing the tasks to be recorded more quickly.
• Another way of prioritizing compulsory tasks (group A) is to put the most unpleasant one first. When it's done, the rest of the list feels easier. Groups B and C can benefit from the same idea, but instead of doing the first task (which is the most unpleasant) right away, it gives motivation to do other tasks from the list to avoid the first one.

A completely different approach which argues against prioritizing altogether was put forward by British author Mark Forster in his book "Do It Tomorrow and Other Secrets of Time Management". This is based on the idea of operating "closed" to-do lists, instead of the traditional "open" to-do list. He argues that the traditional never-ending to-do lists virtually guarantees that some of your work will be left undone. This approach advocates getting all your work done, every day, and if you are unable to achieve it, that helps you diagnose where you are going wrong and what needs to change.

Various writers have stressed potential difficulties with to-do lists such as the following.

• Management of the list can take over from implementing it. This could be caused by procrastination by prolonging the planning activity. This is akin to analysis paralysis. As with any activity, there's a point of diminishing returns.
• To remain flexible, a task system must allow for disaster. A company must be ready for a disaster. Even if it is a small disaster, if no one made time for this situation, it can metastasize, potentially causing damage to the company.
• To avoid getting stuck in a wasteful pattern, the task system should also include regular (monthly, semi-annual, and annual) planning and system-evaluation sessions, to weed out inefficiencies and ensure the user is headed in the direction he or she truly desires.
• If some time is not regularly spent on achieving long-range goals, the individual may get stuck in a perpetual holding pattern on short-term plans, like staying at a particular job much longer than originally planned.

Software applications

Many companies use time tracking software to track an employee's working time, billable hours, etc., e.g. law practice management software.

Many software products for time management support multiple users. They allow the person to give tasks to other users and use the software for communication.

Tasklist applications may be thought of as lightweight personal information manager or project management software.

Modern task list applications may have built-in task hierarchy (tasks are composed of subtasks which again may contain subtasks), may support multiple methods of filtering and ordering the list of tasks, and may allow one to associate arbitrarily long notes for each task.

In contrast to the concept of allowing the person to use multiple filtering methods, at least one software product additionally contains a mode where the software will attempt to dynamically determine the best tasks for any given moment.

Time management systems

Time management systems often include a time clock or web-based application used to track an employee's work hours. Time management systems give employers insights into their workforce, allowing them to see, plan and manage employees' time. Doing so allows employers to manage labor costs and increase productivity. A time management system automates processes, which eliminates paperwork and tedious tasks.

GTD (Getting Things Done)

Getting Things Done was created by David Allen. The basic idea behind this method is to finish all the small tasks immediately and a big task is to be divided into smaller tasks to start completing now. The reasoning behind this is to avoid the information overload or "brain freeze" which is likely to occur when there are hundreds of tasks. The thrust of GTD is to encourage the user to get their tasks and ideas out and on paper and organized as quickly as possible so they're easy to manage and see.

Pomodoro

Francesco Cirillo's "Pomodoro Technique" was originally conceived in the late 1980s and gradually refined until it was later defined in 1992. The technique is the namesake of a Pomodoro (Italian for tomato) shaped kitchen timer initially used by Cirillo during his time at university. The "Pomodoro" is described as the fundamental metric of time within the technique and is traditionally defined as being 30 minutes long, consisting of 25 minutes of work and 5 minutes of break time. Cirillo also recommends a longer break of 15 to 30 minutes after every four Pomodoros. Through experimentation involving various workgroups and mentoring activities, Cirillo determined the "ideal Pomodoro" to be 20–35 minutes long.

Strategy

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Strategy 

Strategy (from Greek στρατηγία stratēgia, "art of troop leader; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the "art of the general", which included several subsets of skills including military tactics, siegecraft, logistics etc., the term came into use in the 6th century C.E. in Eastern Roman terminology, and was translated into Western vernacular languages only in the 18th century. From then until the 20th century, the word "strategy" came to denote "a comprehensive way to try to pursue political ends, including the threat or actual use of force, in a dialectic of wills" in a military conflict, in which both adversaries interact.

Strategy is important because the resources available to achieve goals are usually limited. Strategy generally involves, setting goals and priorities, determining actions to achieve the goals, and mobilizing resources to execute the actions. A strategy describes how the ends (goals) will be achieved by the means (resources). Strategy can be intended or can emerge as a pattern of activity as the organization adapts to its environment or competes. It involves activities such as strategic planning and strategic thinking.

