Type I & Type II ErrorsThe two ways a test can be wrong, and the trade-off between them.MathematicsType I errorRejecting a null hypothesis that istrueA false positiveIts probability is α, the level yousetControlled directly by yourchoice of αLowering α makes it rarerThe error a sceptic worries aboutType II errorFailing to reject a false nullhypothesisA false negativeIts probability is βPower is 1 − βMore data or a larger effectraises powerThe error an optimist worriesaboutTHE DIFFERENCE THAT MATTERSFor a fixed sample size, lowering α raises β. Only more dataimproves both at once.Power depends on effect size, α, variability and n. Once a study isdesigned, n is the only one still under your control. EducationalType I & Type II Errorslearnposters.com
Type I & Type II Errors — printable math wall chart from LearnPosters. Free vector PDF, US Letter and A4.

What’s on the Type I & Type II Errors poster

Type I error against Type II error, side by side.

Power depends on effect size, α, variability and n. Once a study is designed, n is the only one still under your control. Educational reference.

Questions about the Type I & Type II Errors poster

What’s on the Type I & Type II Errors poster?
Type I error against Type II error, side by side. Type I error: Rejecting a null hypothesis that is true; Type I error: A false positive; Type I error: Its probability is α, the level you set; Type I error: Controlled directly by your choice of α; Type I error: Lowering α makes it rarer; Type I error: The error a sceptic worries about; Type II error: Failing to reject a false null hypothesis; Type II error: A false negative; Type II error: Its probability is β; Type II error: Power is 1 − β; Type II error: More data or a larger effect raises power; Type II error: The error an optimist worries about; For a fixed sample size, lowering α raises β. Only more data improves both at once.. Power depends on effect size, α, variability and n. Once a study is designed, n is the only one still under your control. Educational reference.
Who is the Type I & Type II Errors poster for?
Type I & Type II Errors belongs to the Mathematics section rather than to a school year, because math is not something one grade owns. Anyone learning probability & statistics can pin it up — a beginner, a student mid-course, or someone revising years later.
When should you use the Type I & Type II Errors poster?
When choosing a significance level, or explaining why a study found nothing. A wall chart earns its place by being glanceable from where the work is happening, so Type I & Type II Errors belongs on the wall where that math work actually happens, within glancing distance, rather than filed away.
What other posters go with Type I & Type II Errors?
Bayes' Theorem, Central Limit Theorem and Conditional Probability sit alongside Type I & Type II Errors in the Mathematics section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.Bayes' TheoremCentral Limit TheoremConditional Probability
Is the Type I & Type II Errors poster free to download and print?
Yes. Type I & Type II Errors downloads as a free PDF with no account, no email and no watermark, like everything else in the Mathematics section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
What size does the Type I & Type II Errors poster print at?
Type I & Type II Errors is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of Type I & Type II Errors loses nothing.Printing guide

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