The survey and research analyst
toolbox.
Test differences, size experiments, summarise NPS and correct for many comparisons.
Keep this toolbox for offline use
17 useful places to start.
Tests assume independent observations and a plan made before looking at the data. Statistical significance is not the same as practical importance.
P-value and critical value calculator
Convert a z, t, chi-square or F statistic into an exact p-value and critical value.
One-way ANOVA calculator
Compare the means of two or more groups with an F test and an ANOVA table.
A/B test significance calculator
Test whether the difference between two conversion rates is statistically significant.
A/B test sample size calculator
Estimate how many visitors each variant needs to detect a chosen change in conversion rate.
2×2 table: risk ratio, odds ratio and Fisher exact test
Analyse a 2×2 table of exposure and outcome counts with risk ratio, odds ratio and exact p-values.
Multiple comparisons p-value correction
Adjust several p-values with Bonferroni, Holm or Benjamini–Hochberg corrections.
Net Promoter Score calculator
Calculate NPS and its margin of error from response counts or raw 0–10 scores.
Survey sample size estimate
Plan a sample for a proportion using a supplied margin of error.
Wilson proportion interval
Calculate a bounded confidence interval for a count out of a sample.
Confidence interval for a mean
Estimate a mean interval using a sample and Student’s t distribution.
Welch two-sample t test
Compare independent sample means without assuming equal variances.
Contingency table chi-square test
Compare two categorical variables using an observed count table.
Independent-samples effect size
Compare two sample means in pooled standard-deviation units.
Descriptive statistics
Mean, median, mode, spread and standard deviation for your numbers.
Pearson correlation test
Test and measure the straight-line relationship between two variables, with a confidence interval and regression line.
Cohen’s kappa calculator
Measure agreement between two raters beyond chance, with optional weights for ordered categories.
Mann–Whitney U test calculator
Compare two independent groups without assuming a normal distribution, with exact p-values for small samples.
A few things you
can tick off.
- Check whether an A/B test is significant
- Work out the visitors a test needs
- Adjust p-values for many comparisons