Correlational studies Flashcards
What’s correlation?
A correlation is a relationship between two variables
What’s a correlational study?
test between variables
and to see if related and if so how strong and if their co variables
When do we use a correlational design?
To test realtionship between 2 variables
e.g. age and reaction time
How to use correlation?
1-decide what co variables were measuring and operationalise them
2- measure p’s on bith covariants
3-plot variables on scatter graphs to see relationship
4-carry out test to see if relationships significant or chance producing a correlation coefficient
What’s a positive correlation? and example
When one variable increases another increases
The taller a person is the heavier they are
what’s the coefficient of a positive correlation?
0- +1
Diagram of positive correlation?
*
| *
| *
| *
| *
|_ *_ _ _ _ _ _ _ _
What’s a negative correlation and example?
As one variable increases the other decreases
The more alcohol you drink the less you can remember
What’s the coefficient of a negative correlation?
0 to -1
Graph of a negative correlation
*
| *
| *
| *
| *
|*_ _ _ _ _ _ _
What is no correlation and example?
Theirs no relationship between variables
Shoe size and iq
what’s no correlation coefficient
close to 0
No correlation graph?
|. * *
|*. *
|. . *
|. *
|. *
|_ *_ _ _ _ _ _ _ *_ _
The higher the number?
The stronger the coefficient
What’s a correlation hypothesis?
The hypothesis will state realtionship between 2 co variables
Non directional- there will be a correlation
Directional- their will be a pos/neg correlation
Null- their will be no significant correlation
Does correlation = causation
no, just because theirs a correlations doesn’t mean theirs a cause
1 X caused Y
2 Y caused X
3 Z causes a change in both X and Y
Positives of correlation research?
-high ecological
-precise info
-makes use of existing data
-quiche and easy
Negatives of correlation research?
-impractical and unethical
-lacked internal and external validity
-no cause and effect relationship can be inferred
Graph of a curvilinear graph
P|. .
E|. /. \
R|. /. \
F|. /. \
o|. /. \
R|. /. \
M|. /. \
A|. /. \
n|. /. \
C|. /. \
E|/_______________________________
Low. medium. high
Arousal
