Research Methods Flashcards
Between groups design
Using separate groups of participants for each of the different conditions in the experiment.
Within subjects design
Each participant is exposed to all the conditions of the experiment.
Ratio data
Data is measured in units on a constant scale, with an absolute zero value.
Interval data
Data is measured in units on a constant scale, with equal intervals. No “zero” value.
Nominal data
When data is categorised based on an equivalent feature (i.e. name, gender, number).
Ordinal data
Ordered by rank e.g. 1st, 2nd, 3rd.
N.B. Tells us nothing about differences between values.
Level of measurement
Relationship between what is being measured and numbers obtained on a scale (i.e. accuracy of measurement.
Empirical
Gathering evidence through observation and measurement that can be replicated.
Measurement error
A discrepancy between the number we use to represent the thing we are measuring and the actual value.
What a score consists of:
1) True score
2) A score for other things we are inadvertently measuring
3) Systematic bias
4) Random error
Discrete variable
No underlying continuum. No overlapping categories. Clear beginning and end.
Continuous variable
A continuum with no clear beginning or end.
Does correlation imply causality?
1) Tertium quid - a third measurable factor of intermediate value.
2) Direction of causality - A = B but not vice versa.
Inductive reasoning
Reasoning based on probable premises.
Premise 1: I like dogs
Premise 2: I like cute animals
Conclusion: Dogs are cute.
Mill’s criteria for causality
An improvement on Hume’s:
1) Cause must precede effect.
2) Cause and effect should correlate.
3) All other explanations of cause-effect relationship rules out.
Hypothesis bias
People have a natural bias to confirm hypotheses rather than reject them.
Control condition
Condition in which cause is absent. Acts as a baseline for comparison.
Independent variable
The variable that is manipulated.
Dependent variable
The variable that is measured as a result (a.k.a. Outcome variable).
How to remove tertium quid
1) Control other factors.
2) Randomisation.
Importance of randomisation
Avoid systemic bias - to ensure an equivalent spread of attributes across groups.
How to increase confidence
1) Significance (e.g. p<0.05).
2) Randomisation.
3) Replication.
Correlational study
Naturally occurring phenomenon without interference.
Weakness = not causal.
Experimental study
Environment is manipulated in some way.
Weakness = not natural.
Why do we prefer parametric tests?
1) There is a greater variety of parametric tests so can analyse a greater variety of situations.
2) Generally better at finding experimental effects.
Self-report considerations
1) Content validity
2) Criterion validity
3) Factorial validity