corellation Flashcards
What is correlation?
Correlation is a technique for analysing the strength and direction of the relationship between two variables, known in correlation as co-variables.
This will show either a positive, negative or no correlation. This is shown with a rating from 1 to -1 , which mean positive or negative. The closer it is to 0 the more likely there is no correlation.
correlation evaluation
+) you can establish the strength of a relationship between two variables precisely.
+)Once correlations has been found you can predict about one variable based on the other.
+) you can investigate things that cannot be manipulated in an experiment for ethical or practical reasons.
- )Correlation analysis can not show cause and effect.
- )Even if there is a clear correlation it could be caused by an unknown third variable which affects both
- ) Correlation doesn’t measure curvilinear relationships only linear relationships, curvilinear relationships are bell curve relationships.
differences between correlations and experiments
An experiment isolates and manipulates an independent variable to observe its effect on the dependent variable, the environment will be controlled so extraneous variables are eliminated, experiments also establish cause and effect.
A correlation identifies variables and looks for a relationship relationship between them, there is no independent variable but two co-variables. They cant predict cause and effect.