Henry Mintzberg from McGill University defined strategy as a pattern in a stream of decisions to contrast with a view of strategy as planning, while Henrik von Scheel defines the essence of strategy as the activities to deliver a unique mix of value – choosing to perform activities differently or to perform different activities than rivals. while Max McKeown (2011) argues that "strategy is about shaping the future" and is the human attempt to get to "desirable ends with available means". Dr. Vladimir Kvint defines strategy as "a system of finding, formulating, and developing a doctrine that will ensure long-term success if followed faithfully." Complexity theorists define strategy as the unfolding of the internal and external aspects of the organization that results in actions in a socio-economic context.

Components

Professor Richard P. Rumelt described strategy as a type of problem solving in 2011. He wrote that good strategy has an underlying structure he called a kernel. The kernel has three parts: 1) A diagnosis that defines or explains the nature of the challenge; 2) A guiding policy for dealing with the challenge; and 3) Coherent actions designed to carry out the guiding policy. President Kennedy illustrated these three elements of strategy in his Cuban Missile Crisis Address to the Nation of 22 October 1962:

1. Diagnosis: "This Government, as promised, has maintained the closest surveillance of the Soviet military buildup on the island of Cuba. Within the past week, unmistakable evidence has established the fact that a series of offensive missile sites are now in preparation on that imprisoned island. The purpose of these bases can be none other than to provide a nuclear strike capability against the Western Hemisphere."
2. Guiding Policy: "Our unswerving objective, therefore, must be to prevent the use of these missiles against this or any other country, and to secure their withdrawal or elimination from the Western Hemisphere."
3. Action Plans: First among seven numbered steps was the following: "To halt this offensive buildup a strict quarantine on all offensive military equipment under shipment to Cuba is being initiated. All ships of any kind bound for Cuba from whatever nation or port will, if found to contain cargoes of offensive weapons, be turned back."

Rumelt wrote in 2011 that three important aspects of strategy include "premeditation, the anticipation of others' behavior, and the purposeful design of coordinated actions." He described strategy as solving a design problem, with trade-offs among various elements that must be arranged, adjusted and coordinated, rather than a plan or choice.

Formulation and implementation

Strategy typically involves two major processes: formulation and implementation. Formulation involves analyzing the environment or situation, making a diagnosis, and developing guiding policies. It includes such activities as strategic planning and strategic thinking. Implementation refers to the action plans taken to achieve the goals established by the guiding policy.

Bruce Henderson wrote in 1981 that: "Strategy depends upon the ability to foresee future consequences of present initiatives." He wrote that the basic requirements for strategy development include, among other factors: 1) extensive knowledge about the environment, market and competitors; 2) ability to examine this knowledge as an interactive dynamic system; and 3) the imagination and logic to choose between specific alternatives. Henderson wrote that strategy was valuable because of: "finite resources, uncertainty about an adversary's capability and intentions; the irreversible commitment of resources; necessity of coordinating action over time and distance; uncertainty about control of the initiative; and the nature of adversaries' mutual perceptions of each other."

Military theory

Subordinating the political point of view to the military would be absurd, for it is policy that has created war...Policy is the guiding intelligence, and war only the instrument, not vice-versa.

On War by Carl von Clausewitz

In military theory, strategy is "the utilization during both peace and war, of all of the nation's forces, through large scale, long-range planning and development, to ensure security and victory" (Random House Dictionary).

The father of Western modern strategic study, Carl von Clausewitz, defined military strategy as "the employment of battles to gain the end of war." B. H. Liddell Hart's definition put less emphasis on battles, defining strategy as "the art of distributing and applying military means to fulfill the ends of policy". Hence, both gave the pre-eminence to political aims over military goals. U.S. Naval War College instructor Andrew Wilson defined strategy as the "process by which political purpose is translated into military action." Lawrence Freedman defined strategy as the "art of creating power."

Eastern military philosophy dates back much further, with examples such as The Art of War by Sun Tzu dated around 500 B.C.

Management theory

The essence of formulating competitive strategy is relating a company to its environment.

Michael Porter

Modern business strategy emerged as a field of study and practice in the 1960s; prior to that time, the words "strategy" and "competition" rarely appeared in the most prominent management literature. Alfred Chandler wrote in 1962 that: "Strategy is the determination of the basic long-term goals of an enterprise, and the adoption of courses of action and the allocation of resources necessary for carrying out these goals." Michael Porter defined strategy in 1980 as the "...broad formula for how a business is going to compete, what its goals should be, and what policies will be needed to carry out those goals" and the "...combination of the ends (goals) for which the firm is striving and the means (policies) by which it is seeking to get there."

