Review
John L. Hubisz, Ph.D., Hubisz@unity.ncsu.edu
and the reviewers of the Second Report.

Prisms Plus (2005) by Roy Unruh et.al. and published by Centre Pointe Learning http://www.cplearning.com/ppevotop.htm. Also see http://www.uni.edu/prisms/PRISMSPLUSfeaturesedited_s02.pdf for a detailed description of the material and the philosophy.

Another View
(see the original review)

Prisms Plus is a series of books and resources that provide a coherent, guided-inquiry physics curriculum that may be used in a Physics First program. In their own words Prisms Plus "utilizes an enhanced learning cycle pedagogy in which students engage in explorations prior to the introduction of abstract concepts. After the concepts have been introduced with the context of these explorations, students are then provided with additional activities that are opportunities to apply what they have learned to real-life experiences."

There are four texts/units: Force and Motion, Work and Energy, Waves and Optics, and Electricity, Magnetism, and Modern Physics. Instead of modules, PRISMS PLUS is designed around self-contained "Learning Cycles." Each cycle contains three types of activities: exploration, concept development, and application. There are 44 total cycles, designed to cover a one-year course. The cycles range from basic Kinematics to Radioactivity and the authors describe many different types of courses, of varying lengths, that can be designed using the same materials.

Of special note are the teacher texts that accompany the student volumes. These are universally excellent in their layout. In addition to teaching strategies for each learning cycle, they include a scorecard that lists the difficulty of separate components of each learning cycle, including lab setup, calculations, lab time, as well as the process and reasoning skills that the cycles are designed to address. The scores for each module are themselves socially constructed; they represent votes by high school teachers who have used the texts.

The NSE Standards and Scientific Literacy Benchmarks addressed by each cycle are also listed.

Readability: The student editions are closer to workbooks than textbooks, and their readability must be appraised differently from a more standard text. The concept section of each cycle is where most of the expository writing appears. The writing seems appropriate for the age group desired. The writing style is conversational, with frequent referrals to the reader (as in "you have noticed by now that ...")

The Prism books are definitely not "busy," even in the conceptual section. They are pretty sparse, and I believe that the writing is engaging. There is some hard evidence for this: for the scorecard given with each cycle, the Interest is ranked as good or excellent for most of the cycles (recall that these rankings are developed by teachers using these texts)

The writing in the other sections of the learning cycles includes lab directions, or open-ended questions that encourage the students to hypothesize and/or apply their newly-constructed knowledge to other situations. Most of these questions/directions are sparsely written. The economy of words here is OK, although the role of the teacher in setting the stage for these sections, and guiding the students through their inquiries, is crucial to the success of these texts.

Mathematics Requirements: One striking feature of the Prisms Plus texts is that there is very little mathematics displayed. Other than worked-out arithmetic (e.g., when calculating an average velocity), there is an occasional formula (kinematics, e.g.), and a lot of graphs. Of course, mathematics is needed to solve many of the homework problems in the text. But certainly the mathematics level should be appropriate for first-year high school students.

The cycle scorecard is revealing here: most of the Learning Cycles are described as having easy or moderately difficult calculations. Only a very few are rated as difficult calculations (e.g. a calculation of center of gravity)

Accuracy: I have only read the first cycle in each text closely, and, because there are 40-plus other Learning cycles, l am reluctant to criticize the Prisms series as a whole. That said, I have found a number of issues - from conceptual approach to unclear wording to errors - that teachers should be aware of when using these texts. It is especially important to note that some of the errors appear in the teacher version of the text when discussing how to explain material to the students.

I include here a summary of some of the issues that I found in just the first few pages of Book 1: The Kinetics Learning Cycle.

Although I did not come across any calculations that were in error, I did find a number of discussions that contained wording or concept usage that was quite different from what I am used to. I realize that the target audience is young high school - even middle school students. However, some of the concept presentations may reinforce misconceptions that many students will take with them to more advanced physics and other science courses.
For example, even though the text defines displacement appropriately as a change in position with respect to some reference, the lab activity has the students measure the Total Displacement of a moving cart and plot this vs. time to yield a Displacement vs. Time graph rather than a Position vs. Time graph. This non-standard approach (when compared with traditional texts) may lead to misconceptions and lost opportunities for teachable moments with this and future material.

