Big data is a field that treats of ways to analyze, systematically extract information from, or otherwise deal with data sets that are too large or complex to be dealt with by traditional data-processing application software. Data with many cases (rows) offer greater statistical power, while data with higher complexity (more attributes or columns) may lead to a higher false discovery rate. Big data challenges include capturing data, data storage, data analysis, search, sharing, transfer, visualization, querying, updating, information privacy and data source. Big data was originally associated with three key concepts: volume, variety, and velocity. Other concepts later attributed with big data are veracity (i.e., how much noise is in the data) and value.
Current usage of the term big data tends to refer to the use of predictive analytics, user behavior analytics,
or certain other advanced data analytics methods that extract value
from data, and seldom to a particular size of data set. "There is little
doubt that the quantities of data now available are indeed large, but
that's not the most relevant characteristic of this new data ecosystem."
Analysis of data sets can find new correlations to "spot business trends, prevent diseases, combat crime and so on." Scientists, business executives, practitioners of medicine, advertising and governments alike regularly meet difficulties with large data-sets in areas including Internet search, fintech, urban informatics, and business informatics. Scientists encounter limitations in e-Science work, including meteorology, genomics, connectomics, complex physics simulations, biology and environmental research.
Data sets grow rapidly- in part because they are increasingly gathered by cheap and numerous information- sensing Internet of things devices such as mobile devices, aerial (remote sensing), software logs, cameras, microphones, radio-frequency identification (RFID) readers and wireless sensor networks. The world's technological per-capita capacity to store information has roughly doubled every 40 months since the 1980s; as of 2012, every day 2.5 exabytes (2.5×1018) of data are generated. Based on an IDC report prediction, the global data volume will grow exponentially from 4.4 zettabytes to 44 zettabytes between 2013 and 2020. By 2025, IDC predicts there will be 163 zettabytes of data. One question for large enterprises is determining who should own big-data initiatives that affect the entire organization.
Relational database management systems, desktop statistics
and software packages used to visualize data often have difficulty
handling big data. The work may require "massively parallel software
running on tens, hundreds, or even thousands of servers".
What qualifies as being "big data" varies depending on the capabilities
of the users and their tools, and expanding capabilities make big data a
moving target. "For some organizations, facing hundreds of gigabytes of
data for the first time may trigger a need to reconsider data
management options. For others, it may take tens or hundreds of
terabytes before data size becomes a significant consideration."
Definition
The term has been in use since the 1990s, with some giving credit to John Mashey for popularizing the term.
Big data usually includes data sets with sizes beyond the ability of commonly used software tools to capture, curate, manage, and process data within a tolerable elapsed time.
Big data philosophy encompasses unstructured, semi-structured and
structured data, however the main focus is on unstructured data. Big data "size" is a constantly moving target, as of 2012 ranging from a few dozen terabytes to many exabytes of data.
Big data requires a set of techniques and technologies with new forms of
integration to reveal insights from datasets that are diverse, complex,
and of a massive scale.
A 2016 definition states that "Big data represents the
information assets characterized by such a high volume, velocity and
variety to require specific technology and analytical methods for its
transformation into value". Similarly, Kaplan
and Haenlein define big data as "data sets characterized by huge
amounts (volume) of frequently updated data (velocity) in various
formats, such as numeric, textual, or images/videos (variety)." Additionally, a new V, veracity, is added by some organizations to describe it, revisionism challenged by some industry authorities. The three Vs (volume, variety and velocity) have been further expanded to other complementary characteristics of big data:
- Machine learning: big data often doesn't ask why and simply detects patterns
- Digital footprint: big data is often a cost-free byproduct of digital interaction
A 2018 definition states "Big data is where parallel computing tools
are needed to handle data", and notes, "This represents a distinct and
clearly defined change in the computer science used, via parallel
programming theories, and losses of
some of the guarantees and capabilities made by Codd's relational model."
The growing maturity of the concept more starkly delineates the difference between "big data" and "Business Intelligence":
- Business Intelligence uses descriptive statistics with data with high information density to measure things, detect trends, etc.
- Big data uses inductive statistics and concepts from nonlinear system identification to infer laws (regressions, nonlinear relationships, and causal effects) from large sets of data with low information density to reveal relationships and dependencies, or to perform predictions of outcomes and behaviors.
Characteristics
Big data can be described by the following characteristics:
- Volume
- The quantity of generated and stored data. The size of the data determines the value and potential insight, and whether it can be considered big data or not.
- Variety
- The type and nature of the data. This helps people who analyze it to effectively use the resulting insight. Big data draws from text, images, audio, video; plus it completes missing pieces through data fusion.