Henry Mintzberg described five definitions of strategy in 1998:

• Strategy as plan – a directed course of action to achieve an intended set of goals; similar to the strategic planning concept;
• Strategy as pattern – a consistent pattern of past behavior, with a strategy realized over time rather than planned or intended. Where the realized pattern was different from the intent, he referred to the strategy as emergent;
• Strategy as position – locating brands, products, or companies within the market, based on the conceptual framework of consumers or other stakeholders; a strategy determined primarily by factors outside the firm;
• Strategy as ploy – a specific maneuver intended to outwit a competitor; and
• Strategy as perspective – executing strategy based on a "theory of the business" or natural extension of the mindset or ideological perspective of the organization.

Strategies in game theory

In game theory, a strategy refers to the rules that a player uses to choose between the available actionable options. Every player in a non-trivial game has a set of possible strategies to use when choosing what moves to make.

A strategy may recursively look ahead and consider what actions can happen in each contingent state of the game—e.g. if the player takes action 1, then that presents the opponent with a certain situation, which might be good or bad, whereas if the player takes action 2 then the opponents will be presented with a different situation, and in each case the choices they make will determine their own future situation.

Strategies in game theory may be random (mixed) or deterministic (pure). Pure strategies can be thought of as a special case of mixed strategies, in which only probabilities 0 or 1 are assigned to actions.

Strategy based games generally require a player to think through a sequence of solutions to determine the best way to defeat the opponent.

Counterterrorism Strategy

Because counterterrorism involves the synchronized efforts of numerous competing bureaucratic entities, national governments frequently create overarching counterterrorism strategies at the national level. A national counterterrorism strategy is a government's plan to use the instruments of national power to neutralize terrorists, their organizations, and their networks in order to render them incapable of using violence to instill fear and to coerce the government or its citizens to react in accordance with the terrorists' goals. The United States has had several such strategies in the past, including the United States National Strategy for Counterterrorism (2018); the Obama-era National Strategy for Counterterrorism (2011); and the National Strategy for Combatting Terrorism (2003). There have also been a number of ancillary or supporting plans, such as the 2014 Strategy to Counter the Islamic State of Iraq and the Levant, and the 2016 Strategic Implementation Plan for Empowering Local Partners to Prevent Violent Extremism in the United States. Similarly, the United Kingdom's counterterrorism strategy, CONTEST, seeks "to reduce the risk to the UK and its citizens and interests overseas from terrorism, so that people can go about their lives freely and with confidence."

Boomerang effect (psychology)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Boomerang_effect_(psychology) 

In social psychology, the boomerang effect refers to the unintended consequences of an attempt to persuade resulting in the adoption of an opposing position instead. It is sometimes also referred to "the theory of psychological reactance", stating that attempts to restrict a person's freedom often produce an "anticonformity boomerang effect".

Conditions and explanations

Early recognition

Hovland, Janis and Kelly first recorded and named the boomerang effect in 1953, noting that it is more likely under certain conditions:

• When weak arguments are paired with a negative source.
• When weak or unclear persuasion leads the recipient to believe the communicator is trying to convince them of a different position than what the communicator intends.
• When the persuasion triggers aggression or unalleviated emotional arousal.
• When the communication adds to the recipient's knowledge of the norms and increases their conformity.
• When non-conformity to their own group results in feelings of guilt or social punishment.
• When the communicator's position is too far from the recipient's position and thus produces a "contrast" effect and thus enhances their original attitudes.

Later in 1957, Hovland, Sherif and Harvey further discussed the necessity of understanding these unintended attitude changes in persuasion communication and suggested possible approaches for analysis via underlying motivational processes, psychophysical stimuli, as well as ego-involving verbal material. Jack Brehm and Arthur Cohen were among the first to provide theoretical explanations.

