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 define bias as a systematic error in the method that makes a statistic consistently too high or too low. (Guide: “Bias: a fault in the method, not bad luck”)
- I can tell bias apart from chance variation between random samples, using a set of repeated results. (Guide: Figure 1; Practice Q7)
- I can explain why convenience samples and voluntary response samples are likely to be biased. (Guide: “Nonrandom samples”; Practice Q1, Q3)
- I can explain why a larger sample does not remove bias. (Guide: Worked example 2; Practice Q3, Q6, Q7)
Skills
- I can identify voluntary response bias in a described study. (Practice Q1, Q6)
- I can identify undercoverage bias, including undercoverage caused by an incomplete list. (Guide: “Undercoverage bias”; Practice Q2)
- I can identify nonresponse bias and calculate a response rate. (Guide: Worked example 2; Practice Q5)
- I can identify response bias from leading or confusing wording, self-reported answers or faulty measurement. (Guide: “Response bias”; Practice Q4, Q7)
- I can tell nonresponse apart from voluntary response by asking who decided who is in the sample. (Guide: “Nonresponse bias”)
Reasoning
- I can state whether a biased method is likely to overestimate or underestimate the parameter, with a reason in context. (Guide: “Writing about bias”; Practice Q2, Q5, Q6)
- I can find more than one source of bias in the same study and give the direction of each. (Guide: Worked examples 1 and 2; Practice Q5)
- I can compare two sampling plans and justify which is less likely to be biased. (Practice Q3, Q6)
All ticked? Move on to Topic 1.13, Experimental Design, or return to the course roadmap.