A prediction (
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''præ-'', "before," and ''dicere'', "to say"), or
forecast, is a statement about a future
event
Event may refer to:
Gatherings of people
* Ceremony, an event of ritual significance, performed on a special occasion
* Convention (meeting), a gathering of individuals engaged in some common interest
* Event management, the organization of e ...
or data. They are often, but not always, based upon experience or knowledge. There is no universal agreement about the exact difference from "
estimation
Estimation (or estimating) is the process of finding an estimate or approximation, which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable. The value is nonetheless usable because it is der ...
"; different authors and disciplines ascribe different
connotation
A connotation is a commonly understood cultural or emotional association that any given word or phrase carries, in addition to its explicit or literal meaning, which is its denotation.
A connotation is frequently described as either positive o ...
s.
Future events are necessarily
uncertain, so guaranteed accurate information about the future is impossible. Prediction can be useful to assist in making
plans
A plan is typically any diagram or list of steps with details of timing and resources, used to achieve an objective to do something. It is commonly understood as a temporal set of intended actions through which one expects to achieve a goal.
...
about possible developments.
Opinion
In a non-statistical sense, the term "prediction" is often used to refer to an
informed guess or opinion.
A prediction of this kind might be informed by a predicting person's
abductive reasoning
Abductive reasoning (also called abduction,For example: abductive inference, or retroduction) is a form of logical inference formulated and advanced by American philosopher Charles Sanders Peirce beginning in the last third of the 19th century ...
,
inductive reasoning
Inductive reasoning is a method of reasoning in which a general principle is derived from a body of observations. It consists of making broad generalizations based on specific observations. Inductive reasoning is distinct from ''deductive'' re ...
,
deductive reasoning
Deductive reasoning is the mental process of drawing deductive inferences. An inference is deductively valid if its conclusion follows logically from its premises, i.e. if it is impossible for the premises to be true and the conclusion to be fals ...
, and
experience
Experience refers to conscious events in general, more specifically to perceptions, or to the practical knowledge and familiarity that is produced by these conscious processes. Understood as a conscious event in the widest sense, experience involv ...
; and may be useful—if the predicting person is a
knowledgeable person in the field.
The
Delphi method }
The Delphi method or Delphi technique ( ; also known as Estimate-Talk-Estimate or ETE) is a structured communication technique or method, originally developed as a systematic, interactive forecasting method which relies on a panel of experts. The ...
is a technique for eliciting such expert-judgement-based predictions in a controlled way. This type of prediction might be perceived as consistent with statistical techniques in the sense that, at minimum, the "data" being used is the predicting expert's
cognitive experiences forming an
intuitive
Intuition is the ability to acquire knowledge without recourse to conscious reasoning. Different fields use the word "intuition" in very different ways, including but not limited to: direct access to unconscious knowledge; unconscious cognition; ...
"probability curve."
Statistics
In
statistics
Statistics (from German language, German: ''wikt:Statistik#German, Statistik'', "description of a State (polity), state, a country") is the discipline that concerns the collection, organization, analysis, interpretation, and presentation of ...
, prediction is a part of
statistical inference
Statistical inference is the process of using data analysis to infer properties of an underlying probability distribution, distribution of probability.Upton, G., Cook, I. (2008) ''Oxford Dictionary of Statistics'', OUP. . Inferential statistical ...
. One particular approach to such inference is known as
predictive inference
Statistical inference is the process of using data analysis to infer properties of an underlying distribution of probability.Upton, G., Cook, I. (2008) ''Oxford Dictionary of Statistics'', OUP. . Inferential statistical analysis infers propertie ...
, but the prediction can be undertaken within any of the several approaches to statistical inference. Indeed, one possible description of statistics is that it provides a means of transferring knowledge about a sample of a population to the whole population, and to other related populations, which is not necessarily the same as prediction over time. When information is transferred across time, often to specific points in time, the process is known as
forecasting
Forecasting is the process of making predictions based on past and present data. Later these can be compared (resolved) against what happens. For example, a company might estimate their revenue in the next year, then compare it against the actual ...
