The mean of the **midterm exam** was 71.6, with a standard deviation of 12.7. Here are some comments from Nate Rockwood, who graded the exams:

- People tended to do worse on the logic questions, especially in sections 1.1 (on average only 59% correct) and 1.2 (on average only 65%). Everyone except for one student, for example, got 1.1 question 6 wrong. Lots of people got 1.1 question 3 wrong as well.
- In section 1.4 question 2, there was a surprising number of people who thought the argument was invalid (it is in fact Modus Tollens).
- The students tended to well on the last section.

**Paper 1:** The class mean was 6.75, with a standard deviation of 1.51, and with scores ranging from 5 to 9. Students tended to struggle with explaining what the statistical significance is measuring. Several, for example, claimed that the low statistical significance showed that there was not a strong correlation between the variables. But it is quite possible to have a strong correlation and a relatively low statistical significance.

On the positive side, many students argued that there may be other, more causally relevant, variables that are more reliable predictors of future success than college writing. This is a good argumentative strategy, so long as it is clearly explained why the boss should not put too much trust in the study being cited.

Comments on individual papers can be viewed through turnitin.com, where you will also find your grade. Highlighted text is purple to indicate that a good point is being made, and yellow for a problematic statement.

**Paper 2:** Students did better on average on the 2nd paper, which is encouraging. The class mean was 7.25, with a standard deviation of 0.95, and with scores ranging from 6 to 8.5.

Many students were not clear about what kind of study they were proposing. Students should explain clearly whether they are proposing an experimental or observational study. And if they propose an observational study, they should be clear about whether it is a prospective or retrospective study. For example, if I were proposing a retrospective observational study, then I would explain what the structure of a retrospective observational study is, how I would apply it in this case, and why I think this is the most appropriate kind of study for this scenario.

**Final exam:** the mean was 48.9 points, with a standard deviation of 10.6. You should get your final grades for the class very soon.