Prediction
[3][failed verification] Forecasting usually requires time series methods, while prediction is often performed on cross-sectional data.
When these and/or related, generalized set of regression or machine learning methods are deployed in commercial usage, the field is known as predictive analytics.
If models can be expressed as transfer functions or in terms of state-space parameters then smoothed, filtered and predicted data estimates can be calculated.
When the generating models are nonlinear then stepwise linearizations may be applied within Extended Kalman Filter and smoother recursions.
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, 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.
Accurate prediction and forecasting are very difficult in some areas, such as natural disasters, pandemics, demography, population dynamics and meteorology.
[7] For example, it is possible to predict the occurrence of solar cycles, but their exact timing and magnitude is much more difficult (see picture to right).
The famous Michelson–Morley experiment demonstrated that predictions deduced from this concept were not borne out in reality, thus disproving the theory of an absolute frame of reference.
Albert Einstein's theory of general relativity could not easily be tested as it did not produce any effects observable on a terrestrial scale.
Individuals who are more susceptible to disease in the future can be offered lifestyle advice or medication with the aim of preventing the predicted illness.
[13][14] A prognosis is made on the basis of the normal course of the diagnosed disease, the individual's physical and mental condition, the available treatments, and additional factors.
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.
Handicappers predict the outcome of games using a variety of mathematical formulas, simulation models or qualitative analysis.
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.
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".
He is currently paid as a consultant by the Dallas Mavericks for his advice on lineups and the use of his Winval system, which evaluates free agents.
Brian Burke, a former Navy fighter pilot turned sports statistician, has published his results of using regression analysis to predict the outcome of NFL games.
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".
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.
Predictions have often been made, from antiquity until the present, by using paranormal or supernatural means such as prophecy or by observing omens.
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'.
In some of Philip K. Dick's stories, mutant humans called precogs can foresee the future (ranging from days to years).
Precogs also play an essential role in another of Dick's stories, The Minority Report, which was turned into a film by Steven Spielberg in 2002.
In the 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.
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.
