Kaarten: Methodology - Chapter 12 - The Correlational Research Strategy | Quizlet

Correlational research study

When two or more variables are measured to obtain a set of scores for each individual. The measurements are then examined to identify any patterns of relationship that exists between the variables and to measure the strength of the relationship.

Correlation, or correlation coefficient

A numerical value that measures and describes the relationship between two variables. The sign (+/-) indicates the direction, the numerical value (0.0 to 1.0) indicates the strength or consistency, the type (Pearson or Spearman) indicates the form.

A lineair relationship

A relationship where the data points in a scatter plot tend to cluster around a straight line.

Pearson correlation

A correlation used to describe and measure linear relationships when both variables are treated as numerical scores (interval- / ratio sales).

A monotonic relationship

A relationship that is consistently one-directional, either consistently positive or consistently negative.

Spearman correlation

A correlation used to measure and describe the consistency of monotonic relationships. It computes the correlation from ranks and inconsistencies in the size of increase / decrease are irrelevant.

A contingency table

A table that illustrates how the scores for one variable vary according to the scores of the other variable

Coefficient of determination

"A common technique for measuring the strength of the relationship between two variables. It is the squared value of a correlation and measures the percentage of variability in one variable that is determined or predicted, by its relationship with the other variable. Degree of relationship is:

Small r = 0.1or r²=1%

Medium r = 0.3 or r²=9%

Large r = 0.5 or r²=25%

The predictor variable

The variable that predicts or explains the other variable in a correlational study that demonstrates a relationship between two variables

The criterion variable

The variable that is predicted or explained by the other variable in a correlational study that demonstrates a relationship between two variables

Multiple regression

a statistical procedure studying multivariate relationships