. Forecasting usually requires
time series
In mathematics, a time series is a series of data points indexed (or listed or graphed) in time order. Most commonly, a time series is a sequence taken at successive equally spaced points in time. Thus it is a sequence of discrete-time data. Exa ...
methods, while prediction is often performed on
cross-sectional data
Cross-sectional data, or a cross section of a study population, in statistics and econometrics, is a type of data collected by observing many subjects (such as individuals, firms, countries, or regions) at the one point or period of time. The analy ...
.
Statistical techniques used for prediction include
regression analysis
In statistical modeling, regression analysis is a set of statistical processes for estimating the relationships between a dependent variable (often called the 'outcome' or 'response' variable, or a 'label' in machine learning parlance) and one ...
and its various sub-categories such as
linear regression
In statistics, linear regression is a linear approach for modelling the relationship between a scalar response and one or more explanatory variables (also known as dependent and independent variables). The case of one explanatory variable is call ...
,
generalized linear model
In statistics, a generalized linear model (GLM) is a flexible generalization of ordinary linear regression. The GLM generalizes linear regression by allowing the linear model to be related to the response variable via a ''link function'' and b ...
s (
logistic regression
In statistics, the logistic model (or logit model) is a statistical model that models the probability of an event taking place by having the log-odds for the event be a linear function (calculus), linear combination of one or more independent var ...
,
Poisson regression
In statistics, Poisson regression is a generalized linear model form of regression analysis used to model count data and contingency tables. Poisson regression assumes the response variable ''Y'' has a Poisson distribution, and assumes the logari ...
,
Probit regression
In statistics, a probit model is a type of regression where the dependent variable can take only two values, for example married or not married. The word is a portmanteau, coming from ''probability'' + ''unit''. The purpose of the model is to est ...
), etc. In case of forecasting,
autoregressive moving average model
In statistics, econometrics and signal processing, an autoregressive (AR) model is a representation of a type of random process; as such, it is used to describe certain time-varying processes in nature, economics, etc. The autoregressive model spe ...
s and
vector autoregression
Vector autoregression (VAR) is a statistical model used to capture the relationship between multiple quantities as they change over time. VAR is a type of stochastic process model. VAR models generalize the single-variable (univariate) autoregres ...
models can be utilized. When these and/or related, generalized set of regression or
machine learning
Machine learning (ML) is a field of inquiry devoted to understanding and building methods that 'learn', that is, methods that leverage data to improve performance on some set of tasks. It is seen as a part of artificial intelligence.
Machine ...
methods are deployed in commercial usage, the field is known as
predictive analytics
Predictive analytics encompasses a variety of statistical techniques from data mining, predictive modeling, and machine learning that analyze current and historical facts to make predictions about future or otherwise unknown events.
In business ...
.
In many applications, such as time series analysis, it is possible to estimate the models that generate the observations. If models can be expressed as
transfer function
In engineering, a transfer function (also known as system function or network function) of a system, sub-system, or component is a function (mathematics), mathematical function that mathematical model, theoretically models the system's output for ...
s or in terms of state-space parameters then smoothed, filtered and predicted data estimates can be calculated. If the underlying generating models are linear then a minimum-variance
Kalman filter
For statistics and control theory, Kalman filtering, also known as linear quadratic estimation (LQE), is an algorithm that uses a series of measurements observed over time, including statistical noise and other inaccuracies, and produces estimat ...
and a minimum-variance smoother may be used to recover data of interest from noisy measurements. These techniques rely on one-step-ahead predictors (which minimise the variance of the
prediction error
In statistics the mean squared prediction error or mean squared error of the predictions of a smoothing or curve fitting procedure is the expected value of the squared difference between the fitted values implied by the predictive function \wideh ...
). When the generating models are nonlinear then stepwise linearizations may be applied within
Extended Kalman Filter
In estimation theory, the extended Kalman filter (EKF) is the nonlinear version of the Kalman filter which linearizes about an estimate of the current mean and covariance. In the case of well defined transition models, the EKF has been considered t ...
and smoother recursions. However, in nonlinear cases, optimum minimum-variance performance guarantees no longer apply.
