The previous post “Random Numbers Predict Future Temperatures” used random numbers for prediction of climate. Random numbers may also be predicted. This is a major difference between models and natural phenomena. Random numbers generated by computer can always be predicted exactly given knowledge of the code, and so have a deterministic generating mechanism, or model.

The above series of numbers appears to be a temperature trend such as 20th century warming, composed of random fluctuations with a slight upward trend. One might find on fitting a linear regression the coefficients are significant, and then use the model to predict the trend in upward temperatures to continue.

It is actually possible to predict all subsequent numbers in the series exactly with the following deterministic code for generating pseudo-random numbers in R.

dkrand< -function(n) { x<-1:n q<-1:n+1 q[1] <-1426594706 k<-7^5 m<-2^31-1 for (i in x) { q[i+1]<- (k * q[i]) %% m x [i]<- q[i+1]/ m } return(x) }

This examples shows you should be very concerned if you find a paper in which the authors use a model building technique such as regression and then use it for prediction, treating the resulting models and coefficients as though the model were true.

The confusion is very well described in the essay by Gerard Dallal “The Most Important Lesson You’ll Ever Learn About Multiple Linear Regression Analysis“.

It is well-stated by Chris Chatfield 1995.

It is “well known” to be “logically unsound and practically misleading” to make inference as if a model is known to be true when it has, in fact, been selected from the same data to be used for estimation purposes.

## References

Chris Chatfield in “Model Uncertainty, Data Mining and Statistical Inference”, Journal of the Royal Statistical Society, Series A, 158 (1995), 419-486 (p 421).

Pingback: friv games

Pingback: rooms for rent Los Angeles

Pingback: angry birds game

Pingback: sam waltonman

Pingback: middlesex county nj divorce lawyers goldstein, bachman and newman

Pingback: locksmith finder

Pingback: andreus s.r.o

Pingback: locksmith in houston texas

Pingback: pre employment background check

Pingback: somanabolic muscle maximizer

Pingback: iherb coupon

Pingback: iherb promo code

Pingback: clik here for more info

Pingback: best job in nyc

Pingback: Fun Games Online

Pingback: Blog

Pingback: buy cialis

Pingback: sex on cams

Pingback: Seo

Pingback: Empowering

Pingback: Technology

Pingback: Solutions

Pingback: pro camera dealer

Pingback: Tech

Pingback: Austin divorce lawyer

Pingback: hacker

Pingback: google

Pingback: informative post

Pingback: Affidavit for first child?

Pingback: Throne Rush Gems free

Pingback: Start

Pingback: escritorio de advocacia

Pingback: Top mediums van parastars voor duidelijk advies

Pingback: Health

Pingback: Finance

Pingback: rebelmouse.com/somanabolicmusclemaximizerrr

Pingback: Liberty

Pingback: capture his heart review

Pingback: royal revolt 2 hack

Pingback: hairy anus

Pingback: iherb coupon code

Pingback: Trading

Pingback: nyc

Pingback: buy congo gold from outside the bank

Pingback: Websiteoptimalisatie/klikhier/websiteoptimalisatie

Pingback: Helderzienden online: Live helderziende - Heldervoelende helderziende

Pingback: Business

Pingback: iherb coupon codes

Pingback: workout obsession

Pingback: iherb coupons

Pingback: iherb coupon codes

Pingback: iherb coupon

Pingback: iherb coupons

Pingback: mark cobb

Pingback: contract lawyer dallas

Pingback: where can i buy a ninja blender

Pingback: product number free

Pingback: Technology

Pingback: clash of clans hack

Pingback: School

Pingback: Process Servers in Chicago, IL

Pingback: abstract painting

Pingback: Diindolylmethane

Pingback: Fashion

Pingback: low cost weltenbummler sonderreport

Pingback: water ionizer comparison

Pingback: led bulbs

Pingback: 500 twitter followers for $5

Pingback: mt4 script

Pingback: download

Pingback: click here

Pingback: book of ra deluxe

Pingback: ppi claims

Pingback: paleo recipe book review

Pingback: kratom

Pingback: full report

Pingback: dallas roofing repair

Pingback: Prywatne pokoje

Pingback: homeowners insurance quotes

Pingback: Pest Control Lithonia

Pingback: method

Pingback: Sarasota SEO Company

Pingback: Get Free Facebook Likes

Pingback: Movemynt Products

Pingback: LINK M88

Pingback: affordable life insurance rate

Pingback: hHmes For Sale Downers Grove IL

Pingback: vitamin c serum for face

Pingback: geo news tv live hd

Pingback: duct cleaning houton

Pingback: Illinois Discount Realtor

Pingback: reviews for garcinia cambogia extract

Pingback: häuser zum kaufen

Pingback: muscle gaining secrets transformation

Pingback: secret money system review

Pingback: seizure forum

Pingback: metodo ritmo calculadora

Pingback: bhw

Pingback: People Development Africa

Pingback: inks

Pingback: fort worth

Pingback: clash of clans hack

Pingback: clash of clans cheats

Pingback: gay celebrities in hollywood

Pingback: Party Shop

Pingback: Auto insurance quotes comparison online

Pingback: baby learning

Pingback: Best dentist in Cambridge

Pingback: massage therapy ceu online

Pingback: hebdomadaire

Pingback: berita hari ini

Pingback: fastest weight loss

Pingback: jedynie bliski posrednik

Pingback: www.legacyfoodstorage.com

Pingback: rolety zewnetrzne

Pingback: Amddram

Pingback: laptop backpack

Pingback: swimming classes for toddlers in orlando

Pingback: Buy Cheap Lingerie UK

Pingback: paleo recipe book review

Pingback: grow box

Pingback: hefalimp cardijon

Pingback: Wp Weekend Phoenix

Pingback: thiet ke web ban hang

Pingback: Green tea

Pingback: this site has good information

Pingback: Jewellery

Pingback: gamesgames

Pingback: cinch diet

Pingback: fajsdgjfashdjfaksjdhkfa