Confidence Intervals

Info sheet · Statistics for Psychology & Neuroscience

Author

Andrew Bell

Published

August 13, 2026

Info sheet 0.1 (skeleton) · Prerequisites: the normal distribution; standard error · Give feedback ↗

Working notes for the author — not shown to students once collapsed; remove before publishing.

What you’ll get from this sheet

By the end you should be able to:

  1. Interpret a confidence interval correctly.
  2. Relate the 95% CI to the standard error and the 68–95–99.7 rule.

A 95% confidence interval is estimate ± ~2 standard errors. Correct reading: over many repeated samples, 95% of such intervals contain the true value — not ‘95% chance the truth is in this one’.

[Main idea]

TODO — write the core explanation in transcript voice.

[Interactive demo]

TODO — native <input> + string-built SVG / OJS widget (see any built sheet for the pattern).

See it in code

# TODO
# TODO

TODO — a short question.

TODO — the worked answer.

TODO — a common mistake and how to avoid it.

Where this shows up next

TODO — link to the relevant book chapter.