To use regression analysis for prediction, data are collected on the variable that is to be predicted, called the
dependent variable
Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences. Dependent variables receive this name because, in an experiment, their values are studied under the supposition or demand ...
or response variable, and on one or more variables whose values are
hypothesized to influence it, called
independent variable
Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences. Dependent variables receive this name because, in an experiment, their values are studied under the supposition or demand ...
s or explanatory variables. A
functional form, often linear, is hypothesized for the postulated causal relationship, and the
parameter
A parameter (), generally, is any characteristic that can help in defining or classifying a particular system (meaning an event, project, object, situation, etc.). That is, a parameter is an element of a system that is useful, or critical, when ...
s of the function are
estimated
Estimation (or estimating) is the process of finding an estimate or approximation, which is a value that is usable for some purpose even if input data may be incomplete, uncertain, or unstable. The value is nonetheless usable because it is der ...
from the data—that is, are chosen so as to optimize is some way the
fit of the function, thus parameterized, to the data. That is the estimation step. For the prediction step, explanatory variable values that are deemed relevant to future (or current but not yet observed) values of the dependent variable are input to the parameterized function to generate predictions for the dependent variable.
Science
In science, a prediction is a rigorous, often quantitative, statement, forecasting what would be observed under specific conditions; for example, according to theories of
gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
, if an apple fell from a tree it would be seen to move towards the center of the earth with a specified and constant
acceleration
In mechanics, acceleration is the rate of change of the velocity of an object with respect to time. Accelerations are vector quantities (in that they have magnitude and direction). The orientation of an object's acceleration is given by the ...
. The
scientific method
The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific m ...
is built on testing statements that are
logical consequence
Logical consequence (also entailment) is a fundamental concept in logic, which describes the relationship between statements that hold true when one statement logically ''follows from'' one or more statements. A valid logical argument is on ...
s of scientific theories. This is done through repeatable
experiment
An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into Causality, cause-and-effect by demonstrating what outcome oc ...
s or observational studies.
A
scientific theory
A scientific theory is an explanation of an aspect of the natural world and universe that has been repeatedly tested and corroborated in accordance with the scientific method, using accepted protocols of observation, measurement, and evaluatio ...
whose predictions are contradicted by observations and evidence will be rejected. New theories that generate many new predictions can more easily be supported or
falsified
Falsifiability is a standard of evaluation of scientific theories and hypotheses that was introduced by the philosopher of science Karl Popper in his book ''The Logic of Scientific Discovery'' (1934). He proposed it as the cornerstone of a sol ...
(see
predictive power
The concept of predictive power, the power of a scientific theory to generate testable predictions, differs from ''explanatory power'' and ''descriptive power'' (where phenomena that are already known are retrospectively explained or described ...
). Notions that make no ''
testable
Testability is a primary aspect of Science and the Scientific Method and is a property applying to an empirical hypothesis, involves two components:
#Falsifiability or defeasibility, which means that counterexamples to the hypothesis are logicall ...
'' predictions are usually considered not to be part of science (
protoscience
__NOTOC__
In the philosophy of science, there are several definitions of protoscience. Its simplest meaning (most closely reflecting its roots of '' proto-'' + ''science'') involves the earliest eras of the history of science, when the scientific m ...
or
nescience) until testable predictions can be made.
Mathematical equation
In mathematics, an equation is a formula that expresses the equality of two expressions, by connecting them with the equals sign . The word ''equation'' and its cognates in other languages may have subtly different meanings; for example, in F ...
s and
models
A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin ''modulus'', a measure.
Models c ...
, and
computer model
Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be deter ...
s, are frequently used to describe the past and future behaviour of a process within the boundaries of that model. In some cases the
probability
Probability is the branch of mathematics concerning numerical descriptions of how likely an Event (probability theory), event is to occur, or how likely it is that a proposition is true. The probability of an event is a number between 0 and ...
of an outcome, rather than a specific outcome, can be predicted, for example in much of
quantum physics
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, qua ...
.
In
microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circu ...
s,
branch prediction
In computer architecture, a branch predictor is a digital circuit that tries to guess which way a branch (e.g., an if–then–else structure) will go before this is known definitively. The purpose of the branch predictor is to improve the flow ...
permits avoidance of
pipeline
Pipeline may refer to:
Electronics, computers and computing
* Pipeline (computing), a chain of data-processing stages or a CPU optimization found on
** Instruction pipelining, a technique for implementing instruction-level parallelism within a s ...
emptying at
branch instructions.
In
engineering
Engineering is the use of scientific method, scientific principles to design and build machines, structures, and other items, including bridges, tunnels, roads, vehicles, and buildings. The discipline of engineering encompasses a broad rang ...
