correlations

Question 1

how do correlations differ from experiments?

Answer 1

• variables are measured, not manipulated
• only an association is found, no cause and effect relationship is established

Question 2

what is a negative correlation?

Answer 2

when 1 variable increases, the other decreases
- negative gradient on scattergram
- correlation coefficient of less that 0

Question 3

what is a positive correlation?

Answer 3

when 1 variable increases, the other variable also increases
- positive gradient
- correlation coefficient of more than 0

Question 4

what is zero correlation?

Answer 4

no relationship found between co-variables
- no line of best fit can be drawn
- correlation coefficent of 0

Question 4

give 3 limitaions of correlations

Answer 4

• hard to establish a cause and effect relationship
• third variable problem is increased
• correlations are often misued by media

Question 4

give 3 strengths of correlations

Answer 4

• quick and economical to carry out
• secondary data can be used so less time consuming
• can be used as starting points to assess patterns between co-variables before committing to an experiment