correlations Flashcards
what does a correlation illustrate
strength and direction of an association between 2 or more co-variables
what are co-variables
- variables investigated within a correlation (eg. height/weight)
- not referred to as IV or DVs as correlation investigates association between variables rather than the cause-effect relationship
where are they plotted
scattergrams - once co-variable on x-axis and one on y-axis
what are the three types of correlation
- positive correlation
- negative correlation
- zero correlation
define a positive correlation
as one co-variable increases, so does the other
define a negative correlation
as one co-variable increases, the other decreases
define zero correlation
no relationship between co-variables
difference between correlations and experiments
- experiment = researcher controls/manipulates IV and measures effect on DV
- correlation = no manipulation of one variable and thus, not possible to establish cause/effect between 1 co-variable & another
strengths of correlations - useful preliminary tool for research (1)
P: useful preliminary tool for researcy
E: by assessing strength/direction of a relationship, they provide precise & quantifiable measure of how 2 variables are related - may suggest ideas for future research if variables strongly related/interesting pattern
—-> often used as starting point to assess possible ptterns between variables prior to researchers committing to a study
strengths of correlations - quick & economical (2)
P: relatively quick & economical to carry out
E: no need for controlled environment & no manipulation of variables - secondary data can be used which means they’re less time-consuming
limitations of correlations - tell us how variables are related not why (1)
P: tell us why variables are related and now why
E: cannot demonstrate cause/effect and thus, we do not know which co-variable is causing the other to change —> establishing direction of effect is an issue
limitations of correlations - untested variables (2)
P: possible that untested variables are causing the relationship = intervening variable
eg. high pressuring jobs can cause anxiety and these people also drink a lot of caffeine as they work long hours - intervening variable is job type
limitations of correlations - misused/misinterpreted (3)
P: correlations occasionally misused/misinterpreted
E: relationships between variables sometimes presented as casual when they’re not - esp. by media