I have some ideas concerning a PER textbook. I will make some references to Giancoli's Physics (1998), which seems to be quite popular high school and algebra-based introductory physics book. I use the book in the International Baccalaurete (IB) program.
1) Exercises
Giancoli's exercises are very traditional problem solving exercises. There is nothing wrong with traditional exercises as such; I think that students need to practise formulas as well. Of course this is not sufficient. Giancoli offers conceptual exercises in the Questions-section. These can be used to complement traditional exercises. They are most likely useful but I am afraid that it will implant kind of split way of seeing physics exercises: quantitative (= formulas) and explanation questions which don't seem to have much connections.
A better way, in my opinion, is using problems which include both quantitative and qualitative aspects at the same time. Especially important is incorporating multiple representations: graphical, diagrammatic, verbal and mathematical (symbolic and vectorial). These tools should be developed and used systematically throughout the text and exercises. Sometimes I develop Giancoli's exercises further by adding extra tasks which demand multiple representations. This way students gradually gain a richer and more integrated understanding of physical phenomena.
There are some very good sources of conceptual exercises available: for instance Ranking Task Exercises (O'Kuma et al 2000) and Homework and Test Questions (Arnold Arons 1997). These exercises provide excellent material for collaborative discussions. I would like to see similar exercises in a PER textbook as well.
Data-based problems are almost completely absent from Giancoli. Finnish textbooks have them and I find them very useful for several reasons. Firstly they help develop graphical skills and related data analysis. Secondly they allow discussion of error/uncertainty sources if enough information is provided about experiments. Thirdly they give good opportunities to discuss underlying physics and add conceptual questions related with the experiments.
2) Data analysis
I guess that most intro courses have a lab component in which data-analysis is introduced. This applies to the IB courses as well. It would be very useful to have a short introduction on:
- error and uncertainty (this is included in Giancoli)
- linear graphs: estimation of uncertainty of a slope and a y-axis intercept (best fits and worst fits)
- simple rules for propagation of error
Perhaps this could be handled within few pages in an appendix. A teacher could then provide more details. A notion of graphical calculators could be made as well. Before using graphical calculators in data analysis I make sure that the students know how to do it manually. Graphical calculators can be used to illuminate some physics topics as well: e.g. superposition and beats.
3) Some ideas related to physics topics
a) Newton's Laws
I believe that the idea of interaction is crucial in forming the Newtonian understanding of the force concept. Students need an appropriate tool which helps them to gain familiarity with interactions. I have used SRI diagrams (Symbolic Representations of Interactions, Jim´enez-Valladares and Perales-Palacios 2001) before introducing free-body diagrams. I have had very positive results by emphasising interactions in the very beginning of the teaching of the Newton's laws. Modeling method System Schemas which also shows very clearly interactions (Turner & Politano 2001). Perhaps the SRI or System Schema tool could be introduced in the PER textbook?
b) Work and heat
I know that there are many physicists in this list who do not agree but I'll give my opinion anyway :-). I like the approach which treats work and heat as processes i.e. transfer of energy. Heat is defined as transfer of energy due to temperature difference and work as transfer of energy via forces. Knight (2001) develops these ideas nicely, especially work. Sprang & Verdonk (1994) give a thorough analysis of the approach.
It may well be that heat and work have to be redefined in more advanced courses (well, definition and redefinition is what Arnold Arons recommends). I hope that this does not start a new avalanche of postings concerning heat and work!
4) Concept maps as a revision tool
Giancoli has end-of-chapter summaries. There is nothing wrong with them but I believe that concept maps provide a better way to relate concepts in a meaningful way. I provide my own concept maps for revision. After some practise students learn how to use them and they start requesting the concept maps in the beginning of the course! Of course this does not prevent using student generated concept maps as well.
5) Instructor material
Many textbooks provide instructor's solutions manuals. I think that it is an asset because it reduces teachers' work load. There is also another reason: it helps teachers to present correct solutions with physical reasoning, especially if a PER textbook has conceptually demanding exercises. For a new teacher it may not be easy to do it without any help.
Another set of materials could contain references to essential PER papers - with URL's when possible - or even the papers themselves. And of course information about research-based conceptual inventories such as FCI, MBT, TUG-K and DIRECT (perhaps Bob Beichner could directly provide the tests which he has produced). All the material could be easily distributed via CD ROMs for instructors who adopt the textbook.
Arons, A. (1997). Teaching Introductory Physics. John Wiley & Sons, USA.
Giancoli, D. (1998). Physics - Principles and Applications, 5th edition. Prentice Hall International, USA.
Jim´enez-Valladares, J. & Perales-Palacios, F.J. (2001). Graphic representation of force in secondary education: analysis and alternative educational proposals, Physics Education, Vol. 36, Number 3, pp. 227 - 235.
Knight, R. (1997). Physics - A Contemporary Perspective. Addison-Wesley, USA:
O’Kuma, T., Maloney, D. and Hieggelge, C. (2000). Ranking task exercises in physics. Prentice Hall, USA.
Roon P., van Sprang H. and Verdonk A. (1994). ‘Work’ and ‘Heat’: on a road towards thermodynamics. Int. J. Sci. Educ., Vol. 16, No. 2, pp. 131-144.
Turner and Politano, M. (2001). System Schemas. Online at
<modeling.la.asu.edu/modeling/SystemSchema.pdf >