, possible
failure mode
Failure causes are defects in design, process, quality, or part application, which are the underlying cause of a failure or which initiate a process which leads to failure. Where failure depends on the user of the product or process, then human er ...
s are predicted and avoided by correcting the
failure mechanism
Failure causes are defects in design, process, quality, or part application, which are the underlying cause of a failure or which initiate a process which leads to failure. Where failure depends on the user of the product or process, then human er ...
causing the failure.
Accurate prediction and forecasting are very difficult in some areas, such as
natural disasters
A natural disaster is "the negative impact following an actual occurrence of natural hazard in the event that it significantly harms a community". A natural disaster can cause loss of life or damage property, and typically leaves some econo ...
,
pandemics
A pandemic () is an epidemic of an infectious disease that has spread across a large region, for instance multiple continents or worldwide, affecting a substantial number of individuals. A widespread endemic disease with a stable number of in ...
,
demography
Demography () is the statistics, statistical study of populations, especially human beings.
Demographic analysis examines and measures the dimensions and Population dynamics, dynamics of populations; it can cover whole societies or groups ...
,
population dynamics
Population dynamics is the type of mathematics used to model and study the size and age composition of populations as dynamical systems.
History
Population dynamics has traditionally been the dominant branch of mathematical biology, which has ...
and
meteorology
Meteorology is a branch of the atmospheric sciences (which include atmospheric chemistry and physics) with a major focus on weather forecasting. The study of meteorology dates back millennia, though significant progress in meteorology did not ...
. For example, it is possible to predict the occurrence of
solar cycle
The solar cycle, also known as the solar magnetic activity cycle, sunspot cycle, or Schwabe cycle, is a nearly periodic 11-year change in the Sun's activity measured in terms of variations in the number of observed sunspots on the Sun's surfa ...
s, but their exact timing and magnitude is much more difficult (see picture to right).
In materials engineering it is also possible to predict the life time of a material with a mathematical model.
Hypothesis
Established science makes useful predictions which are often extremely reliable and accurate; for example,
eclipse
An eclipse is an astronomical event that occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three ce ...
s are routinely predicted.
New theories make predictions which allow them to be disproved by reality. For example, predicting the structure of crystals at the atomic level is a current research challenge. In the early 20th century the scientific consensus was that there existed an absolute
frame of reference
In physics and astronomy, a frame of reference (or reference frame) is an abstract coordinate system whose origin, orientation, and scale are specified by a set of reference points― geometric points whose position is identified both mathema ...
, which was given the name ''
luminiferous ether
Luminiferous aether or ether ("luminiferous", meaning "light-bearing") was the postulated Transmission medium, medium for the propagation of light. It was invoked to explain the ability of the apparently wave-based light to propagate through empty ...
''. The existence of this absolute frame was deemed necessary for consistency with the established idea that the speed of light is constant. The famous
Michelson–Morley experiment
The Michelson–Morley experiment was an attempt to detect the existence of the luminiferous aether, a supposed medium permeating space that was thought to be the carrier of light waves. The experiment was performed between April and July 1887 ...
demonstrated that predictions deduced from this concept were not borne out in reality, thus disproving the theory of an absolute frame of reference. The
special theory of relativity
In physics, the special theory of relativity, or special relativity for short, is a scientific theory regarding the relationship between Spacetime, space and time. In Albert Einstein's original treatment, the theory is based on two Postulates of ...
was proposed by Einstein as an explanation for the seeming inconsistency between the constancy of the speed of light and the non-existence of a special, preferred or absolute frame of reference.
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...
's theory of
general relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...
could not easily be tested as it did not produce any effects observable on a terrestrial scale. However, as one of the first
tests of general relativity
Tests of general relativity serve to establish observational evidence for the theory of general relativity. The first three tests, proposed by Albert Einstein in 1915, concerned the "anomalous" precession of the perihelion of Mercury, the ben ...
, the theory predicted that large masses such as
star
A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...
s would bend light, in contradiction to accepted theory; this was observed in a 1919 eclipse.