- Velocity
- In this context, the speed at which the data is generated and processed to meet the demands and challenges that lie in the path of growth and development. Big data is often available in real-time. Compared to small data, big data are produced more continually. Two kinds of velocity related to big data are the frequency of generation and the frequency of handling, recording, and publishing.
- Veracity
- It is the extended definition for big data, which refers to the data quality and the data value. The data quality of captured data can vary greatly, affecting the accurate analysis.
Data must be processed with advanced tools (analytics and algorithms)
to reveal meaningful information. For example, to manage a factory one
must consider both visible and invisible issues with various components.
Information generation algorithms must detect and address invisible
issues such as machine degradation, component wear, etc. on the factory
floor.
Architecture
Big
data repositories have existed in many forms, often built by
corporations with a special need. Commercial vendors historically
offered parallel database management systems for big data beginning in
the 1990s. For many years, WinterCorp published a largest database
report.
Teradata Corporation in 1984 marketed the parallel processing DBC 1012
system. Teradata systems were the first to store and analyze 1 terabyte
of data in 1992. Hard disk drives were 2.5 GB in 1991 so the definition
of big data continuously evolves according to Kryder's Law. Teradata
installed the first petabyte class RDBMS based system in 2007. As of
2017, there are a few dozen petabyte class Teradata relational databases
installed, the largest of which exceeds 50 PB. Systems up until 2008
were 100% structured relational data. Since then, Teradata has added
unstructured data types including XML, JSON, and Avro.
In 2000, Seisint Inc. (now LexisNexis Group)
developed a C++-based distributed file-sharing framework for data
storage and query. The system stores and distributes structured,
semi-structured, and unstructured data across multiple servers. Users can build queries in a C++ dialect called ECL.
ECL uses an "apply schema on read" method to infer the structure of
stored data when it is queried, instead of when it is stored. In 2004,
LexisNexis acquired Seisint Inc. and in 2008 acquired ChoicePoint, Inc. and their high-speed parallel processing platform. The two platforms were merged into HPCC (or High-Performance Computing Cluster) Systems and in 2011, HPCC was open-sourced under the Apache v2.0 License. Quantcast File System was available about the same time.
CERN and other physics experiments have collected big data sets for many decades, usually analyzed via high performance computing (supercomputers) rather than the commodity map-reduce architectures usually meant by the current "big data" movement.
In 2004, Google published a paper on a process called MapReduce
that uses a similar architecture. The MapReduce concept provides a
parallel processing model, and an associated implementation was released
to process huge amounts of data. With MapReduce, queries are split and
distributed across parallel nodes and processed in parallel (the Map
step). The results are then gathered and delivered (the Reduce step).
The framework was very successful,
so others wanted to replicate the algorithm. Therefore, an
implementation of the MapReduce framework was adopted by an Apache
open-source project named Hadoop. Apache Spark
was developed in 2012 in response to limitations in the MapReduce
paradigm, as it adds the ability to set up many operations (not just map
followed by reduce).
MIKE2.0
is an open approach to information management that acknowledges the
need for revisions due to big data implications identified in an article
titled "Big Data Solution Offering". The methodology addresses handling big data in terms of useful permutations of data sources, complexity in interrelationships, and difficulty in deleting (or modifying) individual records.
2012 studies showed that a multiple-layer architecture is one option to address the issues that big data presents. A distributed parallel
architecture distributes data across multiple servers; these parallel
execution environments can dramatically improve data processing speeds.
This type of architecture inserts data into a parallel DBMS, which
implements the use of MapReduce and Hadoop frameworks. This type of
framework looks to make the processing power transparent to the end user
by using a front-end application server.
The data lake
allows an organization to shift its focus from centralized control to a
shared model to respond to the changing dynamics of information
management. This enables quick segregation of data into the data lake,
thereby reducing the overhead time.
Big data analytics for manufacturing applications is marketed as a "5C architecture" (connection, conversion, cyber, cognition, and configuration).
Factory work and Cyber-physical systems may have an extended "6C system":
- Connection (sensor and networks)
- Cloud (computing and data on demand)
- Cyber (model and memory)
- Content/context (meaning and correlation)
- Community (sharing and collaboration)
- Customization (personalization and value)
Technologies
A 2011 McKinsey Global Institute report characterizes the main components and ecosystem of big data as follows:
- Techniques for analyzing data, such as A/B testing, machine learning and natural language processing
- Big data technologies, like business intelligence, cloud computing and databases
- Visualization, such as charts, graphs and other displays of the data
Multidimensional big data can also be represented as data cubes or, mathematically, tensors. Array Database Systems have set out to provide storage and high-level query support on this data type.
