Exploring physical science systems using scientific methodologies

proposed outline for SC 130 Physical Science includes the following three course level student learning outcomes:
  1. Explore physical science systems using scientific methodologies
  2. Generate mathematical models for physical science systems and use appropriate mathematical techniques and concepts to obtain quantitative solutions to problems in physical science.
  3. Demonstrate basic communication skills by working in groups on laboratory experiments and by writing up the result of experiments, including thoughtful discussion and interpretation of data, in a formal format using spreadsheet and word processing software.

The second learning outcome serves, in part, the general education program learning outcome, "3.2 Present and interpret numeric information in graphic forms." Student performance against general education program learning outcome 3.2 was reported on in Numeric information in graphic forms skills pre-post assessment.

The third learning outcome serves, in part, the general education program learning outcome, "1.1 Write a clear, well-organized paper using documentation and quantitative tools when appropriate." Student performance on 1.1 was reported on in Lack of writing improvement in physical science.

The first learning outcome requires that the students be able to explore physical science systems using scientific methodologies. For SC 130 Physical Science this exploration would be framed by the theme of mathematical models that underlie physical science systems. This, in turn, serves the general education program learning outcome, "3.5 Perform experiments that use scientific methods as part of the inquiry process."

The inadequacy of the science curriculum in the elementary and secondary schools does not well prepare students to explore physical science systems in a wholly unguided and unstructured manner. Laboratory fourteen is designed to provide minimal structure and guidance. Laboratory fourteen provides only a system, a suggested starting approach, and an explanation of the equipment being used and the variables being investigated. The system was chosen to be new and unfamiliar to the students.

Emmy Rose, Pamela, and Correy take measurements

In the past the students were provided equipment to investigate whether a mathematical relationship exists between the launch velocity of a flying disk (or ring) and the flight distance. Rain and swampy conditions on the lawn led to a decision to give them a non-linear system - length versus period for a pendulum.

The students were to make a non-statistical determination as to whether a relationship  exists and, if so, whether the relationship is linear. If the relationship appeared to be linear, the students should have known to proceed on to an analysis that included the slope and intercept. A complete laboratory would include a discussion of the sources of error. Although the system is known to be non-linear, at the lengths in use and the errors in measurement made by the teams the system appears to be linear except for the inferred data point at 0 cm length, 0 seconds period.

Eleven of fifteen students completed laboratory report fourteen summer 2014. Note that while students may work in pairs or small groups during the laboratory, each is required to complete their own laboratory report. Four students did not complete the laboratory report. The students had only two school days to complete the report, for some this was insufficient. Earlier laboratories provided one week.



The eleven students who completed the reports all generated data tables with labelled header rows, xy scattergraphs with labelled axes, made a determination of what they thought might be the nature of the mathematical relationship, and generated a trend line equation either linear or non-linear using spreadsheet software.

Seven students decided that the system appeared to be linear, with all seven proceeding to quote the slope and intercept values after determining the system was linear. Note that the order is important: the linear slope and intercept have no meaning unless the system is linear, thus a determination of linearity should precede quoting the slope and intercept. The remaining four students decided the system was non-linear and chose to use quadratic (polynomial) regressions which fit reasonably well to the data. Bear in mind that the students have not been exposed to the theory that drives the pendulum system, nor are they familiar with square root relationships. Over the short lengths investigated a polynomial trend line appears to fit very closely to the data

Two students who chose a non-linear relationship discussed the nature of the relationship in a careful manner than indicated that they understood the system to be non-linear. No report showed evidence that the students had tried to look up the actual relationship. This reflects, in part, the intentional avoidance of refering to using on line resources in the class. In my experience, if the students are told to research a question on line, the students then tend to copy and paste what they find. I prefer to see their own thinking and writing, so I intentionally do not mention using on line resources during the course. This is potentially problematic as the students do not develop a habit of cross-checking results against known on line values or resources. The upside is that I see almost no plagiarism of on line resources in physical science - a common problem I have had in a course such as ethnobotany.

Whether a student should be able to work through a system from raw data to a complete and appropriate mathematical analysis after a single 16 week science with laboratory course is a matter for discussion. At some level all eleven engaged with the data and drew a meaningful, if not fully complete, conclusion.

Laboratory fourteen was designed to provide assessment data pertinent to the first learning outcome on the proposed outline. The other assessments provide information relevant to the other course learning outcomes. By moving to outlines with only course learning outcomes, more insightful assessment is possible. Assessment moves from being static numbers of student success rates, which provide no information on how to improve those numbers, to real insights into what the students know, what the students can do, and what the students value.

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