Finance
Mathematical models of
stock market
A stock market, equity market, or share market is the aggregation of buyers and sellers of stocks (also called shares), which represent ownership claims on businesses; these may include ''securities'' listed on a public stock exchange, as ...
behaviour (and economic behaviour in general) are also unreliable in predicting future behaviour. Among other reasons, this is because economic events may span several years, and the world is changing over a similar time frame, thus invalidating the relevance of past observations to the present. Thus there are an extremely small number (of the order of 1) of relevant past data points from which to project the future. In addition, it is generally believed that stock market prices already take into account all the information available to predict the future, and subsequent movements must therefore be the result of unforeseen events. Consequently, it is extremely difficult for a
stock investor
A stock trader or equity trader or share trader, also called a stock investor, is a person or company involved in trading equity securities and attempting to profit from the purchase and sale of those securities. Stock traders may be an invest ...
to
anticipate or predict a
stock market boom, or a
stock market crash
A stock market crash is a sudden dramatic decline of stock
In finance, stock (also capital stock) consists of all the shares by which ownership of a corporation or company is divided.Longman Business English Dictionary: "stock - ''especia ...
. In contrast to predicting the actual stock return, forecasting of broad
economic trend
*all the economic indicators that are the subject of economic forecasting
**see also: econometrics
*general trends in the economy, see: economic history.
*general trends in the academic field of economics, see: history of economics
History ...
s tends to have better accuracy. Such analysis is provided by both non-profit groups as well as by for-profit private institutions.
Some correlation has been seen between actual stock market movements and prediction data from large groups in surveys and prediction games.
An
actuary
An actuary is a business professional who deals with the measurement and management of risk and uncertainty. The name of the corresponding field is actuarial science. These risks can affect both sides of the balance sheet and require asset man ...
uses
actuarial science to assess and predict future business
risk
In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with respect to something that humans value (such as health, well-being, wealth, property or the environme ...
, such that the risk(s) can be
mitigated. For example, in
insurance
Insurance is a means of protection from financial loss in which, in exchange for a fee, a party agrees to compensate another party in the event of a certain loss, damage, or injury. It is a form of risk management, primarily used to hedge ...
an actuary would use a
life table
In actuarial science and demography, a life table (also called a mortality table or actuarial table) is a table which shows, for each age, what the probability is that a person of that age will die before their next birthday ("probability of deat ...
(which incorporates the historical experience of mortality rates and sometimes an estimate of future trends) to project
life expectancy
Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, current age, and other demographic factors like sex. The most commonly used measure is life expectancy at birth ...
.
Sports
Predicting the outcome of sporting events is a business which has grown in popularity in recent years. Handicappers predict the outcome of games using a variety of mathematical formulas, simulation models or
qualitative analysis. Early, well known sports bettors, such as
Jimmy the Greek
James George Snyder Sr. (born Dimetrios Georgios Synodinos Roberto Kurtz, September 9, 1918 – April 21, 1996), better known as Jimmy the Greek, was an American sports commentator and Las Vegas bookmaker. A regular contributor to the CBS prog ...
, were believed to have access to information that gave them an edge. Information ranged from personal issues, such as gambling or drinking to undisclosed injuries; anything that may affect the performance of a player on the field.
Recent times have changed the way sports are predicted. Predictions now typically consist of two distinct approaches: Situational plays and statistical based models. Situational plays are much more difficult to measure because they usually involve the motivation of a team. Dan Gordon, noted handicapper, wrote "Without an emotional edge in a game in addition to value in a line, I won't put my money on it". These types of plays consist of: Betting on the home underdog, betting against Monday Night winners if they are a favorite next week, betting the underdog in "look ahead" games etc. As situational plays become more widely known they become less useful because they will impact the way the line is set.
The widespread use of technology has brought with it more modern
sports betting systems
Sports betting systems are sets of events that when combined for a particular game for a particular sport represent a profitable betting scenario. Since sports betting involves humans, there is no deterministic edge to the house or the gambler. Sys ...
. These systems are typically algorithms and simulation models based on
regression analysis
In statistical modeling, regression analysis is a set of statistical processes for estimating the relationships between a dependent variable (often called the 'outcome' or 'response' variable, or a 'label' in machine learning parlance) and one ...
.
Jeff Sagarin
Jeff Sagarin is an American sports statistician known for his development of a method for ranking and rating sports teams in a variety of sports. His ratings have been a regular feature in the ''USA Today'' sports section since 1985, have been use ...