Additional technologies being applied to big data include efficient tensor-based computation, such as multilinear subspace learning., massively parallel-processing (MPP) databases, search-based applications, data mining, distributed file systems, distributed databases, cloud and HPC-based infrastructure (applications, storage and computing resources) and the Internet.
Although, many approaches and technologies have been developed, it
still remains difficult to carry out machine learning with big data.
Some MPP
relational databases have the ability to store and manage petabytes of
data. Implicit is the ability to load, monitor, back up, and optimize
the use of the large data tables in the RDBMS.
DARPA's Topological Data Analysis
program seeks the fundamental structure of massive data sets and in
2008 the technology went public with the launch of a company called Ayasdi.
The practitioners of big data analytics processes are generally hostile to slower shared storage, preferring direct-attached storage (DAS) in its various forms from solid state drive (SSD) to high capacity SATA disk buried inside parallel processing nodes. The perception of shared storage architectures—Storage area network (SAN) and Network-attached storage
(NAS) —is that they are relatively slow, complex, and expensive. These
qualities are not consistent with big data analytics systems that thrive
on system performance, commodity infrastructure, and low cost.
Real or near-real time information delivery is one of the
defining characteristics of big data analytics. Latency is therefore
avoided whenever and wherever possible. Data in memory is good—data on
spinning disk at the other end of a FC SAN connection is not. The cost of a SAN at the scale needed for analytics applications is very much higher than other storage techniques.
There are advantages as well as disadvantages to shared storage
in big data analytics, but big data analytics practitioners as of 2011 did not favour it.
Applications
Big data has increased the demand of information management specialists so much so that Software AG, Oracle Corporation, IBM, Microsoft, SAP, EMC, HP and Dell
have spent more than $15 billion on software firms specializing in data
management and analytics. In 2010, this industry was worth more than
$100 billion and was growing at almost 10 percent a year: about twice as
fast as the software business as a whole.
Developed economies increasingly use data-intensive technologies.
There are 4.6 billion mobile-phone subscriptions worldwide, and between
1 billion and 2 billion people accessing the internet.
Between 1990 and 2005, more than 1 billion people worldwide entered the
middle class, which means more people became more literate, which in
turn led to information growth. The world's effective capacity to
exchange information through telecommunication networks was 281 petabytes in 1986, 471 petabytes in 1993, 2.2 exabytes in 2000, 65 exabytes in 2007 and predictions put the amount of internet traffic at 667 exabytes annually by 2014.
According to one estimate, one-third of the globally stored information
is in the form of alphanumeric text and still image data,
which is the format most useful for most big data applications. This
also shows the potential of yet unused data (i.e. in the form of video
and audio content).
While many vendors offer off-the-shelf solutions for big data,
experts recommend the development of in-house solutions custom-tailored
to solve the company's problem at hand if the company has sufficient
technical capabilities.
Government
The
use and adoption of big data within governmental processes allows
efficiencies in terms of cost, productivity, and innovation,
but does not come without its flaws. Data analysis often requires
multiple parts of government (central and local) to work in
collaboration and create new and innovative processes to deliver the
desired outcome.
CRVS (Civil Registration and Vital Statistics) collects all certificates status from birth to death. CRVS is a source of big data for governments.
International development
Research on the effective usage of information and communication technologies for development (also known as ICT4D) suggests that big data technology can make important contributions but also present unique challenges to International development.
Advancements in big data analysis offer cost-effective opportunities to
improve decision-making in critical development areas such as health
care, employment, economic productivity, crime, security, and natural disaster and resource management. Additionally, user-generated data offers new opportunities to give the unheard a voice.
However, longstanding challenges for developing regions such as
inadequate technological infrastructure and economic and human resource
scarcity exacerbate existing concerns with big data such as privacy,
imperfect methodology, and interoperability issues.
Manufacturing
Based
on TCS 2013 Global Trend Study, improvements in supply planning and
product quality provide the greatest benefit of big data for
manufacturing. Big data provides an infrastructure for transparency in
manufacturing industry, which is the ability to unravel uncertainties
such as inconsistent component performance and availability. Predictive
manufacturing as an applicable approach toward near-zero downtime and
transparency requires vast amount of data and advanced prediction tools
for a systematic process of data into useful information.
A conceptual framework of predictive manufacturing begins with data
acquisition where different type of sensory data is available to acquire
such as acoustics, vibration, pressure, current, voltage and controller
data. Vast amount of sensory data in addition to historical data
construct the big data in manufacturing. The generated big data acts as
the input into predictive tools and preventive strategies such as Prognostics and Health Management (PHM).
Healthcare
Big
data analytics has helped healthcare improve by providing personalized
medicine and prescriptive analytics, clinical risk intervention and
predictive analytics, waste and care variability reduction, automated
external and internal reporting of patient data, standardized medical
terms and patient registries and fragmented point solutions.