Jack Brehm first raised attention to the phenomenon a fait accompli that might conceivably create dissonance if an event has led to the opposite behavior predicted at a prior point. He conducted an experiment to examine the behaviors of eighth graders eating a disliked vegetable. About half of them were told that their parents would be informed on the vegetable they ate. Then liking the vegetable was measured before and after the procedure. The results show that for kids who indicated little or no discrepancy between serving and actually eating the disliked vegetable at home, they should experience little or no dissonance in liking the vegetable from the low to the high consequence condition. They thereby concluded that the greater was the individual's initial dislike, the greater was the pressure produced by the experiment to increase his liking. There was also larger resistance to change the attitude when the initial attitude was more extreme. However, they argued that in this experiment, the pressure to reduce dissonance increased more rapidly with increasing discrepancy than did the resistance against change, which verified Festinger's cognitive dissonance theory. In a follow up, Sensenig and Brehm focused on the boomerang effect in experiments and applied Brehm's psychological reactance theory to explain the unintended attitudinal change.

Psychological reactance theory analysis

Sensenig & Brehm applied Brehm's reactance theory to explain the boomerang effect. They argued that when a person thinks that his freedom to support a position on attitude issue is eliminated, the psychological reactance will be aroused and then he consequently moves his attitudinal position in a way so as to restore the lost freedom. He told college students to write an essay supporting one side of five issues and led some of them believe that their persuasive essays might influence the decision on those issues. Therefore, the people who had the impression that their preference was taken into account in the decision regarding which side they would support on the 1st issue showed attitude change in favor of the preferred position, while others who are concerned with their freedom lost move toward the intended position held by the communicator.

This experiment resulted in various links in the chain of reasoning: (a) when a person's freedom is threatened, his motivational state will move toward restoration of the threatened freedom; (b) the greater the implied threatened freedoms, the greater the tendency to restore the threatened freedom will be; (c) the reestablishment of freedom may take the form of moving one's attitudinal position away from the position forced by others.

Jack Brehm and Sharon Brehm later developed psychological reactance theory and discussed its applications. They also listed a series of reactions reactance can evoke in addition to the boomerang effect, which includes but is not limited to related boomerang effect, indirect restoration or vicarious boomerang effects.

Cognitive dissonance theory analysis

The dissonance theory by Leon Festinger has thrived the progress of social psychology research in the 1960s as it is not confined to the prediction of intended influence but can support almost all sub fields of psychology studies. Although Festinger himself was ambiguous about the role of commitment in the theory, later researchers such as Brehm and Cohen have emphasized its importance in providing a general conceptualization of the boomerang effect. Earlier studies by Thibaut and Strickland and Kelley and Volkhart have also provided support to this line of reasoning by Dissonance Theory despite that they were not phrased using the exact terminology.

According to Cohen, dissonance theory can provide not only an explanation, but also a prediction of both the intended and the unintended influence of persuasion communication on attitudinal change. In his experiment, he presented factors that can lead to a boomerang effect, while suggesting a broader view of the unintended consequences than simply the case of a response to attempted attitude change. Cohen proposed the following dissonance formulation model for the unintended attitude change by persuasive communication. First, suppose that dissonance aroused in regard to some unspecified cognition. According to Festinger's Cognitive Dissonance Theory, we know the dissonance could be reduced by a change in the cognition. Now suppose the resistance to change is great because the actual event cannot be changed and its meaning is ambiguous (for example, the person is strongly committed to the original cognition position), then the person will resort to other forms to reduce or eliminate the dissonance. In this latter form, one can solve the discrepancy problem through the addition of elements consonant either with the original cognition, in which produced the boomerang effect. Cohen formulated a situation of "mutual boomerang effect", in which the communicator is strongly committed to convince the other person of his attitudinal position by means of a persuasion communication. Because of this strong original attitude position the communicator holds, Cohen predicts that the more distant the target person's original attitude, the more dissonance will be also experienced by the communicator. The expected "unintended influence" arises when the communicator tried to persuade the other of the worth of his own position by becoming even more extreme in that position. He asked his subjects write a strongly persuasive essay to the partners with an opposite side of attitude on an issue, who are actually confederates. The subjects here thus act as the communicator to bring their partners over to their own sides. The subjects were also asked to rate the partners' likability and friendliness before they read "their partner's essay" returned. Cohen used attitude change of the partners as the manipulation of dissonance where he randomly allocated his subjects into high-dissonance group and low-dissonance group. The results exposed strong boomerang effects for high-dissonance group. He also found out that the response to the likability and friendliness of the partners are relevant. The data showed that the difference between dissonance conditions was largely confined to and exaggerated for those subjects who originally rated their partners to be relatively more likable and friendly.

