Chi-Squared Test in Psychology: Formula, Example, Table
For the first twenty-two years of its life, the chi-squared test used the wrong degrees of freedom. Karl Pearson gave a 2x2 table 3 instead of 1, unti…
Category: Articles
Levels of Measurement: Nominal, Ordinal and Interval
Levels of measurement decide which statistical test you are allowed to run, and AQA devotes 25 to 30 per cent of the entire Psychology assessment to r…
Which Statistical Test to Use in Psychology: A Decision Guide
In a review of 513 neuroscience papers, of the studies where a particular comparison mattered, 79 used the wrong statistical procedure and only 78 use…
The Sign Test: Formula, Worked Example and Critical Values
In 1710, a royal physician counted London christening records for 82 straight years, found boys outnumbered girls every single year, and published wha…
Standard Error Explained: Formula, Meaning and SD vs SE
Standard error is mistakenly reported instead of standard deviation in up to 64% of published articles. Understanding the standard error formula, and exactly how it…
T-Tests in Psychology: A Complete Guide
Roughly one in four p-values published across major psychology journals comes from a t-test — making it the single most-used statistical test for comparing two…
What Is a Correlation Coefficient? Pearson’s r and Psychology Statistics
A correlation coefficient of just 0.3 counts as a strong finding in personality psychology, yet most people misread what Pearson’s r actually proves about cause…
Standard Deviation in Psychology: Definition & Calculation
Two psychology classes can score identical averages yet tell completely different stories — standard deviation is the single statistic that reveals whether those scores clustered…
MBTI Stereotypes vs Reality: What Your Type Is Really Like
Discover the truth behind MBTI stereotypes. Learn why popular personality type misconceptions persist and what each of the 16 types is actually like b…
Free MBTI Function Stack Test: Discover Your True Cognitive Profile
Take our free MBTI function stack assessment to discover your cognitive hierarchy. 10-minute test reveals dominant, auxiliary, tertiary & inferior fun…