Mozart and manual dexterity. A researcher is interested in the effect of music on the performance of tasks requiring manual dexterity. She chooses playing Symphony no. 41 (the Jupiter Symphony) by Mozart as background music and playing no background music as treatments. The response variable is the time it takes to accurately cut out a complicated pattern on a piece of paper with scissors.

Chapter 6 Exercises 119

(a) Outline a completely randomized design to compare dexterity at the different treatments. Twenty subjects are available.

(b) Because individuals differ greatly in dexterity, the wide variation in individual scores may hide the systematic effect of presence or absence of music unless there are many subjects in each group. Describe in detail the design of a matched pairs experiment in which each subject serves as his or her own control.

AppendixLO1