Update on SC 130 Physical Science

Given that I am wrenching around with a general education core lab science course, I feel obliged to share what I am doing. Bear in mind that I am guided in my thinking by such documents as Project 2061 from the AAAS and other science curriculum reform materials. 1

Curriculum and Course Content

The course is increasingly focused on the laboratory. Monday begins with hand back and review of the laboratory that was due in on Friday. Laboratories are due eight days after the laboratory on Friday. Originally they were due at the next laboratory period, but the students consistently needed additional time and I do not mark laboratories until the weekend, hence the evolution of turn-in on Friday eight days after the laboratory.

On Monday I also hand back the most recent Friday quiz or test and go over that with the class. I continue to find these Friday quizzes to be very valuable in gaging student learning. The most recent quiz included questions that required answering by writing an explanation of a phenomenon seen in the laboratory the day before. The quiz also included drop-dead simple definitions from the laboratory and quantitative problems based on the text and laboratory material.

Monday is usually wrapped up with an introduction to new material, which continues on Wednesday. This remains the most "traditional" part of the course. The material introduced has been related to the laboratory on Thursday. I have a sense that two years down the road the course may look like a 16 topic exploration of physical science and science as process. Bear in mind that as currently built the course outline is 108 physical science factoids, and the text contains hundreds of concepts and equations. Little wonder the typical student sees science as lots of stuff to be memorized and to be taken on faith.

The catch is that the term I finally have an outline to submit to curriculum, the outline will likely look sparse, especially compared to the 108 factoid list of the present course.

Assessment results for this past week

Last week focused on momentum, both qualitatively and quantitatively. The quiz sought both reasoning and calculational answers. The item analysis for this quiz was:

i Src Q Description Corr Corr%
4 q03 1 define taw 26 90%
4 q03 1 define duck 24 83%
4 q03 3 qualitative marble momentum problem 28 97%
4 q03 4 qualitative marble momentum problem 27 93%
4 q03 5 hypothesize why marbles in equals marbles out in your own words 13 45%
4 q03 6 explain how speed in relates to speed out for marble momentum 11 38%
4 q03 7 given mass, distance, and time, find the speed 6 21%
4 q03 7 units 5 17%
4 q03 7 significant digits correct 5 17%
4 q03 8 given mass, distance, and time, find the mementum 6 21%
4 q03 8 units 2 7%
4 q03 8 significant digits correct 3 10%
4 q03 9 given a formula, plug-in masses, velocities to determine momentum con 19 66%
4 q03 9 units 7 24%
4 q03 9 significant digits correct 3 10%

Questions one and two related directly to the laboratory the day before and required only simple recall of the names of the different sizes of marbles. Students do really well at these simple single fact recall questions with 90% and 83% of the students answering these correctly. That there were three of twenty-nine that failed to absorb that a taw is a large shooter marble and five that missed out on a duck being a small marble suggests that there are some that really are paying any attention to anything going on in the laboratory. I would note that absences are not underneath this - attendance for laboratory included all twenty-nine who took the quiz. No student said a duck was waterfowl!

A line of duck marbles

Question three and four were based on the part one of the laboratory. In this section of the lab the students collided marbles with a line of marbles. That the number ejected always equaled the number which collided with the line proved puzzling to the the students once they considered the question, "How do the marbles at the end of the line know how many marbles hit the front of the line?" The students played with this simple system at length. During the laboratory some commented that it was a mystery, one noted that God told the marbles what to do. That 28 and 27 of 29 students answered these two questions correctly suggests the students remember well what happened.

Renee observes the effect of a single marble on the line of marbles.

When asked the anthropomorphic question, "Why do you think the marbles know what to do?" in question five the answers were much more revealing. Some students glued together almost random collections of scientific terms. Other students struggled to get ideas in their heads expressed, clearly trying to use scientific terms with meaning. Some showed remarkable insight into the marble system. This question is at the heart of what I am trying to do in the course - get the students to think about and wrestle with their physical world. What always surprises me is which student shows apparent insight and which is wandering lost in a sea of pseudo-scientific ideas.