Cohen's study on boomerang effect has broadened the scope of persuasive communication from merely the recipient's reaction to the persuasive message to the communicator's attempt to influence the target. Dissonance theory suggests that the basic issue is under what conditions a person strengthens his original attitude as a way of reducing some attitudinal inconsistency. Cohen suggested that, one can reduce the dissonance via boomerang when dissonance is created (a) with a strong commitment to convincing the other person, (b) with no anticipation of a further influence attempt, and (c) with no easy chance to repudiate the other person. His results on the likability have strengthened the interpretation as the low-dissonance group who found their partners likable and friendly move toward them in the attitudes more, while likability only increased dissonance for the highs.

In other words, the dissonance can be reduced by becoming more extreme in the original position, thereby increasing the proportion of cognition supporting the initial stand and decreasing the proportion of dissonant cognition.

Other analysis

Boomerang effect is sometimes also referred to the attribution/attitude boomerang effect. Researchers applied Heider's attribution theory to explain why it would occur. For example, Skowronski, Carlston, Mae, and Crawford demonstrated association-based effects in their study on spontaneous trait transference. Despite that the descriptions of other people are independent of the communicator, simple associative processes link the two together and produce boomerang phenomena.

Examples of applications

Consumer behavior

Wendlandt and Schrader studied the resistance of consumers against loyalty programs encountered in relationship marketing. They found that (a) contractual bonds provoke reactance effects, (b) social-psychological bonds increased neither reactance nor perceived utility of the program, (c) economic bonds raised perceived utility to a certain threshold level, from which the reactance effect dominated afterwards. Their results helped managers to evaluate the effects from implementing consumer retention measures and advised a cautious and limited application of loyalty programs.

Deliberate exploitation

The tactic of reverse psychology, which is a deliberate exploitation of an anticipated boomerang effect, involves one's attempt of feigning a desire for an outcome opposite to that of the truly desired one, such that the prospect's resistance will work in the direction that the exploiter actually desires (e.g., "Please don't fling me in that briar patch").

Persuasive health communication

Researchers have reported that some public health interventions have produced effects opposite to those intended in health communication such as smoking and alcohol consumption behaviors, and thus have employed various methods to study them under different contexts. Ringold argued that some consumer's negative reactions on alcoholic beverage warnings and education efforts can be explained concisely by Brehm's psychological reactance theory. These results suggested that boomerang effects should be considered as potential costs of launching mass communication campaigns. Dillard and Shen also emphasized the importance of reactance theory to understand failures in persuasive health communication but argued that there be a measurement problem. They thereby developed four alternative conceptual perspectives on the nature of reactance as well as provided an empirical test of each.

Environmental behaviors

Mann and Hill investigated the case of litter control and showed that the combination of different positive influence strategies could actually create boomerang effect and decrease the amount of appropriate disposal of waste. Schultz et al. (2007) conducted a field experiment in which the normative messages were used to promote household energy conservation where they found the descriptive message of neighborhood usage created a boomerang effect depending on the high prior household consumption. They also eliminated the boomerang effect by adding an injunctive message about social approval. Their results offered an empirical evidence for prior research on the theoretical framework for boomerang effects.

Helping

Schwartz and Howard discussed the occurrence of boomerang effects in helping as they found out the presence of certain factors presumed to activate norms favoring helping actually result in decreasing helping. They identified three related forms of such boomerang effect in helping behavior. First, when individuals perceived the framing of a help appeal to have excessive statements of need, they become suspicious and concern the motive and the true severity of the original request (i.e., mistrust). Reactance theory was used to provide the second explanation. They stated that individuals would respond to threatened freedoms by either acting counter to the attempted social influence, or declaring themselves helpless. The third type involves undermining internalized benefits by external sanctions.

National and human security

Liotta attempted to understand policy decisions and future choices driven by a blurring of concerns that involve state-centric security and human security. She suggested that a boomerang effect occurs in the area in which excessive focus on one aspect of security at the expense or detriment of the other is a poor balancing of ends and means in a changing security environment and instead we should focus on both national and human security.

Political beliefs

Nyhan & Reifler conducted experiments in which subjects read mock news articles including a misleading claim from a politician, or such a claim followed by a correction. They found that the corrections frequently fail to reduce misconceptions for the ideological group targeted by the misinformation. They also found cases of what they called a "backfire effect" (i.e. a boomerang effect) in which the corrections strengthened belief in the misinformation. They attribute this to motivated reasoning on the part of the affected participants. Later research did not find evidence of this effect though, suggesting it was at least not prevalent.