In a classic study, Shrauger (1972) examined the effect of an audience on performance for two groups of participants: high self-esteem and low self-esteem individuals. The participants in the study were given a problem-solving task with half of the individuals in each group working alone and the other half working with an audience. Performance on the problem-solving task was measured for each individual. The results showed that the presence of an audience had little effect on high self-esteem participants but significantly lowered performance for the low self-esteem participants. 

a. How many factors does this study have? What are they?
b. Describe this study using the notation system that indicates factors and numbers of levels of each factor. 

c. Use a matrix to diagram the structure of the study.