, a sports statistician, has brought attention to sports by having the results of his models published in USA Today. He is currently paid as a consultant by the
Dallas Mavericks
The Dallas Mavericks (often referred to as the Mavs) are an American professional basketball team based in Dallas. The Mavericks compete in the National Basketball Association (NBA) as a member of the Western Conference (NBA), Western Conferenc ...
for his advice on lineups and the use of his Winval system, which evaluates free agents.
Brian Burke, a former
Navy
A navy, naval force, or maritime force is the branch of a nation's armed forces principally designated for naval warfare, naval and amphibious warfare; namely, lake-borne, riverine, littoral zone, littoral, or ocean-borne combat operations and ...
fighter pilot turned sports statistician, has published his results of using regression analysis to predict the outcome of NFL games.
Ken Pomeroy
Ken Pomeroy is the creator of the college basketball website and statistical archive KenPom. His website includes his College Basketball Ratings, statistics for every NCAA men's Division I basketball team, with archives dating back to the 2002 s ...
is widely accepted as a leading authority on college basketball statistics. His website includes his College Basketball Ratings, a tempo based statistics system. Some statisticians have become very famous for having successful prediction systems. Dare wrote "the effective odds for sports betting and horse racing are a direct result of human decisions and can therefore potentially exhibit consistent error". Unlike other games offered in a casino, prediction in sporting events can be both logical and consistent.
Other more advance models include those based on Bayesian networks, which are causal probabilistic models commonly used for risk analysis and decision support. Based on this kind of mathematical modelling, Constantinou et al., have developed models for predicting the outcome of association football matches. What makes these models interesting is that, apart from taking into consideration relevant historical data, they also incorporate all these vague subjective factors, like availability of key players, team fatigue, team motivation and so on. They provide the user with the ability to include their best guesses about things that there are no hard facts available. This additional information is then combined with historical facts to provide a revised prediction for future match outcomes. The initial results based on these modelling practices are encouraging since they have demonstrated consistent profitability against published market odds.
Nowadays sport betting is a huge business; there are many websites (systems) alongside betting sites, which give tips or predictions for future games. Some of these prediction websites (tipsters) are based on human predictions, but others on computer software sometimes called prediction robots or bots. Prediction bots can use different amount of data and algorithms and because of that their accuracy may vary.
Sites such a
Tzefi.commaintain that other sites' claim that they simulate the game 50,000 times before it's actually played on the field, is quite misleading and incorrect.
This is due to the fact that those sites don't consider the human element of the game, and that a
batter with a .330
ERA
An era is a span of time defined for the purposes of chronology or historiography, as in the regnal eras in the history of a given monarchy, a calendar era used for a given calendar, or the geological eras defined for the history of Earth.
Comp ...
may
strike out
In baseball or softball, a strikeout (or strike-out) occurs when a batter accumulates three strikes during a time at bat. It usually means that the batter is out. A strikeout is a statistic recorded for both pitchers and batters, and is denot ...
when the bases are loaded, or a
quarterback
The quarterback (commonly abbreviated "QB"), colloquially known as the "signal caller", is a position in gridiron football. Quarterbacks are members of the offensive platoon and mostly line up directly behind the offensive line. In modern Ame ...
with a 100+
passer rating
Passer rating (also known as passing efficiency in college football) is a measure of the performance of passers, primarily quarterbacks, in gridiron football. There are two formulas currently in use: one used by both the National Football Leag ...
may throw an
interception
In ball-playing competitive team sports, an interception or pick is a move by a player involving a pass of the ball—whether by foot or hand, depending on the rules of the sport—in which the ball is intended for a player of the same team b ...
at a crucial time.
Tzefi.com boasts a 64.5% accuracy in predicting NFL games.
Social science
Prediction in the non-economic social sciences differs from the natural sciences and includes multiple alternative methods such as trend projection, forecasting, scenario-building and Delphi surveys. The oil company Shell is particularly well known for its scenario-building activities.
One reason for the peculiarity of societal prediction is that in the social sciences, "predictors are part of the social context about which they are trying to make a prediction and may influence that context in the process".
As a consequence, societal predictions can become self-destructing. For example, a forecast that a large percentage of a population will become HIV infected based on existing trends may cause more people to avoid risky behavior and thus reduce the HIV infection rate, invalidating the forecast (which might have remained correct if it had not been publicly known). Or, a prediction that cybersecurity will become a major issue may cause organizations to implement more security cybersecurity measures, thus limiting the issue.
