Question: How do you choose to argue? Educators frequently lament weaknesses in students' oral and written arguments. In Thinking and Reasoning (October 2006), researchers at Columbia University conducted a series of studies to assess the cognitive skills required for successful arguments. One study focused on whether students would choose to argue by weakening the opposing position or by strengthening the favored position. (Example: You are told you would do better at basketball than soccer, but you like soccer. An argument that weakens the opposing position is ‘‘You need to be tall to play basketball.''

An argument that strengthens the favored position is ‘‘With practice, I can become really good at soccer.'') A sample of 52 graduate students in psychology was equally divided into two groups. Group 1 was presented with 10 items, where the argument always attempts to strengthen the favored position. Group 2 was presented with the same 10 items, but where the argument always attempts to weaken the nonfavored position. Each student then rated the 10 arguments on a 5-point scale from very weak (1) to very strong (5). The variable of interest was the sum of the 10 item scores, called total rating. Summary statistics for the data are shown in the table. Use the methodology of this chapter to compare the mean total ratings for the two groups, at α = .05. Give a practical interpretation of the results in the words of the problem.

                                            Group I                                           Group II

                                 (Support Favored Position)                (Weaken Oppoing Position)

Sample size                                26                                                  26

Mean                                         28.6                                               24.9

Standard Deviation                       12.5                                               12.2