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Annotated Output | Paired Samples t Test

Computer Output

The table of descriptive statistics can be used to determine the inferential statistics.

Summary Statistics for the Data
               N       M      SD    Skew    Kurt
Outcome1   4.000   2.000   2.449   0.544  -2.944
Outcome2   4.000   6.000   2.449   0.544  -2.944

The descriptive statistics are calculated separately for each instance (which are shown as separate variables).

The tables of inferential statistics show the key elements to be calculated.

Confidence Interval for the Mean Difference
              Diff      SE      df      LL      UL
Comparison   4.000   1.225   3.000   0.102   7.898

Hypothesis Test for the Mean Difference
              Diff      SE      df       t       p
Comparison   4.000   1.225   3.000   3.266   0.047

Confidence Interval for the Standardized Mean Difference
                 d      SE      LL      UL
Comparison   1.633   0.782   0.101   3.165

Here, t = 3.266 and p = .047. This would be considered a statistically significant finding.

Using “CI for Mean Difference”, the researcher estimates that the true population mean difference is somewhere between 0.102 and 7.898 (knowing that the estimate could be wrong).

Cohen’s d = 1.633. Given Cohen’s heuristics for interpreting effect sizes, this would be considered an extremely large effect.

APA Style

For this analysis, the differences between two measurements on one set of people are being compared. Thus, the summary and the inferential statistics focus on that difference.

A paired samples t test showed that the difference in Outcome scores (N = 4) between the first time point (M = 2.00, SD = 2.45) and second time point (M = 6.00, SD = 2.45) was very large and statistically significant, t(3) = 3.27, p = .047, 95% CI [0.10, 7.90], d = 1.63.

Alternatively, the means, standard deviations, and confidence intervals could be presented in a table or figure associated with this text.