At my school GenChem is a requirement for all students. Thus, most incoming freshmen take Chem 1 in the fall and Chem 2 in the spring. It should not be a surprise, then, that most people who are taking Chem 1 in the spring are those who failed it the first time around. (We do have a number of students who transferred in mid-year, but these are definitely in the minority.)
I am in the middle of grading my first set of lab assignments, and it’s become glaringly obvious why many of these people failed: they can’t follow directions! The assignment was, I thought, very simple:
- Given a set of measurements for area and radius (created by a randomizer–everyone had a different set of data), use Excel to create a value for radius squared. Use Excel to create a series of values for pi (A/R^2).
- Calculate the average, standard deviation, and confidence interval for these values.
- Graph A vs. R^2. Use Excel to calculate a linear regression. The slope of this line should be pi.
- Compare the two values for pi. Tell which method you think is better, and why.
Note that I specifically told them, “If you don’t know how to use Excel, please stay after class so I can show you. Or come to my office hours.” No one asked for help. And yet, I’ve seen the following:
- Students who must have done all the calculations on their calculator, then entered the answers into Excel. The numbers are right, but no formulae are present.
- People graphing weird things: value of pi vs. area, radius vs. area, or (my favorite) value of pi calculated vs. measurement number
- Graphs which are not scatter plots (line graphs are most common), some of which have no linear regression done. How did they come up with a value of pi for this? I have no idea, but it’s written below the graph.
As one of the professors said during our last meeting: “And these people are going to be designing our bridges in ten years?!! Kind of scary!”