Statistical nugget #1: ALWAYS check your continuous variables for normality before running any statistical analyses. An outlier, defined as any observation that is more than 3.29 standard deviations away from the mean of your continuous variable, will artificially inflate or deflate your t-values. Use skewness and kurtosis statistics to assess the assumption of normality for each continuous variable in your dataset. Visit www.scalelive.com/statistics-engine.html to learn more about normality and running these analyses in SPSS.