East Carolina University
Department of Psychology
Karl Wuensch's Statistical Help Page
Fair
Use of These Documents

ANOVA, HalfTailed Tests  ANOVA, F,
t, directional tests, and the foolishness of "post hoc" power analysis.

ANOVA2Followup  heterogeneity of variance in the factorial ANOVA in Howell (grad) page 404

Bayesian Stats, Brief Intro

Beyond Significance Testing  my notes from the
text by Rex B. Kline (2004).

Bullshit
Receptivity  nice example of how to present the psychometrics
associated with the development of a new scale

Canonical  why is it called "canonical" correlation?

Certificate in Statistics 
From ECU, Psychology

Comparing Correlated, Overlapping Correlation Coefficients  Steiger's
z.

Comparing Correlated but Nonoverlapping Correlation Coefficients  the PearsonFilon statistic and the ZPF statistic

Comparing k > 2 Independent Correlation Coefficients

Comparing Reliability Coefficients 
procedures for comparing one reliability coefficient to another

Confidence Interval for R^{2}  putting a confidence
interval on R^{2}

Contingency Tables, Low Expected Frequencies 
Is this a problem or not?

Consulting Client Types

Correlation and Causation  When does correlation imply causation?

Correlation and Regression, Assumptions
 fixed versus random X

DataHelp  suggestions on setting up a data file

Dichotomizing Continuous Variables  a bad idea: Discussion from EdstatL.

Effect Size Estimation  An
overview of this topic

Eigenvalues  origin of the term

Excel:

Exploratory Factor Analysis  review of 1999 article by Fabrigar et al.

ehistory  base of the natural log

EX1611  from Howell's fundamentals text, page 333

Factor
Analysis, Number of Factors, code for Parallel Analysis and Velicer's
MAP Test

Greek Alphabet
 many of these letters are used as statistical symbols.

History of
Statistics  useful links to Internet Resources, University of York

HOWL136  exercise 136 from the Fundamentals text

Humor
 jokes involving statistics

Interaction
Significant, Simple Main Effects Not  suggestion on how to deal with
this outcome.

IVDV  Independent and Dependent
Variables

Kolgomorov, A. N.  Obituary for the mathematician whose work had an
enormous influence on statistics and other domains as well.

KR20  KuderRichardson 20

Kurtosis  discussion of kurtosis

Likert  what is a Likert scale and how do you
pronounce "Likert?"

Logit  pronunciations of the word

LESSONS  these are my online lecture
notes for my stats classes

Low Power, Low Reliability  Is it a big problem when results are significant?
 Mediation and Moderation

MetaAnalysis  links to useful resources

Mindless Statistics  Gigerenzer

Monty Hall Dilemma would you switch doors?

Missing Data  suggested readings on the topic of how to deal with missing data

Multiple Regression,
Assumptions  Osborne, J., & Waters, E.
(2002). Four assumptions of multiple regression that researchers should
always test. Practical Assessment, Research & Evaluation, 8(2).

Multivariate Normality  a few
links to get one started on this topic

NHSTSHIT  Jack Cohen's wit and a list of
references on significance testing.

NHSTQuiz A little TrueFalse quiz to test your
understanding of Statistical Hypothesis Inference Testing

Nonparametrics  common misconception that nonparametrics have no assumptions

NormSample Comparison
 comparing your sample mean and variance to
that of a normative group

Normality Assumption  EDSTATL
discussion on checking data for compliance with an assumption of normality

OmegaSquared  advice on interpreting the omegasquared statistic

OneTailed NHST  does it ever make sense to test directional
hypothesis?

OPSCAN  using OPSCAN data sheets in your research

p Values and the American Statistical Association

p Values
and the American Statistical Society

pexact  why researchers should report exact p values

p values suspiciously distributed  something here smells like
rotten p

Pairwise Comparisons  discussion of pairwise/multiple comparisons procedures, including common misconceptions about them

Proportions  Pairwise
comparions for three or more independent proporotions

PathMatrix  using matrix algebra to get effect coefficients in path analysis

Pearson
r, Critical Values

Pitman's T  testing variances with correlated samples

Poems  Poems about statistics

POWER
 An overview

Probability of Replication  is this new statistic
of any value?

Quotes about Statistics
 The average human has one breast and one testicle.

R: Learning Statistics with R

Randomness  what does it really mean when we
say an event is "random?"

Regression Towards the Mean

Reliability  a few notes on reliability from Nunnally's text

Resampling Statistics  a brief introduction to bootstrapping and permutation/randomization tests

Research Wahlberg 
Facebook page for stats/research geeks

ReversalParadox  discussion of the reversal paradox,
also known as Simpson's paradox.

Sample Size Does NOT Affect the Probability
of a Type I Error

Sample Size Required, Finite
Population, Survey with Dichotomous Responses

SAS  help using the SAS stat pack

ScalesTransform  nonlinear data transformations

SignifTesting  why Frank Schmidt thinks significance testing the devil's work

Simpson  Simpson's paradox, with bibliography

Skew  location of mean, median, mode in skewed distributions

Split in Half Splitting a data file into two
random halves

SPSS  Help using the SPSS stats pack

SPSS2Excel2SAS  write SPSS data to Excel and then bring into SAS

SSType  different types of sums of squares

Standardized Confidence Intervals  why not standardize confidence intervals

Statistician as Detective

Stepwise  stepwise procedures are the devil's work

Student's t Statistic 
why "t" ?

tCLT  nonrobustness of the
t statistic

tCrit  t approximated by z and some criticisms of significance testing

Type I Errors  How frequent are Type I errors in the published literature?

TypeIIIErrors  Evaluating the Relative Seriousness of Type I versus Type II Errors in Classical Hypothesis Testing

Type III Errors  Correctly rejecting the null but incorrectly inferring the direction of effect

Is .039 Larger or Smaller than .05?

Why Standardize?  when is it helpful to
standardize effect size estimates rather than presenting them in
unstandardized form?
Return to Dr. Wuensch's Statistical Resources Page.
Contact Information for the Webmaster,
Dr. Karl L. Wuensch
This page most recently revised on 21January2017.