Statistical Analysis for Education and Psychology Researchers

95

per

cent

CI

for

r—

8.13

Fisher’s z is
and the 95 per cent CI is

These values now have to be transformed back to the original metric.

Interpretation

We can conclude that we are 95 per cent certain that the population correlation is positive
and is in the interval 0.61 to 0.98. This confidence interval does not include zero which
indicates that the correlation is statistically significant at the 5 per cent level.

Computer Analysis

The SAS procedure PROC CORR with the option Pearson computes Pearson
correlations. Sums of squares and cross product sums of squares can also be requested
using the option CSSP. The relevant SAS code is:

proc corr data=a pearson csscp ;

var maths smaths raven;

run;

The variables to be included in the correlation analysis are specified with the VAR
statement. Output from this procedure is shown in Figure 8.9.
Correlation Analysis
3 VAR Variables: MATHS SMATHS RAVEN

Inferences involving continuous data 289