Computer Labs

Computer Lab 1: One-Way between Groups ANOVA

Descriptive Statistics

Means:

• Placebo: 4.15 (1.14)

• Drug A: 4.00 (1.34)

• Drug B: 6.90 (.97)

Medians:

• Placebo: 4.00

• Drug A: 4.00

• Drug B: 7.00

IQR:

• Placebo: 1.75

• Drug A: 2.00

• Drug B: 1.75

Tests of Normality:

• Placebo is normally distributed because p = 1.00 (Shapiro-Wilk because N < 30), which is more than .05

• Drug A is normally distributed because p = .07 (Shapiro-Wilk because N < 30), which is more than .05

• Drug B is normally distributed because p = .08 (Shapiro-Wilk because N < 30), which is more than .05

Homogeneity of variances is met because p = .23, which is higher than .05

One-Way ANOVA full report

a One-Way ANOVA was conducted to analyse the effectiveness of two treatments at reducing anxiety levels when compared to a placebo condition (Placebo, Drug A, Drug B). The assumption of normality was met upon inspection of histograms and Shapiro-Wilk (all p’s > .71). Homogeneity of variance was also assumed (Levene’s F(2, 57) = 1.52, p = .23). Results revealed there was statistically significant difference between the three conditions o mean anxiety scores (F(2, 57) = 39.80, p < .001)