One student who struggles in mathematics - something I'm keenly aware of from other courses she has been in - answered, "because the marbles are the same size with the same mass and if you roll one marble the mass of the marble will roll off only one marble." Another student who also struggles in mathematics noted, "Because of energy. The energy of the marbles that collide will pass through the line of marble and fill the last with the same energy and move the same energy of the marbles that collide will be move the last marbles." Although grammatically muddled, the sense that energy is passed down the line and energy in must equal energy out is very insightful.

Only four students objected directly to the anthropomorphic thrust of the question, one noting "I think they actually don't know what to do,..." Others took the anthropomorphic approach and ran with it, "The marbles know what to do because they feel the momentum among themselves." Another went further, "It's a mystery. The marbles know exactly how many to send. It's amazing. It's like they're speaking to each other. It's a scientific mystery." At least the student was amazed. Another noted, "I think that they know that if two in two will out. This means they they want to be in pairs."

Some confused terminology from other parts of the laboratory, betraying a deep underlying confusion. "Because potential energy is equal to kinetic energy." My own take is the student is grasping for scientific terms without understanding what they mean. Other students spoke of forces being passed by the marbles. All-in-all the answers provided tremendous insight into the ability of the students to wrestle their way through a concept that eluded humankind for thousands of years.

Performance on number six was strikingly low given that the answer was simply, "speed in equals speed out." I have a strong feeling the wording of the question was confusing, I want to follow-up on this on Monday.

Number seven was a classic "too many numbers" problem. I gave the students the mass of a marble and the time to cover a fixed distance, "A 20.2 g taw covered 30.0 cm in 0.59 seconds. What is the speed of the taw?" The mass information was spurious. The class has been working speed problems since laboratory number two, I thought the students would discern the spurious information and make the speed calculation. I was really wrong. Only six of 29 students got this correct. Looking through the answers our students appear to be almost pathologically addicted to using every number given in a problem. Turn off brain, multiply and divide everything in sight.

The same six who answered seven correctly would go on to answer eight correctly, "A 20.2 g taw covered 30.0 cm in 0.59 seconds. What is the linear momentum of the taw?" This problem uses all three numbers, or can be solved by multiplying the answer to seven by the mass. Note that question nine actually included the formula for momentum, so memorization of the formula was not necessary for a savvy quiz taker.

I only mark the units correct if the calculation is correct, so the item analysis for inclusion of units is always less than or equal to the number of students who got the calculation correct. In general, student performance on correct units is improving.

The ability to determine significant digits remains problematic. No student was ever taught the correct rule - that one keeps the same number of significant digits in the answer as one had in the original measurements. This does not mean that if one has two decimal places in the original measurements one keeps two decimal places, which is the rule most students learned. The complication is that few teachers of science know the correct rule or understand the theory underneath the correct rule. For those who want all the gory details I have prepared a paper.

The rule we use is simple - count the digits in the measurement, round to that number of nonzero digits. Despite this, old habits of keeping a couple decimal places no matter what die hard.

Laboratory Matters

The laboratory rubric was evolved again this week. I had eliminated the organization section, but too many laboratories are coming in as separate spreadsheet and word processing documents with sections in all kinds of order and disorder. Some labs even start with the conclusion. The new rubric is:

