What is Forecast: Definition and 19 Discussions

Forecasting is the process of making predictions based on past and present data and most commonly by analysis of trends. A commonplace example might be estimation of some variable of interest at some specified future date. Prediction is a similar, but more general term. Both might refer to formal statistical methods employing time series, cross-sectional or longitudinal data, or alternatively to less formal judgmental methods. Usage can differ between areas of application: for example, in hydrology the terms "forecast" and "forecasting" are sometimes reserved for estimates of values at certain specific future times, while the term "prediction" is used for more general estimates, such as the number of times floods will occur over a long period.
Risk and uncertainty are central to forecasting and prediction; it is generally considered good practice to indicate the degree of uncertainty attaching to forecasts. In any case, the data must be up to date in order for the forecast to be as accurate as possible. In some cases the data used to predict the variable of interest is itself forecast.

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  1. P

    I Quantum Mechanics as a Probabilistic forecast of reality

    Is Quantum Mechanics a Probabilistic Forecast of nature?Someone I know told me their interpretation of QM is that QM only a probabilistic forecast of systems like electrons around atoms. I would like someone to analyse this interpretation and say if its valid or not. According to this person we...
  2. F

    A Force to fix sigma8 or A_s for Forecasts

    Hello, in the context of Forecasts with Fisher's formalism, I make vary cosmological parameters to compute the elements of the Fisher matrix. First, I generate with CAMB code a linear power spectrum. Then, from this, I am computing ##\sigma_{8,\text{linear}}##. Secondly, Before relaunching...
  3. F

    I What do "marginalized" or "marginalized error" mean? (contours - posterior)

    I am curently working on Forecast in cosmology and I didn't grasp very well different details. Forecast allows, wiht Fisher's formalism, to compute constraints on cosmological parameters. I have 2 issues of understanding : 1) Here below a table containing all errors estimated on these...
  4. F

    A Forecast with Fisher formalism : loss or gain of information

    In the context of a forecast, I am currently working on Fisher's formalism which is part of a more general theory, that of information. My problem applies to estimating cosmological parameters from input data with the Fisher formalism and recipes to build a Fisher matrix. The context is...
  5. S

    A Reasonable length of forecast horizon in a time series

    Suppose we have monthly totals of observed data for last 35 years. That data is of inflow of a river in a reservoir and monthly demands from the reservoir. We are interested to check the effect of construction of a dam in the upstream. The effect is, whether the downstream reservoir will have...
  6. W

    Does a weather forecast affect computation of probability of rain?

    Please help with this: Suppose in recent years, it has only rained an average of 5 days a year. The weather forecast, which has an accuracy of 90%, predicts rain for tomorrow. What is the probability of rain tomorrow? A: <1% B: between 5 and 15% C: between 15 and 80% D: between 80 and...
  7. R

    ARMA forecasting - forecast error variance

    Hi I've got an ARMA model, and I am struggling to theoretically quantify the benefit of using it to generate forecasts for various lead times, compared to using the mean level of the process. I think the ratio of variance of forecast error using ARMA to variance of forecast error using the mean...
  8. Greg Bernhardt

    MIT researchers forecast global economic collapse by 2030

    MIT researchers forecast "global economic collapse" by 2030 http://news.yahoo.com/blogs/sideshow/next-great-depression-mit-researchers-predict-global-economic-190352944.htmlAnything we don't already know? Can anyone find the actual study?
  9. N

    What is the probability of a correct rain prediction in this weather forecast?

    The weather is dreadful here. It rains on three times as many days as there are rain-free days. Luckily the daily weather forecast is fairly good. Whether the forecast is for rain or for no rain, it is correct on nine occasions out of ten. What is the probability that the weather forecast...
  10. H

    Technology to forecast earthquakes, volcanic activity

    I know that it's likely impossible to predict exactly when an earthquake will strike or when a volcano will erupt, but I was just wondering what technologies existed out there to at least forecast them and let people know that something is imminent. Again, could remote or wireless sensing...
  11. B

    Mars weather forecast: Clear skies, high of -30

    An article from the Globe and Mail, the 37 million dollar Canadian space station onboard phoenix reports its first weather readings. If your planning on traveling to Mars for a spring getaway I suggest you pack your winter clothing. "Mars weather forecast: Clear skies, high of -30 ANNE...
  12. marcus

    Most important paper: first quarter 2008 forecast poll

    Which of these first quarter 2008 papers/presentations do you expect to contribute most to future research? 1. http://cift.fuw.edu.pl/users/kostecki/zakopane08/rovelli.pdf Looppy & Foammy: at long last, falling in love Carlo Rovelli This is Rovelli's report at the March 2008 Zakopane...
  13. marcus

    What is the current trend in public interest for string theory?

    Informed public interest in scientific research is part of what keeps the enterprise healthy, and merits some attention. As an index of public interest in string, expressed in the book market, I have been tracking the "string Dow" This is the average at noon (mountain time) of the standings of...
  14. marcus

    Topcites Forecast: How Many String Papers Will Get 100+ Citations in 2006?

    It used to be that in any given year a dozen or more recent string papers would get 100+ citations. So we had a forecast poll last year. I guessed that 8 would, but that turned out to be over-optimistic. I forget whose prediction was closest. Oh here, this shows...
  15. Ivan Seeking

    Alvin Toffler's Revolutionary Ideas: Read "Future Forecast" Today!

    Many here may not be familiar with a hero of mine - Alvin Toffler. Toffler is a futurist who is known best for his two books, Future Shock, and The Third Wave, both of which influenced me greatly. In fact to a certain extent it is true that my own business is modeled on "the electronic cottage"...
  16. wolram

    Betting on a Record Cold Winter: What's the Forecast?

    The british press are forcasting a record cold winter, and a major betting company have slashed the odds for this. what are they basing their predictions on ?
  17. marcus

    SelfAdjoint declared winner of first forecast poll

    http://citebase.eprints.org/cgi-bin/citations?id=oai:arXiv.org:hep-th/0507235 sA predicted that Smolin "The Case for Background Independence" would garner 50-69 UK downloads thru end September 2005 that is essentially in the first two full months (aug and sept) that it was posted it would...
  18. marcus

    Forecast String Research Citing in 2005: 11 or More?

    ellipse raised this issue of "string deadend?" or where is string research going. like, is it currently in a slump but will pick up later? or is it going down the tubes, or what? so if you want to, let's put down what we forecast for 2005 and then later, probably early next year when the...
  19. Orion1

    Scientists forecast drastic extinctions

    Scientists forecast drastic extinctions An international group of 19 scientists, analyzing research around the globe, has concluded that a warming climate will rival habitat destruction in prompting widespread extinctions in this century. By 2050, the scientists say, if current warming...