Embed the explorers
The lab's test explorers can sit on your own page: a course site, a blog post, a learning platform. Your readers move the sliders and see the p-value and the picture change, without leaving your page. It is free and needs no account.
How to embed an explorer
Or copy one of the snippets below, which open each explorer with its standard set-up.
Language, theme and size
In the address, lang=en, nl, pl or de sets the language (English if left out) and theme=light or dark the colours (light if left out). The frame takes the width you give it, down to a phone's 320 pixels; at a height of 720 pixels the data, the chart and the answer fit on a laptop without scrolling.
Privacy and the link back
An embed sets no cookies and stores nothing on your readers' devices. The lab counts anonymous page views on its server, including the name of the site an embed is shown on; IP addresses are not stored. Each embed has a small link to the full explorer in the lab, which opens in a new tab.
The explorers
The one-sample t test
Is a mean different from a promised value? The t statistic on its curve, with the p-value shaded as you move the data.
Open the explorerTwo means: Welch, pooled and paired t tests
Did the new portal get people paying sooner? Compare two means with Welch's t test, the pooled test or the paired test, and watch the interval for the gap.
Open the explorerProportions: one and two, z and exact
Is 94 % on time below the 95 % promised? Did the new portal convert more customers? Test one or two proportions with the z test or an exact test.
Open the explorerChi-square tests: goodness of fit and independence
Does the contact mix match the forecast? Does payment method depend on segment? Type the counts and see each cell's share of χ².
Open the explorerVariances: χ², F, Levene and Fligner–Killeen
Is this filling line more erratic than the spec allows? Is one book riskier than another? Test a spread against a spec, or two and more spreads against each other.
Open the explorerOne-way ANOVA with Tukey's test
Does days-to-payment differ by region, and which regions? One-way ANOVA from each group's summary, then Tukey's intervals for every pair.
Open the explorerRank tests: Mann–Whitney, Wilcoxon and Kruskal–Wallis
My data are skewed and n is small. Now what? Compare groups by their ranks, with the exact distribution when the samples are small.
Open the explorerCorrelation tests: Pearson and Spearman
Do two numbers move together, or is the pattern luck? Test Pearson's r or Spearman's ρ and see the interval for the correlation.
Open the explorerRates over exposure: the Poisson rate ratio
Claims per vehicle-year, incidents per machine-hour: compare two rates when the groups had different exposure, with the score, Wald or exact test.
Open the explorerPaired proportions: McNemar's test
Two models scored on the same cases: is the challenger really more often right? McNemar's test looks only at the cases where they disagree.
Open the explorerEquivalence testing (TOST)
"Not significant" cannot say "no material change". An equivalence test can: two one-sided tests against a margin you set in advance.
Open the explorer