6. correlations

Question 1

what does a correlational study look at

Answer 1

the relationship between two things/ variables
in correlation called co-variables

Question 2

what is a correlation coefficient

Answer 2

calculation of a statistic using correlation techniques, a statistic value between +1 and -1

Question 3

how are correlations plotted

Answer 3

onto a scattergram to visually see if the correlation is positive, negative or zero correlation

Question 4

what is a positive correlation

Answer 4

as one variable increases so does the other
+0.2 is a weak positive correlation
+0.9 is a strong positive correlation

Question 5

what is a negative correlation

Answer 5

as one variable increases the other decreases
anything measured below 0 on the correlation coefficient becomes a negative correlation
-0.2 is a weak negative correlation
-0.9 is a strong negative correlation

Question 6

what is a zero correlation

Answer 6

shows no relationship between two variables
anything measured close to 0 on the correlation coefficient shows zero correlation
-0.02 shows no correlation
+0.06 shows no correlation

Question 7

what takes place in an experiment

Answer 7

experimenter deliberately manipulates IV
the impact of each condition/ level of IV is measured
experimenter establishes cause and effect

Question 8

what takes place in a correlation

Answer 8

no deliberate change made to any variable
the impact of one variable on another isn’t measured, just the relationship between co-variables
experimenter cannot establish cause and effect as there may be a third unmeasurable variable that influences the relationship

Question 9

strengths of a correlational analysis

Answer 9

indicate the direction of the relationship between two variables
provides quantitative measure
researcher knows whether to carry out an experiment into the topic

allow researchers to statistically analyze situations that can’t be manipulated for ethical reasons
eg wouldn’t be ethical to set up situations where children display aggressive behavior to measure the impact of different environments on aggression
researcher can unravel complex relationships

Question 10

limitations of a correlation analysis

Answer 10

do not establish cause and effect only establish a relationship
eg a positive correlation between hours spent in a day care and aggressive behavior doesn’t mean the day care causes aggression
have to be careful drawing conclusions from correlations

non-linear relationships can’t be measured by correlation techniques
a correlation that once was positive can become a negative correlation meaning no meaningful relationship is indicated by the correlation coefficient
a relationship may be missed