Saturday, September 3, 2011

An Alternative Textbook

"Everyone complains about the weather, but nobody does anything about it."  This old adage seems appropriate for textbooks as well. Are textbooks too long, too heavy, and too expensive?  The textbook and associated materials are typically costing students up to $200 or more. This situation means many students would like to sell their textbook (a sad testament to the fleeting nature of knowledge these days) and many students never buy a book!  Other solutions seem to fall short. "Renting" books is touted as a great boon for students, but the rates are around 50% face value for several months ownership (compare to rates for leasing a car!), and also deprives students of the option of having a permanent record of their learning.

Additionally, there are serious questions about the pedagogical basis of textbooks.  If it is true, as Peter Atkins has claimed, that there are only 9 key concepts for General Chemistry students to acquire, we can ask: is it truly necessary to have over 100 pages per concept?  Where is the space and mental time for students to construct their own understanding, if they are at first confronted with the task of deconstructing a massive tome. It has been shown that collaborative learning models such as PLTL improve learning, but in large part these advances have not been incorporated into the thinking behind textbooks, and one has to adapt these practices to the text rather than let the pedagogy set the pace.

A larger point regarding textbooks and pedagogy is this: if it is true that many students do not buy textbooks because of prohibitive costs (see Chronicle of Higher Education article), then for those students the pedagogy of the text is a moot point!

The one big recent positive change for textbooks is the technology of online homework.  Evidence is accumulating that this is an effective tool in keeping students on task and improving understanding. So most textbooks come with databases of online problems, which allow instructors to assign problem sets to students and can get feedback on their performance.

In view of all of these concerns about textbooks I have, over the last 5 years, been developing and testing a different model for a textbook. Chemistry: Exploring the Molecular Vision is a "small footprint" text at about 500 pages. Each chapter includes: 

1.  Core readings in the traditional topics of General Chemistry.
2.  Links to online homework (Exploring Chemsitry Online, ECO).
3.  A workshop designed to accompany a two hour peer-led session.

The approach is an invitation to a new model of textbook in another sense as well: a collaborative model. Participants can provide real time feedback and review utilizing Google tools such as Google groups. Faculty can easily add/share problems for online homework using the Classmarker system, as well as develop and post animated powerpoints that can address interesting applications or explain concepts that require dynamic visualization.  Research on this new integrated model of PLTL can be shared.  The textbook can be empowering for faculty, opening up avenues for educational research.

If you are interested in this approach I hope you will take the time to view the Google presentation:

Chemistry: Exploring the Molecular Vision.  An alternative textbook

Thursday, June 16, 2011

The PLTL Boost

The PLTL Boost: A Critical Review of Research is an article in Progressions that summarizes the body of research studying the impact of PLTL on student success in STEM courses, and contributes a critique of statistical models that has a wide implications for future studies of student performance. The main points are:
  1. There are 15 published studies that represent introductory college science and engineering courses at 23 institutions that show an average increase of +15 % ABC for students participating in PLTL. 
  2. Three main types of implementations were identified: Type 1: a one to two hour peer-led workshop that replaces one lecture; Type 2: a one to two hour peer-led workshop that replaces a graduate student led recitation; and Type 3: an optional, added peer-led led workshop. All three types of implementation demonstrated similar impacts for participating students. 
  3. The studies used a variety of statistical models, from simply assuming a random distribution to more sophisticated multi-linear regression. It is shown that multi-linear regression has an inherent error when attempting to control for prior knowledge in the guise of such things as SAT scores. The result is that the impact of PLTL is underestimated for many students. An alternative, more robust model, is proposed: comparative linear regression, as describe in Zar (Biostatistical Analysis). 
If we adhere to the principles of Scientific Teaching, then the large body of work reviewed here should provide compelling evidence for those interested in student success to closely examine this straightforward adaptation of traditional teaching models.