Quantitative/ Analysis
t-tests
Compare means with the right dependence model
A t-test estimates and tests a mean against a reference or another mean. Independent-group Welch tests allow unequal variances; pooled Student tests assume equal variances. Paired tests analyse within-pair differences, while one-sample tests use one set of observations. The unit of independence and chosen estimand determine the appropriate version.
WHEN IT FITS
Use for a prespecified comparison involving a continuous outcome and one mean or two conditions. Establish whether observations are independent or paired before selecting the test and uncertainty estimate.
Strengths
- Direct estimate of an interpretable mean difference
- Welch handles unequal group variances without preliminary switching
Limitations
- Outliers and severe skewness can impair small-sample inference
- Repeated unplanned tests inflate false-positive risk
Know the boundary
A nonsignificant t-test does not demonstrate equivalence; use an equivalence design with justified bounds for that claim.
USED ACROSS
Banking & financeBusiness & MBAPsychologyComputer scienceEducation