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“ I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it ”. Lord William Thomson, 1st Baron Kelvin. Statistics =. “getting meaning from data”. (Michael Starbird ). measures of central values, measures of variation,
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“I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it” Lord William Thomson,1st Baron Kelvin
Statistics = “getting meaningfrom data” (Michael Starbird)
measures of central values, measures of variation, visualization descriptivestatistics “inferential”statistics beatingchance!
“inferential”statistics beatingchance!
“inferential”statistics Population beatingchance! PARAMETERS ESTIMATES Sample inference
But what’s the valueof inferential statisticsin our field?? 1. More explicit theories 2. More constraints on theory 3. (Limited) generalizability
The (twisted) logic of hypothesis testing H0 = there is no difference, or there is no correlation Ha = there is a difference; there is a correlation
The (twisted) logic of hypothesis testing Type I error = behind bars… … but not guilty Type II error = guilty… … but not behind bars
p < 0.05 What doesit really mean?
p < 0.05 = Given that H0 is true,this data would befairly unlikely
One-sample t-test Pairedt-test Unpairedt-test ANOVA Regression DiscrimantFunction Analysis ANCOVA MANOVA χ2 test
One-sample t-test Pairedt-test Unpairedt-test ANOVA Regression DiscrimantFunction Analysis ANCOVA MANOVA χ2 test
General Linear Model
General Linear Model Generalized Linear Model GeneralizedLinearMixed Model
General Linear Model Generalized Linear Model GeneralizedLinearMixed Model
“response” what you measure RT ~ Noise “predictor” what you manipulate
the slope the intercept
The Linear Model response ~ intercept + slope * predictor
The Linear Model Y ~ b0 + b1*X1 coefficients
The Linear Model Y ~ b0 + b1*X1 intercept slope
The Linear Model Y ~ 300 + 9*X1 intercept slope
With Y ~ 300 + 9 *x,what is the response time for anoise level of x = 10? 300 + 9*10 = 390 10 300
“fitted values” Deviation from regression line= residual
The Linear Model Y ~ b0 + b1*X1+ error
The Linear Model Y ~ b0 + b1*X1 + error
is continuous is continuous, too!
men RT ~ Noise women
men RT ~ Noise + Gender women
The Linear Model Y ~ b0 + b1*X1 + b2*X2 noise(continuous) gender(categorical) coefficient ofintercept coefficientsof slopes
The Linear Model “Response” ~ Predictor(s) Can be one thingor many things Has to be onething “multiple regression”
The Linear Model “Response” ~ Predictor(s) Has to becontinuous Can be of any data type (continuous or categorical) (we’ll relaxthat constraint later)
The Linear Model examples RT ~ noise + gender pitch ~ polite vs. informal Word Length ~ Word Frequency
Correlation is (still) not causation Edwards & Lambert (2007); Bohrnstedt& Carter (1971); Duncan(1975); Heise(1969); in Edwards & Lambert (2007)
Correlation is (still) not causation “Response” ~ Predictor(s) Assumed directionof causality