Causality

Question 1

What is the purpose of an experiment?

Answer 1

To demonstrate causality.

Question 2

What are the three requirements for causality?

Answer 2

• Temporal precedence: cause must precede effect in time.
• Correlation/covariation/empirical relationship: Cause and effect must be empirically correlated with one another.
• No alternate explanations/no confounds: The relationship between the cause and effect cannot be explained in terms of a third variable.

Question 3

What are the three features of an experiment?

Answer 3

1. Establishing independent variables: Creating experimental conditions or comparisons that are under direct control of the researcher.
2. Controlling extraneous variables: these are not of interest to the researcher and they must be controlled, otherwise they lead to confounding.
3. Measuring dependent variables: behaviours that are measured in the study. These must be defined precisely.

Question 4

What are independent variables? (TIMS)

Answer 4

• They must have a minimum of two levels.
• They may be manipulated variables (controlled by the experimenter) or subject variables (inherent in the participant).
• They may be situational: features of the environment that participants may encounter (e.g. noise or silence).
• They may be a task: variations in the task given to participants
• They may be instructional: variations in the instructions given.

Question 5

What do we know about controlling extraneous factors?

Answer 5

• We need to control anything that’s not of interest to us.
• We need to eliminate any third variable explanations.

Question 6

What does the credibility of an experiment rely on?

Answer 6

• The credibility of an experiment depends on (amongst other things) the operational definition of the measured outcomes.

Question 7

What is the experimenter effect?

Answer 7

When the researcher gives subtle clues about the way in which they expect subjects of a study to respond.

Question 8

What are demand characteristics?

Answer 8

Certain features of the research setting that can impact the findings. (they make the subject act in ways they think the researcher would like them to)

Question 9

What is an operational definition?

Answer 9

How the construct is defined in terms of specific operations, measurement instruments, or procedures through which it can be observed.