Some areas of improvement are more aspirational than actually
implemented. The level of data generated within healthcare systems is
not trivial. With the added adoption of mHealth, eHealth and wearable
technologies the volume of data will continue to increase. This includes
electronic health record
data, imaging data, patient generated data, sensor data, and other
forms of difficult to process data. There is now an even greater need
for such environments to pay greater attention to data and information
quality. "Big data very often means 'dirty data'
and the fraction of data inaccuracies increases with data volume
growth." Human inspection at the big data scale is impossible and there
is a desperate need in health service for intelligent tools for accuracy
and believability control and handling of information missed.
While extensive information in healthcare is now electronic, it fits
under the big data umbrella as most is unstructured and difficult to
use.
The use of big data in healthcare has raised significant ethical
challenges ranging from risks for individual rights, privacy and
autonomy, to transparency and trust.
Education
A McKinsey Global Institute study found a shortage of 1.5 million highly trained data professionals and managers and a number of universities including University of Tennessee and UC Berkeley,
have created masters programs to meet this demand. Private bootcamps
have also developed programs to meet that demand, including free
programs like The Data Incubator or paid programs like General Assembly. In the specific field of marketing, one of the problems stressed by Wedel and Kannan
is that marketing has several subdomains (e.g., advertising,
promotions,
product development, branding) that all use different types of data.
Because one-size-fits-all analytical solutions are not desirable,
business schools should prepare marketing managers to have wide
knowledge on all the different techniques used in these subdomains to
get a big picture and work effectively with analysts.
Media
To
understand how the media utilizes big data, it is first necessary to
provide some context into the mechanism used for media process. It has
been suggested by Nick Couldry and Joseph Turow that practitioners
in Media and Advertising approach big data as many actionable points of
information about millions of individuals. The industry appears to be
moving away from the traditional approach of using specific media
environments such as newspapers, magazines, or television shows and
instead taps into consumers with technologies that reach targeted people
at optimal times in optimal locations. The ultimate aim is to serve or
convey, a message or content that is (statistically speaking) in line
with the consumer's mindset. For example, publishing environments are
increasingly tailoring messages (advertisements) and content (articles)
to appeal to consumers that have been exclusively gleaned through
various data-mining activities.
- Targeting of consumers (for advertising by marketers)
- Data capture
- Data journalism: publishers and journalists use big data tools to provide unique and innovative insights and infographics.
Channel 4, the British public-service television broadcaster, is a leader in the field of big data and data analysis.
Insurance
Health insurance providers are collecting data on social "determinants of health" such as food and TV consumption,
marital status, clothing size and purchasing habits, from which they
make predictions on health costs, in order to spot health issues in
their clients. It is controversial whether these predictions are
currently being used for pricing.
Internet of Things (IoT)
Big data and the IoT work in conjunction. Data extracted from IoT
devices provides a mapping of device interconnectivity. Such mappings
have been used by the media industry, companies and governments to more
accurately target their audience and increase media efficiency. IoT is
also increasingly adopted as a means of gathering sensory data, and this
sensory data has been used in medical, manufacturing and transportation contexts.
Kevin Ashton, digital innovation expert who is credited with coining the term,
defines the Internet of Things in this quote: “If we had computers that
knew everything there was to know about things—using data they gathered
without any help from us—we would be able to track and count
everything, and greatly reduce waste, loss and cost. We would know when
things needed replacing, repairing or recalling, and whether they were
fresh or past their best.”
Information Technology
Especially since 2015, big data has come to prominence within Business Operations as a tool to help employees work more efficiently and streamline the collection and distribution of Information Technology (IT). The use of big data to resolve IT and data collection issues within an enterprise is called IT Operations Analytics (ITOA). By applying big data principles into the concepts of machine intelligence and deep computing, IT departments can predict potential issues and move to provide solutions before the problems even happen. In this time, ITOA businesses were also beginning to play a major role in systems management by offering platforms that brought individual data silos together and generated insights from the whole of the system rather than from isolated pockets of data.
Case studies
Government
China
- The Integrated Joint Operations Platform (IJOP, 一体化联合作战平台) is used by the government to monitor the population, particularly Uyghurs. Biometrics, including DNA samples, are gathered though a program of free physicals.
India
- Big data analysis was tried out for the BJP to win the Indian General Election 2014.
- The Indian government utilizes numerous techniques to ascertain how the Indian electorate is responding to government action, as well as ideas for policy augmentation.
Israel
- A big data application was designed by Agro Web Lab to aid irrigation regulation.
- Personalized diabetic treatments can be created through GlucoMe's big data solution.