In
politics
Politics (from , ) is the set of activities that are associated with making decisions in groups, or other forms of power relations among individuals, such as the distribution of resources or status. The branch of social science that studies ...
it is common to attempt to predict the outcome of
elections
An election is a formal group decision-making process by which a population chooses an individual or multiple individuals to hold public office.
Elections have been the usual mechanism by which modern representative democracy has operate ...
via political forecasting techniques (or assess the popularity of politicians) through the use of opinion polls. Prediction games have been used by many corporations and governments to learn about the most likely outcome of future events.
Prophecy
Predictions have often been made, from antiquity until the present, by using paranormal or supernatural means such as prophecy or by observing omens. Methods including water divining, astrology, numerology, fortune telling, Oneiromancy, interpretation of dreams, and many other forms of divination, have been used for millennia to attempt to predict the future. These means of prediction have not been proven by scientific experiments.
In literature, vision and prophecy are literary devices used to present a possible timeline of future events. They can be distinguished by vision referring to what an individual sees happen. The book of Revelation, in the New Testament, thus uses vision as a literary device in this regard. It is also prophecy or prophetic literature when it is related by an individual in a sermon or other public forum.
Divination is the attempt to gain insight into a question or situation by way of an occultic standardized process or ritual. It is an integral part of witchcraft and has been used in various forms for thousands of years. Diviners ascertain their interpretations of how a querent should proceed by reading signs, events, or omens, or through alleged contact with a supernatural agency, most often describe as an angel or a god though viewed by Christians and Jews as a fallen angel or demon.
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Fiction
Fiction (especially fantasy, future history, forecasting and science fiction) often features instances of prediction achieved by unconventional means.
In fantasy literature, predictions are often obtained through magic (paranormal), magic or prophecy, sometimes referring back to old traditions. For example, in J. R. R. Tolkien's ''The Lord of the Rings'', many of the characters possess an awareness of events extending into the future, sometimes as prophecies, sometimes as more-or-less vague 'feelings'. The character Galadriel, in addition, employs a water "mirror" to show images, sometimes of possible future events.
In some of Philip K. Dick's stories, mutant humans called ''precogs'' can foresee the future (ranging from days to years). In the story called ''The Golden Man'', an exceptional mutant can predict the future to an indefinite range (presumably up to his death), and thus becomes completely non-human, an animal that follows the predicted paths automatically. Precogs also play an essential role in another of Dick's stories, ''The Minority Report'', which was turned into a Minority Report (film), film by Steven Spielberg in 2002.
In the ''Foundation series, Foundation'' series by Isaac Asimov, a mathematician finds out that historical events (up to some detail) can be theoretically modelled using equations, and then spends years trying to put the theory in practice. The new science of Psychohistory (fictional), psychohistory founded upon his success can simulate history and extrapolate the present into the future.
In Frank Herbert's sequels to 1965's ''Dune (novel), Dune'', his characters are dealing with the repercussions of being able to see the possible futures and select amongst them. Herbert sees this as a trap of stagnation, and his characters follow a so-called "Golden Path (Dune), Golden Path" out of the trap.
In Ursula K. Le Guin's ''The Left Hand of Darkness'', the humanoid inhabitants of planet Gethen have mastered the art of prophecy and routinely produce data on past, present or future events on request. In this story, this was a minor plot device.
Poetry
For the ancients, prediction, prophesy, and poetry were often intertwined. Prophecies were given in verse, and a word for poet in Latin is “vates” or prophet. Both poets and prophets claimed to be inspired by forces outside themselves. In contemporary cultures, theological revelation and poetry are typically seen as distinct and often even as opposed to each other. Yet the two still are often understood together as symbiotic in their origins, aims, and purposes.
See also
* Expectation (epistemic), Expectation
* Forecasting
* Famous predictions
* Futures studies
* Omen
* Oracle
* Predictability
* Prediction market
* Predictive medicine
* Predictive modelling
* Prognosis
* Prognostics
* Reference class forecasting
* Regression analysis
* Thought experiment
* Trend estimation
Footnotes
Further reading
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{{Wikiquote
Prediction,
Scientific method