4- correlations

Correlation

A research method that measures the relationship between two variables without manipulating them.

Correlational analysis

A statistical technique used to identify the strength and direction of a relationship between variables.

Positive correlation

A relationship where as one variable increases, the other also increases.

Negative correlation

A relationship where as one variable increases, the other decreases.

Zero correlation

No relationship between two variables.

Correlation coefficient

A numerical value between -1 and +1 that indicates the strength and direction of a correlation.

Scattergram

A graph that shows the relationship between two variables using plotted data points.

Strength of correlation

How closely data points cluster around a line of best fit.

Direction of correlation

Whether the relationship is positive or negative.

Strength of correlations

Allow researchers to study relationships where experimental manipulation would be unethical or impractical.

Strength of correlational research

Can identify relationships that can be used to generate hypotheses for future experiments.

Strength of correlations using large data sets

Increases generalisability due to larger samples.

Correlation does not equal causation

A correlation cannot show that one variable causes changes in another.

Third variable problem

A separate, unmeasured variable may be responsible for the relationship between two variables.

Weakness of correlations

Lack of control over variables reduces internal validity.

Why can correlations not establish cause and effect?

Because variables are not manipulated and extraneous variables are not controlled.

When are correlations useful in psychology?

When investigating relationships that cannot be experimentally tested.

How are correlations visually represented?

Using a scattergram with a line of best fit.