Variables and Measures 2 Flashcards
What is Steven’s theory of measurement?
Ratio data, Nominal Data, Ordinal data and Interval data
What is a mediator variable?
Variable responsible for the relationship between variable A and variable B. e.g. pub quiz on general knowledge. The ID is age, the DV pub quiz scores. The mediator variable in this is educational experiences.
What is a moderator variable?
ID and DV relationship is inconsistent throughout the data. e.g. pub quiz scores may vary between men and women so different conclusions are needed
What is an advantage of operationalisation?
Makes the nature of the concept explicit
Researchers can’t confuse what you’re measuring or interpret the variable differently
What is a disadvantage of operationalisation?
Researchers now focus on measurement issues rather than the conceptual ones. e.g. measuring love, can be defined as spending lots of time together but in reality it has little to do with what love is.
What are the 3 main conditions for establishing causality?
Covariance: Measure whether the DV changes when the IV changes, change in X means a corresponding change in Y, in observations
Temporal precedence: in study designs (under researcher control), X changes before Y, we manipulate IV, measure DV
Exclusion principle: if there is a change in Y then X is the only possible cause, in study designs (under researcher control), our IV is separate from all other variables
What are extraneous variables?
Affect the dependent variable if uncontrolled
They need to be eliminated
e.g. condition a runs at 9am after breakfast, condition b runs in the evening after dinner. Performance in condition B is worse as people haven’t eaten in condition B unlike in the morning
What are confounding variables?
Affects both DV and IV
Needs to be eliminated
e.g. condition A has a complicated stimuli, condition B has a simple stimuli, condition A is worse than B, stimuli has changed affecting DV and IV
