IB Psychology IA HL Exemplar: Results (Inferential)

Set out below is an example of a Results (Inferential) section of an IB Psychology Internal Assessment for Higher Level.

Results (Inferential)

As the experimental design was independent samples, and we could not be certain of a normal distribution around the mean, our quasi-interval data was ranked as ordinal and the non-parametric Mann-Whitney U-test of statistical significance was applied.

For n₁ = 10 and n₂ = 10, the critical value of U is 27 for a one-tailed test at the p < 0.05 level. To be significant, the calculated U has to be equal to or less than this critical value. The calculated U was 28.5 (see Appendix H) and therefore the difference between the two groups was not significant. The null hypothesis, that any increase in recalled words from the 25-word list written in a disfluent (italicized) font will not be significant, and will be due to chance, must be accepted. There was no significant increase in words remembered by Group A (disfluent condition).