Correlation

what is involved in an experiment and how do we use them?

• independent, dependent and extraneous variables (controlled)

• aims to establish the cause and effect giving the study internal validity

• they look at a difference in performance of two or more groups

what is involved in an correlations and how do we use them?

• instead iv/dv we measure co-variable

• no control is used therefore no cause and effect is possible

• correlations look at a possible relationship between co-variables

what is a correlational hypotheses?

states the strength of a relationship between two co-variables

• e.g. there is a relationship between the number of hours slept and the number of hours using a screen (non-directional)

what is a strength of correlations?

it suggests new areas to research scientifically

what are the weaknesses of correlations?

• no cause and effect relationship

• third variable may be affecting the relationship

what is a curvilinear relationship?

optimal level in the middle, drops off on both sides of the middle

what is a correlation coefficient?

• this is a number between -1 and +1 that tells us the strength and direction of our relationship

• it comes from using statistical tests

• the closer the number is to 1 the relationship is strong, the closer to 0 the weaker it is