Tester

Choose a test and enter data

Default decision rule: p < alpha indicates statistical significance

Test type
T-test entry mode

Detail

Supporting summary

Use the preset library to quickly test common manufacturing comparisons like before/after cycle time, line-to-line output, or defect distributions.

Preset Guidance

When to use each test

T-test: Compare two means, such as before vs. after improvement or Process A vs. Process B.

ANOVA: Compare three or more groups, such as shifts, lines, or suppliers.

Chi-square: Compare categorical count patterns, such as pass/fail by shift or defect type by supplier.

Instructions

How to use this app

  1. Pick the manufacturing preset that most closely matches your question.
  2. Confirm the test type or switch to another test if the preset is not a perfect match.
  3. Enter raw sample data, or for t-tests, switch to summary mode and enter `n`, mean, and standard deviation.
  4. Set the confidence level, then click `Run test`.
  5. Review the p-value, confidence interval, effect size, and plain-English interpretation together before deciding on action.

Statistical significance answers whether the observed difference is unlikely to be due to random variation alone. Practical significance answers whether the difference is large enough to matter operationally.

This app is meant for fast decision support. For regulated or high-risk decisions, confirm the study design, data assumptions, and follow-up analysis before finalizing conclusions.