My problem is: I have a dataset of approximately 12000 people. In my analysis, I divided the entire sample into three different groups: Group A (n=6000), Group B (n=3000), and Group 3 (n=3000). I performed a multivariate analysis and we found 2 variables mediating the association. However, the reviewer have asked me to perform a confirmatory analysis creating three numerically identical groups of participants of different Groups but matched for major confounders (those 2 variables we found to mediate the association) and then test for differences in the dependent variable.

Is it possible to do this analysis using SPSS v22?

Thanks. ]]>

I'm a 3rd year Biology student and am investigating the effect of several factors on the number of bats that pass the detector device each night.

I have run a multiple linear regression with bat passes as the dependent variable, and temperature, night length, and temperature/night length interaction (temperature*night length) as independent variables.

The SPSS output gives me a 'Correlations' table and a 'Coefficients' table. I am really struggling to understand how for example passes and temperature have a statistically significant relationship under the correlations table, but are not statistically significant on the coefficients table.

If someone could please explain this to me in very plain layman's terms I would be extremely grateful.

Thanks so much. ]]>