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

Psychologist trying to figure out a fourway
ANOVA interaction

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}

Consulting (Statistical) Provided by Graduate
Students
 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.
 Dichotomous Variable,
Mean and Variance
 Distribution
Zoo  visualize various distributions, interactive
 Do My Online Statistics Class For Me
 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?

Matrix Calculator
 Mediation and Moderation
 MetaAnalysis  links to useful resources
 Mindless Statistics  Gigerenzer
 Monty Hall Dilemma would you switch doors?
 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
 Odds
Ratios versus Probability Ratios
 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  The reign of p values is
over

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
 pvalues
 Response by the American Statistical Society on pvalues
 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
 Power Primer
by Daniël Lakens  thorough overview for correlated and independent t
tests and ANOVA.
 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
 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
 Significant or Not?
 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" ?
 Subjects  What are Subjects?
 tCLT  nonrobustness of the t statistic
 tCrit  t approximated by z and some criticisms of significance testing
 Transformations to Reduce Skewness
 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?
 Univariate Regression
 Variance Inflation Factor  Rules of Thumb
 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 29June2021.