Survey research and design in psychology/Tutorials/Correlation/Correlations and non-linear relations
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Four sets of data with the same correlation of 0.816
Correlations and non-linear relations
The purpose of this exercise is to emphasise the importance of visualising bivariate relationships to check whether a linear correlation best represents the patterns in the data.
* Correlations between 4 pairs of variables. CORRELATIONS /VARIABLES = x1 y1. CORRELATIONS /VARIABLES = x1 y2. CORRELATIONS /VARIABLES = x1 y3. CORRELATIONS /VARIABLES = x2 y4. * Scatterplots between 4 pairs of variables. GRAPH /SCATTERPLOT(BIVAR)=x1 WITH y1. GRAPH /SCATTERPLOT(BIVAR)=x1 WITH y2. GRAPH /SCATTERPLOT(BIVAR)=x1 WITH y3. GRAPH /SCATTERPLOT(BIVAR)=x2 WITH y4. What do the linear correlations and bivariate scatterplots indicate about the relationship between the following pairs?
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