United Kingdom
Examples of uses of big data in public services:
- Data on prescription drugs: by connecting origin, location and the time of each prescription, a research unit was able to exemplify the considerable delay between the release of any given drug, and a UK-wide adaptation of the National Institute for Health and Care Excellence guidelines. This suggests that new or most up-to-date drugs take some time to filter through to the general patient.
- Joining up data: a local authority blended data about services, such as road gritting rotas, with services for people at risk, such as 'meals on wheels'. The connection of data allowed the local authority to avoid any weather-related delay.
United States of America
- In 2012, the Obama administration announced the Big Data Research and Development Initiative, to explore how big data could be used to address important problems faced by the government. The initiative is composed of 84 different big data programs spread across six departments.
- Big data analysis played a large role in Barack Obama's successful 2012 re-election campaign.
- The United States Federal Government owns five of the ten most powerful supercomputers in the world.
- The Utah Data Center has been constructed by the United States National Security Agency. When finished, the facility will be able to handle a large amount of information collected by the NSA over the Internet. The exact amount of storage space is unknown, but more recent sources claim it will be on the order of a few exabytes. This has posed security concerns regarding the anonymity of the data collected.
Retail
- Walmart handles more than 1 million customer transactions every hour, which are imported into databases estimated to contain more than 2.5 petabytes (2560 terabytes) of data—the equivalent of 167 times the information contained in all the books in the US Library of Congress.
- Windermere Real Estate uses location information from nearly 100 million drivers to help new home buyers determine their typical drive times to and from work throughout various times of the day.
- FICO Card Detection System protects accounts worldwide.
Science
- The Large Hadron Collider
experiments represent about 150 million sensors delivering data
40 million times per second. There are nearly 600 million collisions per
second. After filtering and refraining from recording more than
99.99995% of these streams, there are 100 collisions of interest per second.
- As a result, only working with less than 0.001% of the sensor stream data, the data flow from all four LHC experiments represents 25 petabytes annual rate before replication (as of 2012). This becomes nearly 200 petabytes after replication.
- If all sensor data were recorded in LHC, the data flow would be extremely hard to work with. The data flow would exceed 150 million petabytes annual rate, or nearly 500 exabytes per day, before replication. To put the number in perspective, this is equivalent to 500 quintillion (5×1020) bytes per day, almost 200 times more than all the other sources combined in the world.
- The Square Kilometre Array is a radio telescope built of thousands of antennas. It is expected to be operational by 2024. Collectively, these antennas are expected to gather 14 exabytes and store one petabyte per day. It is considered one of the most ambitious scientific projects ever undertaken.
- When the Sloan Digital Sky Survey (SDSS) began to collect astronomical data in 2000, it amassed more in its first few weeks than all data collected in the history of astronomy previously. Continuing at a rate of about 200 GB per night, SDSS has amassed more than 140 terabytes of information. When the Large Synoptic Survey Telescope, successor to SDSS, comes online in 2020, its designers expect it to acquire that amount of data every five days.
- Decoding the human genome originally took 10 years to process; now it can be achieved in less than a day. The DNA sequencers have divided the sequencing cost by 10,000 in the last ten years, which is 100 times cheaper than the reduction in cost predicted by Moore's Law.
- The NASA Center for Climate Simulation (NCCS) stores 32 petabytes of climate observations and simulations on the Discover supercomputing cluster.
- Google's DNAStack compiles and organizes DNA samples of genetic data from around the world to identify diseases and other medical defects. These fast and exact calculations eliminate any 'friction points,' or human errors that could be made by one of the numerous science and biology experts working with the DNA. DNAStack, a part of Google Genomics, allows scientists to use the vast sample of resources from Google's search server to scale social experiments that would usually take years, instantly.
- 23andme's DNA database contains genetic information of over 1,000,000 people worldwide. The company explores selling the "anonymous aggregated genetic data" to other researchers and pharmaceutical companies for research purposes if patients give their consent. Ahmad Hariri, professor of psychology and neuroscience at Duke University who has been using 23andMe in his research since 2009 states that the most important aspect of the company's new service is that it makes genetic research accessible and relatively cheap for scientists. A study that identified 15 genome sites linked to depression in 23andMe's database lead to a surge in demands to access the repository with 23andMe fielding nearly 20 requests to access the depression data in the two weeks after publication of the paper.
- Computational Fluid Dynamics (CFD) and hydrodynamic turbulence research generate massive datasets. The Johns Hopkins Turbulence Databases (JHTDB) contains over 350 terabytes of spatiotemporal fields from Direct Numerical simulations of various turbulent flows. Such data have been difficult to share using traditional methods such as downloading flat simulation output files. The data within JHTDB can be accessed using "virtual sensors" with various access modes ranging from direct web-browser queries, access through Matlab, Python, Fortran and C programs executing on clients' platforms, to cut out services to download raw data. The data have been used in over 150 scientific publications.