1. [h] Hypothesis/Prediction/Introduction (when given, not scored)
2 Clearly stated with any associations among the variables described
1 Unclear statement, or variables left unaccounted for
0 Omitted
2. [t] Data tables
2 Clear and complete, laid out clearly with labels and units
1 Missing one or more labels or units or other minor issues
0 Omitted or very unclear, confusing, poorly done, highly incomplete
3. [a] Data analysis
2 Appropriate statistics calculated and/or appropriate data analysis including units
1 Missing units or other minor issues
0 Omitted
4. [d] Data display: graphs and charts. None in lab 01
2 Complete and essentially correct
1 Incomplete or with errors such as the wrong graph type
0 Omitted
5. [c] Conclusions
4 Strong reasoning based on the data, logically reasoned, complete and thoughtful
3 Moderately well-reasoned, but tangential to the data or based on misconceptions
2 Overly brief or compromised and impaired by grammar and syntax errors
1 Unclear, not well reasoned, highly incomplete, or unusually weak
0 Omitted
[G] Grammar and Syntax
3 No errors of grammar or word order.
2 Some errors of grammar or word order but communication not impaired.
1 Frequent errors
0 Errors of grammar or word order so severe as to make comprehension virtually impossible.
[V] Vocabulary
3 Appropriate terms used consistently, clear command of vocabulary with a focus on correct usage of physical science vocabulary, no misspelled words.
2 Occasionally uses inappropriate terms or relies on circumlocution; expression of ideas not impaired; or a few misspelled words.
1 Frequent errors in vocabulary or spelling, ability to communicate limited by vocabulary
0 Vocabulary limitations so extreme as to make comprehension virtually impossible.
[O] Organization
3 All sections present in the right order
2 One section missing or out of order
1 Multiple sections out of order, or turned in as separate spreadsheet and word processing docs
0 Only one section or no sections apparent.
[C] Cohesion
3 Ideas flow logically. Connector words assist the reader.
2 Ideas are disconnected and the conclusion reads more like an outline or answers to a list of questions without connector words. There is a choppy and disjoint sense to the writing style.
1 Communication impaired by a hodgepodge of inappropriate and misused cohesive structures
0 Incomprehensible collection of disconnected ideas and words, or only one sentence.

Marking this weekend required only four hours to mark 25 laboratories including writing comments on the laboratories. There are still students not completing laboratories, but I am down to only two who have turned in none of the three labs to date. One conclusion I've reached is that I do not think I could handle too many more than the 32 student target cap in the course.

The workload for students is fairly ferocious - a paper a week. The conclusion, however, is typically only a paragraph, not a multi-paragraph essay. I have not run a survey on whether access to computers is a problem for students. One student had a USB key failure, he was given an extension to turn in lab three.

At present the laboratories are carrying 44% of the points in the course. Quizzed and test one hold 51% of the points. The rest is in attendance and homework. With all the work required in the lab, I'd like to see it up near 50%, and the addition of three points in the rubric for organization should help push the laboratory up towards 50%.

Intense calculations
Working together as a team

Laboratory issues I am still wrestling with include whether a lab team can submit a joint laboratory. One pair did this for laboratory three. While science is often done by teams, I do not know how to ensure that everyone on a team pulls their own mass, so to speak. I can see teams where the team will always turn to one student to get the laboratory written up, and that feels problematic. For now I am continuing to require individually done lab reports.

I am also looking at whether the full blown laboratory paper a week pace is simply too heavy for the students. Thus far I am inclined to continue to push the students. One colleague noted that they only do three per term in the full format such as I am using. I see that I am getting more labs in the desired format as of lab three.

I've explained to a couple students that one of the skills they should be gaining is the ability to rapidly assemble a complex paper. This is a skill that transcends physical science and will do them stead in many other courses and fields.

I continue to provide "starter" templates on line for the students to use in laying out their laboratories.

Looking ahead to spring

As I noted in an earlier email, the labs change from the 8:00 Thursday section to the 11:00 Thursday section. And further changes are made post-lab. In some sense every laboratory has been a failure in that each has needed revision. At the same time no lab is a scientific failure - the systems we are observing are doing just what they are supposed to do scientifically.

I've already heavily redesigned laboratory four with a new version. I have also been in touch with Dave Trapp who designed a science module lab similar to my lab 04 and Joe Arsenault at the University of Maine who also designed a marble momentum laboratory for their GK-12 Sensors! modules. Both have provided me with valuable insight into the complexities of the system in laboratory four. Decreasing external torque should improve laboratory four - WD-40 sounds like a promising way to reduce these torques at this point.

I would note that air tracks are typically used in the physics laboratory to demonstrate conservation of momentum, and we could theoretically buy one or - if I were clever enough - build one. The catch for me is that this removes the laboratory from the realm of the totally familiar. Students know marbles and think they understand marbles. In part one every student because perplexed and even mesmerized by the simple yet puzzling behavior of the marbles. How do they know what to do? This kind of deep perplexity cannot be generated by fancy technical equipment as the students will think that it is a unique behavior to the air track apparatus. The students would not be as puzzled - the whole thing would be an unfamiliar mystery, so the further mystery of conservation of momentum would be lost to them.

