3.2.1 correlations

Question 1

what is a correlation?

Answer 1

a method used to assess the degree to which two co-variables are related

Question 2

what does a correlation hypothesis predict?

Answer 2

whether or not there is a RELATIONSHIP between two variables

Question 3

what is a positive correlation?

Answer 3

occurs when both co-variables increase at the same time

Question 4

what is a negative correlation?

Answer 4

occurs when as one co-variable increases, the other decreases

Question 5

what is no correlation?

Answer 5

occurs when there is no relationship between the co variables

Question 6

what indicates the strength of a correlation?

Answer 6

correlation coefficient

Question 7

what does a correlation coefficient of 0 indicate?

Answer 7

there is no relationship between the variables

Question 8

what correlation coefficient constitutes a perfect positive correlation?

Answer 8

+1

0.0 to 0.3 as weak, 0.3 to 0.7 as moderate, and above 0.7 as strong

Question 9

what correlation coefficient constitutes a perfect negative correlation?

Answer 9

-1

0.0 to -0.3 as weak, -0.3 to -0.7 as moderate, and above -0.7 as strong

Question 10

what methods obtain correlational data?

Answer 10

• questionnaires
• observations
• experiments

Question 11

how do you analyse correlations?

Answer 11

• spearmans rank
• scatter grams
• calculating correlation coefficient

Question 12

how do you calculate spearmans rank?

Answer 12

• Rank the scores separately
• Complete the d column by calculating the difference between the ranks for each participant (Rank 1 - Rank 2)
• Complete the d2 column by squaring the d column
• Total the d2 column to calculate Σd2
• Complete the formula to calculate the correlation co-efficient.
• Compare the observed value with the critical value.

Question 13

what is a curvilinnear relationship?

Answer 13

both variables increase together but only until a certain point, then as one variable continues to increase, the other decreases

Question 14

what are the strengths of using correlations?

Answer 14

• they may indicate a relationship between 2 variables where experimental proof is impossible and is a good starting point for future experimental research.
• uses quantitative data therefore a relationship can be objectively and clearly analysed on a scattergraph and using Spearman’s Rank to test significance

Question 15

what are the weaknesses of using correlations?

Answer 15

• they do not prove cause and effect conclusions, just a relationship, therefore conclusions lack internal validity.
• they do not use qualitative data therefore there is a lack of in-depth detail about the relationship