Why use a Wilcoxon’s? Answer

  1. Bianco and Lecce (2016) want to see whether the children who received the ToM intervention have made significant progress over the course of project by comparing their scores before and after the intervention. They have decided to use a Wilcoxon’s test. Explain why a Wilcoxon’s is a suitable test choice for them. (3)

The Wilcoxon’s is a suitable choice for this aspect of Bianco and Lecce (2016)’s analysis because they need a “test of difference” as they are comparing two conditions (before and after the Theory of Mind intervention) not looking for a correlation between pairs of scores.

Also Bianco and Lecce (2016) have  used a repeated measures design whereby the same children are tested before and after the intervention as opposed to an independent measures design with different children in each condition.

Finally, the data is ratio level (e.g. each child receives a score from the standardised Theory of Mind test scored from 0-120) which can be collapsed to ordinal data via ranking.