In addition, the lab is well within the reach of a local school system. Part one only requires marbles and rulers. Part two and three do require a timing device, but a teacher might get lucky and either own or have a student who has a watch with a chronograph. It was simple systems that Galileo and Brachistone played with, it was simple systems that Newton thought about. Hence the apocryphal story of the apple.


Sorry for the length of this monologue. I realize, however, that I am making major changes in a course. These changes will eventually lead to an outline that looks very different from the present 108 factoid outline. Very different. Given that I am varying from the present outline, I feel compelled to keep the division, chain of academic command, and members of curriculum committee aware of what I am doing and why.

Will students cover all the content of the outline or textbook? No, not even close. Yet ten years post-class what of the 108 factoids will any student ever remember or use? My driving goal is for students to engage in science as a process, content serves that goal. There is content, but content with comprehension. Or so I hope. I want students to engage in inquiry throughout their lives, to not accept things without questioning. Call it critical thinking, call it inquiry based learning, but these are the rather ephemeral goals of the class. Decades of factoid-content driven science have led to citizenries that accept any memorized fact system as equivalent - hence the acceptance of intelligent design as science rather than faith. The problem is not with intelligent design - it is science that has been taught as faith. Kinetic energy is 0.5mv². Memorize that, accept it on faith alone, that is the basic design of physical science at present. Laboratories are "glued on" and often not even integral to the "lecture" component. An afterthought designed to convince the authors of the text that the principles in the text are true. One does not sell hundred dollar plus texts that have only 16 concepts in them.

I have a lot of work ahead of me in understanding what is being done in other community colleges and colleges in physical science. I remain wedded to the text in part for fear of getting too far from "what everyone else is doing." So for now the course retains a lecture component and hews to the text in these lectures.

I would ask that those who get a chance to travel and visit other schools please ask about physical science in those schools. I would love to get a hold of syllabi, outlines, and anecdotes on how courses elsewhere are evolving, if they are evolving. Sometimes what is actually happening the classroom is not discoverable from on line resources.

Notes on physical science curriculum tranformation efforts elsewhere

For those who have the time and inclination, there is a nice introduction to the less is more approach advocated by the American Association of the Advancement of Science at: http://www.project2061.org/publications/articles/articles/da.htm

TERC has also long been involved in transforming science education from reading about science to doing science.

SDSU is also experimenting with their physical science curriculum. I cannot glean details from the web site, but the course appears to use a packet of activities to guide the course. Fred Goldberg's stated design intent gives me hope that I have not wandered completely off the curricular track, "There will be very little formal lecturing in this course. Indeed, all class sessions will take place in the lab. The basic aim of the PSET format is to allow you to take charge of your own learning, with the instructor as a guide. During class you will spend most of your time performing experiments, working occasionally with computers, and discussing ideas with your classmates."

Queen's University in Canada also embarked two years ago on a push towards deeper learning with the recognition that too much content can encourage surface learning. There are many issues that they are wrestling with from impact on traditional lectures to faculty workload.

California is requiring elementary school teachers to have had a full year of physical science. Cal Poly is redesigning their courses to be more constructivist in their approach to learning, another facet of deeper learning.

I had wanted students to construct their own hypotheses in each laboratory, but this has proven difficult. The students have such a meager background in science, and apparently none in hypothesizing, that this is proving problematic. I have not given up, but lab redesigns include hypotheses where before none were suggested. The students are just too much of a blank slate, missing too many years of science. What little they've had is the factoid variety. At some level I do have to cover something in the world of physical science, I cannot really start tabula rasa and hope that the students can rediscover the whole edifice of science in a single term.

Again, I share this to keep faculty abreast of what I am doing in this general education core course. This is also part of a monologue on developments in science curricula that are paralleled in mathematics and other fields. In many fields there is a drive towards constructivist, deeper learnings, and narrower content coverage. I also know that at some distant future date, the outline for the physical science course will engender many questions. I hope that by sharing what I am doing now and what is influencing the design of the course, other faculty will understand better what I am doing. I also want faculty to know that this is new ground for a community college curriculum, and even I have my concerns as I push forward. I am reassured by other similar efforts elsewhere that I have not fallen off some edge.