Knight Physics for Scientists and Engineers

In the discussion of the lower FCI scores seen by students taking the Matter and Interactions curriculum on the PHYS-LRNR mailing list (see here for my department's experience), there were some people who made the claim that students do not read the textbook, and therefore the textbook should not have as much of an impact as the classroom engagement. I can't speak for other schools, but we have seen a very large change in FCI scores when we have changed textbooks.

The lower scores with the M&I text that we saw mirrored those reported in the AJP paper that started the discussion, but we also saw a very large uptick in scores in 2006, when we began using Randall Knight's Physics for Scientists and Engineers.

Before 2006, different instructors used different texts (Serway, M&I, Fishbane). In 2006 we decided to unify the textbooks, and we chose Knight largely because it was advertised to be strong in PER approaches and providing conceptual understanding. At the same time, we moved from homework submitted on paper to homework done on the Mastering Physics online system that can accompany the Knight text.

Whether the change can be attributed to the text, or to the online homework, there was clearly a change in the normalized gains our students had. Looking at individual instructors shows that the improvement was universal.

Instructor A (above) teaches with clicker questions and group problem solving. He pushes conceptual understanding (often using Ranking Tasks  in class) before equation solving. While his gains were near 0.4 with the Serway text, they increased with the Knight text, and now fell dramatically the one semester with M&I.

Instructor B (above) teaches with more demonstrations than the rest of the department. They are often done in ILD format. His results with the Serway text were more mixed, but the Knight results are very consistent, and higher than most of the Serway results.

Instructor C teaches with a lot of questioning of the students, but does not follow many other PER suggestions. Although he recognized that the Knight text had much more conceptual material than most texts, he opted not to change the material he covered (continued his "standard treatment"). He, too, saw an impressive increase.

All three instructors created their own homework assignments. Some were due weekly, others every other day. As mentioned above, the three instructors had vastly different teaching styles and approaches. The consistent elements were the Knight textbook and Mastering Physics. Whether it is one, or the other, or the combination, it seems clear that the choice of text and/or homework system can make a large difference in results.

FCI and Matter and Interactions

The July 2012 issue of the American Journal of Physics has an article that compares Force Concept Inventory (FCI) scores between a traditional section of introductory mechanics and one taught using the Matter and Interactions (M&I) textbook. The finding was that the post-test scores were higher for the traditional curriculum than for the M&I textbook, even though both were taught using similar interactive methods.

That finding mirrors what we have seen in our department. Three separate instructors have used the M&I text (1st edition once, 3rd edition twice), and all have had lower normalized gains than other sections taught that semester.

There is a lot of data there, but one instructor in particular has taught the introductory mechanics out of three different textbooks, using generally the same interactive techniques ("clicker" questions, group problem solving) with each text, and the results on the FCI with the M&I text were significantly lower.

As a department we made the change to M&I two years ago because we were seeing students coming in with more and more physics background. M&I provides the students with a different approach than they would have seen in high school, so it seemed less repetitious to our best prepared students. We also appreciated the introduction to computer modeling with VPython that is easily associated with M&I. In two more years, when the first batch of M&I students have made it through our entire curriculum, we will have to decide whether the seeming reduction in conceptual understanding (at least as measured by the FCI - and the CSEM for the E&M semester) is appropriately balanced by other M&I benefits (computer modeling, best prepared students remaining more engaged, etc.)

They said it better

My last post suggested that Khan Academy is not an enemy to education because it does not meet the highest standards of pedagogy and content. Rather there are increased expectations that are being placed on it with its increased popularity in the news and sponsorship from the Gates Foundation and Google.

Shortly after that post I read two pieces that said much the same thing. On was written by Robert Talbert in the Chronicle of Higher Education, and an agreement with that article here.