Correlations Flashcards
1
Q
what does a correlation illustrate?
A
the strength and direction of an association between two or more co-variables
2
Q
what are correlations plotted on?
A
scatter diagrams
3
Q
is there and IV or cause and effect in correlational investigations?
A
no
4
Q
what is the correlation coefficient?
A
the numerical indicator of strength and direction of a linear relationship between two co-variables
5
Q
4 strengths of correlations
A
- can detect pattens in data and see how 2 variables relate to each other so predictions can be made about the likely values of variables
- can eliminate cause and effect between variables if no correlation is found between them
- large amounts of data can be gathered more quickly and efficiently than experimental designs
- useful when manipulation is pactically or ethically impossible
6
Q
3 disadvantages of correlations
A
- cannot est. C/E so cannot say which variable changed the other or if a third variable is involved
- curvilinear relationships cannot be picked up by correlational analysis so must take care to see that graph shows appropriate linear pattern
- variables must be quantified to be measured, which cna affect construct validity
7
Q
what type of correlation is +0.5?
A
moderate to strong positive
8
Q
what type of correlation is -0.3?
A
weak negative
9
Q
what type of correlation is +0.97?
A
strong positive
10
Q
what is the range of correlation coefficients?
A
-1 to 1
