Presenting the Results of an Independent Samples t test

Weight Loss

• Those who completed Program A lost significantly more weight (M = 22.67 lb, SD = 4.27, n = 6) than did those who completed Program B (M = 13.25, SD = 4.09, n = 12), t(9.71) = 4.469, p = .001, d = 2.269, 95% CI [.995, 3.50].

• If you are confident that pounds is a meaning unit for your audience, you could present the effect size statistics in unstandardized units -- 9.4 lb [4.7, 14.1].

Sex and IQ

• The mean IQ of girls (M = 101.8, SD = 12.7, n = 55) did not differ significantly from that of boys (M = 99.3, SD = 13.2, N = 33), t(69.7) = 0.88, p = .38, rpb = .093.

• Since the difference was not significant, direction of the effect was not emphasized.

Sex and Statophobia

• Women reported significantly more fear of the course(M = 6.55, SD = 2.16, n = 463) than did the men (M = 5.80, SD = 2.59, n = 161), t(241.3) = 3.32, p = .001, d = .33, 95% CI [.15, .51]

Red State, Blue State

• The mean income in states that voted for Kerry (M = $34,672, SD = 500, n = 20) was significantly higher than that of states that voted for Bush (M = $28,333, SD = 288, n = 31), t(27.2) = 5.14, p < .001, d = 1.65, 95% CI [.99, 2.29]

• If the audience was familiar with the dollar as a unit of income, effect size statistics could be reported in unstandardized units -- $6,339, [$3,881, $8,866].

• Mean IQ was significantly higher in states that voted for Kerry (M = 100.95, SD = 1.99, n = 33) than in those that voted for Bush (M = 99.26, SD = 2.42, n = 55), t(46.1) = 2.72, p = .009, d = .75, 95% CI [.16, 1.33].