Posts Tagged ‘ stats ’

From one extreme (0) to another (1): challenge failed, but who cares…

January 9, 2011
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From one extreme (0) to another (1): challenge failed, but who cares…

Just after arriving in Montréal, at the beginning of September, I discussed statistics of my blog, and said that it might be possible - or likely - that by new year's Eve, over a million page would have been viewed on my blog (from Google's count...

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Area plots unmasked

December 15, 2010
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Area plots unmasked

RESULTS OF THE GREAT AREA PLOT QUIZ If you are the type of reader who remembers things from last week, you may remember the great area plot quiz we had running. This week, we are excited to announce that the results are in. The plot above shows answers to the four questions. The correct answers

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Using R for Introductory Statistics 3.3

August 11, 2010
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Using R for Introductory Statistics 3.3

...continuing our way though John Verzani's Using R for introductory statistics. Previous installments: chapt1&2, chapt3.1, chapt3.2Relationships in numeric dataIf two data series have a natural pairing (x1,y1),...,(xn,yn), then we can ask, &ld...

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Using R for Introductory Statistics 3.3

August 11, 2010
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Using R for Introductory Statistics 3.3

...continuing our way though John Verzani's Using R for introductory statistics. Previous installments: chapt1&2, chapt3.1, chapt3.2Relationships in numeric dataIf two data series have a natural pairing (x1,y1),...,(xn,yn), then we can ask, &ld...

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Navigate the Bermuda Triangle of Mediation Analysis

July 6, 2010
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Navigate the Bermuda Triangle of Mediation Analysis

MYTHS AND TRUTHS ABOUT AN OFTEN-USED, LITTLE-UNDERSTOOD STATISTICAL PROCEDURE If you go to a consumer research conference, you will hear tales of how experiments have undergone particular statistical rites: the attainment of the elusive crossover interaction, the demonstration of full mediation through Baron and Kenny’s sacred procedure, and so on. DSN has nothing against any

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Maps without map packages

July 1, 2010
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Maps without map packages

LATITUDE + LONGITUDE + OVERPLOTTING FIX = MAPS Decision Science News is always learning stuff from colleague, physicist, mathlete, and all-around computer whiz Jake Hofman. Today, it was a quick and clean way to make nice maps in R without using any map packages: just plot the latitude and longitude of your data points (e.g.

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Entropy augmentation the modulo way

June 29, 2010
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Entropy augmentation the modulo way

Long before I had heard about the connection between entropy and probability theory, I knew about it from the physical sciences. This is most likely how you met it, too. You heard that entropy in the universe is always increasing, and, if you’re like me, that made very little sense. Then you may have heard

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Reaching escape velocity

June 22, 2010
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Reaching escape velocity

Sample once from the Uniform(0,1) distribution. Call the resulting value . Multiply this result by some constant . Repeat the process, this time sampling from Uniform(0, ). What happens when the multiplier is 2? How big does the multiplier have to be to force divergence. Try it and see: iters = 200 locations = rep(0,iters)

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The perfect fake

June 19, 2010
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The perfect fake

Usually when you are doing Monte Carlo testing, you want fake data that’s good, but not too good. You may want a sample taken from the Uniform distribution, but you don’t want your values to be uniformly distributed. In other words, if you were to order your sample values from lowest to highest, you don’t

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A different way to view probability densities

June 12, 2010
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A different way to view probability densities

The standard, textbook way to represent a density function looks like this: Perhaps you have seen this before? (Plot created in R, all source code from this post is included at the end). Not only will you find this plot in statistics books, you’ll also see it in medical texts, sociology, and even economics books.

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