Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can draw the four-outcome table and say which cells are correct decisions and which are errors. (Guide: “Why a test can be wrong”; Practice Q1)
- I can define power as the probability of correctly rejecting a false H₀, for a stated true value. (Guide: “The probability of each error”)
- I can explain why, after a decision, only one type of error is possible. (Guide: “Type I and Type II errors”; Practice Q6)
- I can explain why α and the sample size should be chosen before collecting data. (Guide: “Consequences decide the design”; Practice Q7)
Calculation
- I can state that P(Type I error) = α. (Practice Q5)
- I can find P(Type II error) as 1 − power. (Guide: Worked example 2; Practice Q2, Q5)
- I can use a table of power values to compare study designs. (Guide: Worked example 2)
Reasoning
- I can describe a Type I error and a Type II error in context, giving both the conclusion and the truth. (Guide: Worked example 1; Practice Q4)
- I can interpret a power value in context. (Practice Q5, Q7)
- I can predict how changing n, the standard error, the true value or α affects the power and the Type II error probability. (Guide: “What affects the power”; Practice Q3, Q5)
- I can describe a consequence of each error and decide which is more serious. (Guide: Worked example 1; Practice Q4, Q7)
- I can use the more serious error to justify a choice of α or of sample size. (Practice Q4(c), Q7(b))
All ticked? Move on to Topic 3.9, Sampling Distributions for the Difference Between Sample Proportions, or return to the course roadmap.