Thursday, December 22, 2011
Judging a Science Fair – Lincoln Park
On December 20 I was a judge at the science fair for Lincoln Park High School. I was recruited by my daughter who attends this school. There was no conflict of interest because she was not participating. Since I was a judge for the Central Region Chicago Public Schools Science Fair in January 2011, I wanted to compare the two experiences. This is an article about my impressions, not a comprehensive review. My college senior son also came with me and was a judge. Since I see many graduates of Chicago Public Schools in the City Colleges, I wanted to meet some of these high school students.
The whole judging process was very organized. Each project/exhibit was judged by four judges. Each project had judging sheets of four different colors assigned to each judging cycle. The sheets had a rubric containing four areas (written report, oral presentation, quality of display, and review of literature) to judge the project. The points totaled 100. The scale was: 80-100 Outstanding; 50-79 Excellent; 0-50 Honorable Mention. There was no option for “not acceptable.” Only five projects could go on to the next level.
Last January I was not impressed by the level of science experiments and reporting by the student scientists. This time the reports were much better written and some of the projects showed some creativity. However, one of the teacher sponsors, she said too many students did experiments with lima beans. I only judged one project that used lima beans, but there were about 60 others.
Many of the projects presented information that I suspected was inaccurate, but I was unable to check facts while at the school. One project was supposed to be measuring the amount of saturated fat in several kinds of oils. The student used a reactive test agent and I found no evidence in the paper that this agent would really measure what she claimed it would. Another used iodine as an indicator. The review of literature did not really show the reader how the experimenter knows this is a valid test.
One experiment that showed creativity wanted to measure the effect of temperature on musical pitch of glasses. The student wanted to make tuned glasses. She filled glasses with water at three temperatures and measured the pitch. She was careful to control the amount of water and used the same kinds of glasses. One of her pictures was a glass harp instrument. There were two problems with her methodology. Temperature would be hard to maintain during a practice or performance. She could tune the glasses before the concert, but the temperature would stabilize to room temperature. The second methodological problem is how she measured the pitch. She is a trained musician. She played a pitch pipe and used her ear to assign notes from the scale. I asked her why she didn’t use a digital tuner. She said that she didn’t have one. I went online and found tuners that would do her job for about $7-15. That does not sound like much to pay for precision measuring devices.
While a skilled musician can tell when a pitch is correct, the brain has a threshold of perception of differences. That threshold, called just-noticeable difference (JND), depends on the tone’s frequency. The A above middle C is 440 hz and is the reference for the other notes. The problem with labeling results with just the notes of a scale is that the C on a piano is not the same pitch as the C on a transposing instrument such as a Bb clarinet.
Another student wanted to measure amount of saturated fat in three oils – canola, olive, and peanut. The student added an indicator to 20 ml of oil and counted the number of drops. The more drops, he reasoned, the more saturated fat. I have no idea if this is a valid test. The review of literature did not convince me either way.
Lactose intolerance is common enough to encourage the food industry to produce lactose free products. Lactose is the sugar found in cow’s milk. People avoiding dairy products for health of kosher reasons (separating meat and milk) will not want a product that contains lactose. Even products labeled as “non-dairy” according to the Department of Agriculture’s rule can contain lactose and be according to Jewish law considered “dairy.” One student wanted to measure the amount of lactose in fluid milk, reconstituted dry milk and soy milk. I can’t give the entire methodology because I didn’t take notes, but the hypothesis is flawed. The experiment was performed to remove the lactose and it was measured. The results showed that soy milk “contained” lactose. I questioned the student and he stood by the results. At home I looked on the soy milk label. It said, “Lactose free” and it was kosher and parve (no dairy or meat ingredients). Since I believe the label over a high school experiment, the experiment should have been redesigned. The student should have read the labels on products to determine better candidates for testing.
Most of the experiments suffered from too few samples. Three or five samples are not enough for a statistically significant result. Some were closer to an observational report than experimental results. It is hard for a high school student to choose and design a project that will show originality and creativity. Most questions will take more time than students have allotted to the project. Students should spend a significant amount of time reading and exploring ides before they even choose an experiment. They should read published experiments to learn how scientists report their results. Many of the experiments and papers could have been improved with a consultation with a teacher or other knowledgeable adult. Science fair is an opportunity for students to explore the world, develop research skills and hone their critical thinking skills. We need to encourage creative minds.