Research library.
Choose a concept. Read the definition, explore an example and test your understanding.
48 concepts
Behaviour and bias2 min read
Selection bias
Who enters a study can systematically distort its result.
Beginner
Behaviour and bias2 min read
Recall bias
Systematic differences in remembering past experiences.
Beginner
Data literacy2 min read
Missing data
Distinguish absent values from meaningful answers.
Beginner
Sampling2 min read
Weighting
Adjust how much each observation contributes to an estimate.
Intermediate
Statistics3 min read
Effect size
Express how large a difference or relationship is.
Intermediate
Statistics3 min read
Statistical power
The probability of detecting a specified real effect.
Advanced
Research design3 min read
Confounder
A common cause that can distort an association.
Advanced
Statistics3 min read
Multiple testing
Consider false alarms across a set of tests.
Advanced
Statistics3 min read
Bonferroni correction
A simple way to limit false positives across a test family.
Advanced
Statistics3 min read
Type II error
Fail to reject a null hypothesis that is false.
Intermediate
Statistics3 min read
Practical significance
Evaluate whether a finding matters for a real decision.
Intermediate
Statistics3 min read
Standard error
How much an estimate varies across samples.
Intermediate