Ultimately the students calculate the average velocity as a change in displacement in time as opposed to a change in position vs. time. Obviously, they come up with the same answers as if they had used position-time data, but I question whether this usage might not cause problems down the line. If taking a college physics course, students will see Position-time graphs, and will calculate displacements from these graphs, as opposed to graphing the displacements. Especially when these texts define in the standard way as delta-v/delta-t, using velocity as delta-d/delta-t is actually a "double delta" because displacement is actually a "delta-position." Why not stick with velocity as delta-position/delta-time?

Ordinarily I wouldn't worry so much about this displacement-centric approach, and take it as an alternative approach that yields the same answers, and may actually be better for the students in early high school. However there is notational inconsistency between the students and teacher texts. In the student text, delta-d is used for displacement (p. 3), while in the Teacher copy, d is used for displacement and delta-d is used for change in displacement. (p. 7)

While this discrepancy may be addressed in the next edition, teachers using these texts should be aware of a deeper conceptual issue in using the displacement-centric approach.

When plotting total displacement vs. time, there is now a time-interval associated with each point, namely the time from the reference point to the time at which the total displacement is measured. (There is even mention of an 'interval of displacement" in the Teacher edition - see p. 8). Because of this, the ratio of each point's vertical and horizontal coordinate now yields an average velocity (from the reference point). While this is not pointed out in the text, the very fact that it is possible to make this calculation and interpretation means that the method of using slopes of secant lines to calculate average velocities may be viewed as "harder" because two points are involved in the calculation.

The use of displacement as opposed to position when measuring velocities in an early introduction to kinematics may be a personal preference. There are a few errors, however, that appear in the Kinematics Learning cycle that are important to keep in mind if these texts are adopted:

On page 2 of the Teachers edition the authors describe vectors adequately, and then go on to say that the teacher needs to "make sure that students recognize that negative acceleration is what they know as deceleration." This statement is at odds with the vector nature of velocities, and, is a classic misconception that students bring to an intro physics course. In fact, several traditional textbooks go out of there way to say the opposite, i.e. that deceleration and negative acceleration do not mean the same thing.

On page 12 of the Student edition of Forces, the students are given a displacement-time graph and asked "in which part of the graph is the object accelerating?" The graph itself is made up of straight-line segments followed by a smoothly varying segment. The acceleration is happening at every change of straight-line section, plus over a region of the smooth curve that clearly displays some curvature. Because of the way the question is worded, students may think that acceleration only occurs at one place. This misconception may be confirmed by the teacher because the Teacher's edition mentions only one spot where acceleration occurs.

Occasionally, the examples used in the text are more sophisticated, leading to bigger "wow" factor, and probably help to make the physics more meaningful. However the need to keep the analysis simple again may lead to serious misconceptions. A specific case is the skateboard example on page 9 of the student edition, which describes a skateboarder moving down a hill, up another hill, then rolling back down the second hill. This is 2-D motion, but it is treated as 1-D. A graph of velocity vs. time is shown that is clearly a graph of the horizontal component of velocity, with the sign of the velocity defined in the following way: "motion away from you will be positive and motion toward you negative." The graph is consistent with this definition as long as the motion away is taken only to mean horizontal motion away. An acceleration graph is then produced which is also correct for this interpretation. Naturally, there are points in time at which the horizontal acceleration is 0. While technically everything is OK, the need to keep the analysis to 1-D, presumably because of the student sophistication, could lead to the error often made in projectile problems, or indeed any problem involving vertical motion: the notion that vertical acceleration is zero when in fact it is always present as g.

In the effort to make the text readable, and conversational in style, there is the occasional ambiguous wording. On page 8 of the student edition the ideas of a non-linear displacement vs. time graph is developed. The passage begins "most motion usually does not continue in a straight line indefinitely", and a non-linear graph is displayed. However, it is a graph of 1-D motion, and therefore the graph is a display of an object moving in a straight line, only at varying speeds. I believe that the authors are mixing up the motion itself with the graphical representation of the motion, i.e. when there reference to "straight line" in their description refers to a linear displacement-time relationship.

I found similar ambiguous wording in the Work and Energy text. Ironically, one case occurred when the authors pointed out the need to avoid sloppiness in definitions. After a discussion of how some words/phrases we often use in everyday conversation have a different context in physics, they then describe the work done by a force in the standard way. Yet they then give an example of climbing stairs, using the language "you are doing work by transferring energy from your muscles" into a gain of potential energy. I.e. the connection of work to the force actually doing the work, a common problem for students, is confused from the beginning.

In an experiment in the same cycle, students measure displacement up an inclined plane for a set of different angles of inclination, keeping the vertical height of the plane constant. The text describes this as a way to get different displacements "along the hill". Clearly, because of the different angle of inclination, the students were looking at different hills.