Sports
Big data
can be used to improve training and understanding competitors, using
sport sensors. It is also possible to predict winners in a match using
big data analytics.
Future performance of players could be predicted as well. Thus, players'
value and salary is determined by data collected throughout the season.
In Formula One races, race cars with hundreds of sensors generate
terabytes of data. These sensors collect data points from tire pressure
to fuel burn efficiency.
Based on the data, engineers and data analysts decide whether
adjustments should be made in order to win a race. Besides, using big
data, race teams try to predict the time they will finish the race
beforehand, based on simulations using data collected over the season.
Technology
- eBay.com uses two data warehouses at 7.5 petabytes and 40PB as well as a 40PB Hadoop cluster for search, consumer recommendations, and merchandising.
- Amazon.com handles millions of back-end operations every day, as well as queries from more than half a million third-party sellers. The core technology that keeps Amazon running is Linux-based and as of 2005 they had the world's three largest Linux databases, with capacities of 7.8 TB, 18.5 TB, and 24.7 TB.
- Facebook handles 50 billion photos from its user base. As of June 2017, Facebook reached 2 billion monthly active users.
- Google was handling roughly 100 billion searches per month as of August 2012.
Research activities
Encrypted
search and cluster formation in big data were demonstrated in March
2014 at the American Society of Engineering Education. Gautam Siwach
engaged at Tackling the challenges of Big Data by MIT Computer Science and Artificial Intelligence Laboratory
and Dr. Amir Esmailpour at UNH Research Group investigated the key
features of big data as the formation of clusters and their
interconnections. They focused on the security of big data and the
orientation of the term towards the presence of different type of data
in an encrypted form at cloud interface by providing the raw definitions
and real time examples within the technology. Moreover, they proposed
an approach for identifying the encoding technique to advance towards an
expedited search over encrypted text leading to the security
enhancements in big data.
In March 2012, The White House announced a national "Big Data
Initiative" that consisted of six Federal departments and agencies
committing more than $200 million to big data research projects.
The initiative included a National Science Foundation "Expeditions in Computing" grant of $10 million over 5 years to the AMPLab at the University of California, Berkeley. The AMPLab also received funds from DARPA, and over a dozen industrial sponsors and uses big data to attack a wide range of problems from predicting traffic congestion to fighting cancer.
The White House Big Data Initiative also included a commitment by
the Department of Energy to provide $25 million in funding over 5
years to establish the Scalable Data Management, Analysis and
Visualization (SDAV) Institute, led by the Energy Department's Lawrence Berkeley National Laboratory.
The SDAV Institute aims to bring together the expertise of six national
laboratories and seven universities to develop new tools to help
scientists manage and visualize data on the Department's supercomputers.
The U.S. state of Massachusetts
announced the Massachusetts Big Data Initiative in May 2012, which
provides funding from the state government and private companies to a
variety of research institutions. The Massachusetts Institute of Technology hosts the Intel Science and Technology Center for Big Data in the MIT Computer Science and Artificial Intelligence Laboratory, combining government, corporate, and institutional funding and research efforts.
The European Commission is funding the 2-year-long Big Data Public Private Forum through their Seventh Framework Program
to engage companies, academics and other stakeholders in discussing big
data issues. The project aims to define a strategy in terms of research
and innovation to guide supporting actions from the European Commission
in the successful implementation of the big data economy. Outcomes of
this project will be used as input for Horizon 2020, their next framework program.
The British government announced in March 2014 the founding of the Alan Turing Institute, named after the computer pioneer and code-breaker, which will focus on new ways to collect and analyse large data sets.
At the University of Waterloo Stratford Campus
Canadian Open Data Experience (CODE) Inspiration Day, participants
demonstrated how using data visualization can increase the understanding
and appeal of big data sets and communicate their story to the world.
To make manufacturing more competitive in the United States (and
globe), there is a need to integrate more American ingenuity and
innovation into manufacturing ; Therefore, National Science Foundation
has granted the Industry University cooperative research center for
Intelligent Maintenance Systems (IMS) at university of Cincinnati to focus on developing advanced predictive tools and techniques to be applicable in a big data environment.
In May 2013, IMS Center held an industry advisory board meeting
focusing on big data where presenters from various industrial companies
discussed their concerns, issues and future goals in big data
environment.
