Unit 6

Topics:

Note: All topics below are summarized by the following note outline: Research Design

**Measurement **

- Learning Objectives

- Define reliability
- Describe reliability in terms of true scores and error
- Compute reliability from the true score and error variance
- Define the standard error of measurement and state why it is valuable
- State the effect of test length on reliability
- Distinguish between reliability and validity
- Define three types of validity
- State the how reliability determines the upper limit to validity

**Basics of Data Collection**

- Learning Objectives

- Describe how a variable such as height should be recorded
- Choose a good response scale for a questionnaire

**Sampling Bias**

- Learning Objectives

- Recognize sampling bias
- Distinguish among self-selection bias, undercoverage bias, and survivorship bias

**Experimental Designs**

- Learning Objectives

- Distinguish between between-subject and within-subject designs
- State the advantages of within-subject designs
- Define “multi-factor design” and “factorial design”
- Identify the levels of a variable in an experimental design
- Describe when counterbalancing is used

**Causation**

- Learning Objectives

- Explain how experimentation allows causal inferences
- Explain the role of unmeasured variables
- Explain the “third-variable” problem
- Explain how causation can be inferred in non-experimental designs

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