Correlations Flashcards
what are the common uses of correlational method?
- measuring reliability and validity in a study
- assesses concordance rated of twin studies
- relationship between change thats already occurred
- relationship between 2 variables that would be unethical to manipulate
what does correlational research refer to?
both vr=ariables are measures to there is no manipulated variable
what are the different types of correlation?
- positive
- negative
- curvilinear
- no correlation
what is a positive correlation?
2 variables increase/decrease together
I /
I /
I/____
what is a negative correlation?
as 1 variable increases the other decreases
I \
I \
I____
what is a curvilinear correlation?
correlation may begin as positive relationship and then change to become negative or vice versa
(U/inverted U shape)
what will be shown on a graph if there is no correlation?
random scatter of results
how do you display correlational data?
scattergram/scatterplot
what is a scattergram/scatterplot?
- used to display data, indicated if there is a correlation
- makes outliers identifiable
- more linear shape plotted the stronger the correlation
what is the correlation coefficient (r)?
- measures strength and direction of data
- strength of correlation is indicated by value of r which ranges from 0-1
- 0 = no relationship, 1 = very strong relationship
- larger correlation coefficient, more statistically significant
what is the direction of the correlation coefficient indicated by?
whether value of r is positive or negative (correlation)
what is the statistical significance of the correlation coefficient determined by?
size of correlation coefficient and size of sample in the study
