Paired Samples Test Paired Differences t df Significance Mean Std. Deviation Std. Error Mean 95% Confidence Interval of the Difference One-Sided p Two-Sided p Lower Upper Pair 1 After - Before 1.30000 1.70294 .53852 .08179 2.51821 t= 2.414 9 .019 .039 Paired Samples Effect Sizes Standardizera Point Estimate 95% Confidence Interval Lower Upper Pair 1 After - Before Cohen's d 1.70294 .763 .037 1.458 Hedges' correction 1.86343 .698 .034 1.333 a The denominator used in estimating the effect sizes. Cohen's d uses the sample standard deviation of the mean difference. Hedges' correction uses the sample standard deviation of the mean difference, plus a correction factor. Biased conclusions would include... - the difference would be found in populations other than the one sampled - dieting causes weight gain (you need a control group to determine cause and effect; the pre-post differences may have occurred without dieting) - the difference is meaningful because t is statistically significant (meaningfulness is based on the effect size, or other information, not t) - the difference is statistically significant because the effect size is large (significance is based on t, not the effect size)