Quantitative Lecture 3 Flashcards
What is a variable?
A variable is anything that varies, such as height, weight, age, IQ, and introversion.
How are variables measured in quantitative psychology?
Variables are measured numerically.
What is an independent variable (IV)?
The variable that the experimenter manipulates to make predictions about the dependent variable (DV).
What are the types of independent variables?
Types of IVs include experimenter (manipulated) variables and participant (subject) variables.
What is a dependent variable (DV)?
The variable that is measured or recorded in an experiment, representing the subjects’ response.
What is a control variable?
A variable that is held constant or corrected for to avoid affecting the DV.
What are extraneous variables?
Variables that potentially influence results but are not of direct interest to the research.
What is a continuous variable?
A variable that can take any value within a given range, such as temperature or levels of anxiety.
What is a discrete variable?
A variable that can take on only certain discrete values, like the number of cars owned.
What is a categorical variable?
A variable whose value is a category, such as gender or occupation.
What is dichotomising variables?
The process of converting continuous or discrete variables into two categorical variables for comparison.
What are potential drawbacks of dichotomising variables?
Loss of information and difficulty in deciding what constitutes high and low.
What role does experimental design play in psychological research?
It allows investigation of causal relationships through manipulation of the IV.
What is causation?
Causation is when one thing causes another.
What is within-subjects design?
A design using the same participants in every condition of the IV.
What are the advantages of within-subjects design?
Equivalent groups and the need to recruit fewer participants.
What are the disadvantages of within-subjects design?
Order effects, practice effects, carryover effects, and attrition.
What is between-subjects design?
A design using different participants in each condition of the IV.
What are the advantages of between-subjects design?
No order effects and fewer demand effects.
What are the disadvantages of between-subjects design?
Need to recruit more participants and inability to control for individual factors.
What is random allocation?
A method ensuring equal opportunity for participants to be assigned to each group.
What is mixed design?
A research design that includes a combination of between-subjects and within-subjects factors.
What is counterbalancing?
A method used to eliminate order effects by varying the order of conditions.
What are asymmetrical order effects?
Order effects that have greater strength in one specific order of conditions.
What is a representative sample?
A sample that contains sub-groups of people in proportion to their prevalence in the population.
What is the difference between population and sample?
Population is the wider group of interest, while sample is the group selected for research.
What does WEIRD stand for?
Western, Educated, Industrialized, Rich, Democratic.
What is sampling or selection bias?
When certain categories are over- or under-estimated in a sample.
What are the two main types of sampling strategy in psychology?
Probability-based sampling and non-probability sampling.