Computational social sciences – Anyone can use Application
Programming Interfaces (APIs) provided by big data holders, such as
Google and Twitter, to do research in the social and behavioral
sciences. Often these APIs are provided for free. Tobias Preis et al. used Google Trends
data to demonstrate that Internet users from countries with a higher
per capita gross domestic product (GDP) are more likely to search for
information about the future than information about the past. The
findings suggest there may be a link between online behaviour and
real-world economic indicators.
The authors of the study examined Google queries logs made by ratio of
the volume of searches for the coming year ('2011') to the volume of
searches for the previous year ('2009'), which they call the 'future orientation index'.
They compared the future orientation index to the per capita GDP of
each country, and found a strong tendency for countries where Google
users inquire more about the future to have a higher GDP. The results
hint that there may potentially be a relationship between the economic
success of a country and the information-seeking behavior of its
citizens captured in big data.
Tobias Preis and his colleagues Helen Susannah Moat and H. Eugene Stanley
introduced a method to identify online precursors for stock market
moves, using trading strategies based on search volume data provided by
Google Trends. Their analysis of Google search volume for 98 terms of varying financial relevance, published in Scientific Reports,
suggests that increases in search volume for financially relevant
search terms tend to precede large losses in financial markets.
Big data sets come with algorithmic challenges that previously
did not exist. Hence, there is a need to fundamentally change the
processing ways.
The Workshops on Algorithms for Modern Massive Data Sets (MMDS)
bring together computer scientists, statisticians, mathematicians, and
data analysis practitioners to discuss algorithmic challenges of big
data.
Sampling big data
An
important research question that can be asked about big data sets is
whether you need to look at the full data to draw certain conclusions
about the properties of the data or is a sample good enough. The name
big data itself contains a term related to size and this is an important
characteristic of big data. But Sampling (statistics)
enables the selection of right data points from within the larger data
set to estimate the characteristics of the whole population. For
example, there are about 600 million tweets produced every day. Is it
necessary to look at all of them to determine the topics that are
discussed during the day? Is it necessary to look at all the tweets to
determine the sentiment on each of the topics? In manufacturing
different types of sensory data such as acoustics, vibration, pressure,
current, voltage and controller data are available at short time
intervals. To predict downtime it may not be necessary to look at all
the data but a sample may be sufficient. Big Data can be broken down by
various data point categories such as demographic, psychographic,
behavioral, and transactional data. With large sets of data points,
marketers are able to create and utilize more customized segments of
consumers for more strategic targeting.
There has been some work done in Sampling algorithms for big
data. A theoretical formulation for sampling Twitter data has been
developed.
Critique
Critiques
of the big data paradigm come in two flavors, those that question the
implications of the approach itself, and those that question the way it
is currently done. One approach to this criticism is the field of critical data studies.
Critiques of the big data paradigm
"A
crucial problem is that we do not know much about the underlying
empirical micro-processes that lead to the emergence of the[se] typical
network characteristics of Big Data". In their critique, Snijders, Matzat, and Reips
point out that often very strong assumptions are made about
mathematical properties that may not at all reflect what is really going
on at the level of micro-processes. Mark Graham has leveled broad
critiques at Chris Anderson's assertion that big data will spell the end of theory:
focusing in particular on the notion that big data must always be
contextualized in their social, economic, and political contexts.
Even as companies invest eight- and nine-figure sums to derive insight
from information streaming in from suppliers and customers, less than
40% of employees have sufficiently mature processes and skills to do so.
To overcome this insight deficit, big data, no matter how comprehensive
or well analyzed, must be complemented by "big judgment," according to
an article in the Harvard Business Review.
Much in the same line, it has been pointed out that the decisions
based on the analysis of big data are inevitably "informed by the world
as it was in the past, or, at best, as it currently is".
Fed by a large number of data on past experiences, algorithms can
predict future development if the future is similar to the past. If the systems dynamics of the future change (if it is not a stationary process),
the past can say little about the future. In order to make predictions
in changing environments, it would be necessary to have a thorough
understanding of the systems dynamic, which requires theory.
As a response to this critique Alemany Oliver and Vayre suggest to use
"abductive reasoning as a first step in the research process in order
to bring context to consumers' digital traces and make new theories
emerge".
Additionally, it has been suggested to combine big data approaches with computer simulations, such as agent-based models and complex systems.
Agent-based models are increasingly getting better in predicting the
outcome of social complexities of even unknown future scenarios through
computer simulations that are based on a collection of mutually
interdependent algorithms. Finally, use of multivariate methods that probe for the latent structure of the data, such as factor analysis and cluster analysis,
have proven useful as analytic approaches that go well beyond the
bi-variate approaches (cross-tabs) typically employed with smaller data
sets.
In health and biology, conventional scientific approaches are
based on experimentation. For these approaches, the limiting factor is
the relevant data that can confirm or refute the initial hypothesis.
