Research Methods : Correlations Flashcards
What is a correlation
A mathematical technique in which a researcher investigates and association/relationship between two variables, called co-variables.
What are co-variables
The variables investigated within a correlation, for example height and weight.
Why not independent and dependent variables
Correlation investigate association not cause and effect
What is a positive correlation
As one co-variable increases so does the other
What is a negative correlation
As one covariable increases the other decreases.
What is a zero correlation
When there is no association/relationship between the co-variable
What are correlations plotted on
A scatter gram
Each co-variable on axis
What is the strength of an association/relationship measured using
Correlation coefficient
What does correlation coefficients range from
-1.0 to +1.0
What does a + and - coefficient mean
+ = positive correlation and - means negative correlation
he closer the coefficient is to -1 or +1 what does it mean
The more strongly the two variables are related
List the strength of the correlation for the following
0.8-1, 0.5-0.8 , 0.3 to 0.5 , 0-0.3
0.8 – 1 = strong correlation • 0.5 – 0.8 = mild correlation • 0.3 – 0.5 = weak correlation • 0 -0.3 = no correlation Closer to 0 , more zero correlation
What are the differences between experiment and correlation
No manipulator of IV to see effect on DV
So no cause and effect in correlation
Even if strong correlation between co variables
Cannot assume cause
Presence of intervening variables that could influence the relationship between co variables
Give an example of intervening variables
strong positive relationship between caffeine and anxiety level
Other intervening variable such as personality , personal problems stress for this relationship
Cannot say caffeine increases anxiety levels
What is strength of correlations
Correlations are relatively quick and cost-effective to carry out.
There is no need for a controlled environment and no manipulation of variables is required.
Secondary data (data collected by others) can be used, which means correlations are less time consuming and less expensive than experiments.
Correlations are useful as a preliminary tool for research. For example, assessing the strength and direction of a relationships can provide a precise and quantifiable measure of how two variables are related. This could suggest ideas for future research. Therefore, correlations are often used as a starting point to assess possible patterns between variables
What are the limitations of correlations
lack of experimental manipulation and control within a correlation, studies can only tell us that variables are related not why
temperature increases so does the number of ice- creams sold. However, they cannot tell is why they are related.
suffer from the third variable problem where another untested variable is causing the relationship between the co-variables.
Caffeine-anxiety example
Another variable could be causing the relationships between two co-variables but we might be unaware of what it is
Correlations can occasionally be misused or misinterpreted.
The media often present the relationships between variables as “causal” facts (i.e. there is a cause effect relationship
Not same in reality
