When teaching Statistical Methods, I use a skill-based approach. Many of my students don’t have plans to go to graduate school. Rather than emphasizing formulas, I teach my students the concepts behind the formulas. This teaches the key concepts from class, without overburdening them with complex formulas and symbols that often intimidate students.
One of my favorite activities that exemplifies this is used throughout the semester in my course. In this simple activity, students first learn how to calculate the standard deviation, then z-scores, and finally a correlation.
At the beginning of the semester, when students are learning the standard deviation, I use a table of raw scores to demonstrate how it is calculated. In the table below, you’ll see that there is a list of raw scores. Using those raw scores, students work their way through calculating the average, deviations, squared deviations, and finally the standard deviation. You’ll notice at the bottom of the deviations column there is a blank box for them to calculate the average of the deviations. This is useful for two reasons:
This table is simple for students to follow, and helps them remember the various steps involved in calculating the standard deviation.
A week or so later, students use the same table to calculate z-scores. They follow the same steps, working from a list of raw scores, and eventually transforming those scores into z-scores. By using the same table, students are able to see how what they have learned before about averages and standard deviations apply to z-scores.
Then, when teaching students about correlation and regression, I use the same table to demonstrate how to calculate r. Calculating a correlation can seem daunting for students. However, at this point, students have used this table numerous times in class and in practice problems at home. Using this table to calculate r puts a complex, intimidating topic in familiar terms. And the process is the same! But instead of calculating the SD and z-scores for one list, they calculate it for both X and Y. Then, all they need to do is calculate the cross-product of the z-scores, and average those cross-products.
These tables are simple ways for students to practice difficult topics. And not only is this simple for the students, it is also simple for the instructor! All you need to do is generate random numbers for students to calculate, and paste them into the column for the raw scores. I’ve included examples of the tables throughout this post. I’ve also linked to a couple handouts I use in my classes (see the links below). Please use and adapt responsibly :)
Karly's Handouts for (mostly) Formula Free Statistics
Calculating the standard deviation
Calculating the SD and z-scores
Calculating the correlation coefficient
Thanks for following The Novice Professor this week as we all shared our favorite in class activities. Check out the previous posts from Ciara (about how her students learn about personality traits through songs), Brian (where he talks about using The Office in Intro Psych) and a guest post from Kathryn Narciso (where she demonstrates how she teaches students about culture in the workplace) to learn about more of our favorite class activities!
Written by Karly Schleicher