A new postulate is accepted now in biosciences: the information provided by the data in huge volumes (omics) without prior hypothesis is complementary and sometimes necessary to conventional approaches based on experimentation. In the massive approaches it is the formulation of a relevant hypothesis to explain the data that is the limiting factor. The search logic is reversed and the limits of induction ("Glory of Science and Philosophy scandal", C. D. Broad, 1926) are to be considered.
Privacy advocates are concerned about the threat to privacy represented by increasing storage and integration of personally identifiable information; expert panels have released various policy recommendations to conform practice to expectations of privacy.
The misuse of Big Data in several cases by media, companies and even
the government has allowed for abolition of trust in almost every
fundamental institution holding up society.
Nayef Al-Rodhan argues that a new kind of social contract will be
needed to protect individual liberties in a context of Big Data and
giant corporations that own vast amounts of information. The use of Big
Data should be monitored and better regulated at the national and
international levels.
Barocas and Nissenbaum argue that one way of protecting individual
users is by being informed about the types of information being
collected, with whom it is shared, under what constrains and for what
purposes.
Critiques of the 'V' model
The
'V' model of Big Data is concerting as it centres around computational
scalability and lacks in a loss around the perceptibility and
understandability of information. This led to the framework of cognitive big data, which characterises Big Data application according to:
- Data completeness: understanding of the non-obvious from data;
- Data correlation, causation, and predictability: causality as not essential requirement to achieve predictability;
- Explainability and interpretability: humans desire to understand and accept what they understand, where algorithms don't cope with this;
- Level of automated decision making: algorithms that support automated decision making and algorithmic self-learning.
Critiques of novelty
Large
data sets have been analyzed by computing machines for well over a
century, including the 1890s US census analytics performed by IBM's
punch card machines which computed statistics including means and
variances of populations across the whole continent. In more recent
decades, science experiments such as CERN
have produced data on similar scales to current commercial "big data".
However science experiments have tended to analyze their data using
specialized custom-built high performance computing
(supercomputing) clusters and grids, rather than clouds of cheap
commodity computers as in the current commercial wave, implying a
difference in both culture and technology stack.
Critiques of big data execution
Ulf-Dietrich Reips and Uwe Matzat wrote in 2014 that big data had become a "fad" in scientific research. Researcher Danah Boyd has raised concerns about the use of big data in science neglecting principles such as choosing a representative sample by being too concerned about handling the huge amounts of data. This approach may lead to results bias
in one way or another. Integration across heterogeneous data
resources—some that might be considered big data and others not—presents
formidable logistical as well as analytical challenges, but many
researchers argue that such integrations are likely to represent the
most promising new frontiers in science.
In the provocative article "Critical Questions for Big Data", the authors title big data a part of mythology:
"large data sets offer a higher form of intelligence and knowledge
[...], with the aura of truth, objectivity, and accuracy". Users of big
data are often "lost in the sheer volume of numbers", and "working with
Big Data is still subjective, and what it quantifies does not
necessarily have a closer claim on objective truth".
Recent developments in BI domain, such as pro-active reporting
especially target improvements in usability of big data, through
automated filtering of non-useful data and correlations.
Big data analysis is often shallow compared to analysis of smaller data sets. In many big data projects, there is no large data analysis happening, but the challenge is the extract, transform, load part of data preprocessing.
Big data is a buzzword and a "vague term", but at the same time an "obsession" with entrepreneurs, consultants, scientists and the media. Big data showcases such as Google Flu Trends failed to deliver good predictions in recent years, overstating the flu outbreaks by a factor of two. Similarly, Academy awards
and election predictions solely based on Twitter were more often off
than on target.
Big data often poses the same challenges as small data; adding more data
does not solve problems of bias, but may emphasize other problems. In
particular data sources such as Twitter are not representative of the
overall population, and results drawn from such sources may then lead to
wrong conclusions. Google Translate—which
is based on big data statistical analysis of text—does a good job at
translating web pages. However, results from specialized domains may be
dramatically skewed.
On the other hand, big data may also introduce new problems, such as the
multiple comparisons problem: simultaneously testing a large set of hypotheses is likely to produce many false results that mistakenly appear significant.
Ioannidis argued that "most published research findings are false"
due to essentially the same effect: when many scientific teams and
researchers each perform many experiments (i.e. process a big amount of
scientific data; although not with big data technology), the likelihood
of a "significant" result being false grows fast – even more so, when
only positive results are published.
Furthermore, big data analytics results are only as good as the model on
which they are predicated. In an example, big data took part in
attempting to predict the results of the 2016 U.S. Presidential Election with varying degrees of success.