With the question I chose, "Turning the Dial", I interviewed three adults to see if a common physical science and real life lesson had stuck with them from high school until now. The scenario, found in Physical Science Assessment Probes from the National Science Teachers Association, was that a student puts a pot of water on the stove top to boil and turns the dial to high. When the dial is on high the water boils vigorously with large bubbles and when the dial is turned to low the water boils gently with smaller bubbles(pg. 47). I asked each of my interviewees the question, "Is the temperature of the water (A)greater when the dial is on high, (B)greater when the dial is on low, or (C)the same at both settings?"
Here were their answers:
1. My friend, Maureen, a sophomore education major here at King's, chose (A) because "the higher you turn it up, the bigger the flame, so the hotter it gets."
2. My mom, Kelly, an avid cook in my house, chose (C). When I asked her why she chose (C) she said "well boiling is boiling, right?"
3. My boyfriend, Hayden, a sophomore science education major, chose (C) because "water boils at 212 degrees no matter what"
After each interviewee gave me his or her answer, I questioned each further. I asked "Why do you think that?", "Have you experienced this firsthand?", and "Are you not entirely sure?". Maureen said she was between answers (A) and (C), but (A) seemed more logical to her. Kelly said she has experienced boiling temperature before firsthand, but she has never physically tested the temperature with a thermometer, so she was going more on her gut feeling that the temperatures would have to be the same. Hayden said he was definite in his answer because he remembered this fact from science classes and he has taught temperature lessons in his pre-student teaching.
After questioning, I informed each person of the final correct answer. Kelly and Hayden were correct in saying that the temperature has to be the same at both settings. This is because "temperature is a measure of the average kinetic energy of the molecules in a system. Heat energy increases the kinetic energy of the molecules in the water"(NSTA-pg. 48) Once a liquid reaches its boiling point, it does not increase. The boiling point of water is 212 degrees Fahrenheit (100 degrees Celsius) as Hayden had stated in his response.
This graph shows the temperature of water increasing until reaching its boiling point.
Each interviewee, whether right or wrong in his or her response, had a response that seemed to be valid and true to each in his or her mind. The logic behind the correct answer may lead to an incorrect response if the student does not have much background knowledge of the topic or if their knowledge is not associated with a real problem/question. Although this topic is one that can be viewed very often in the home, adults have misconceptions about the definite answer. Bridging the gap between school subject knowledge and real world examples could be an issue related to students' misconceptions. Problem Based Learning allows students to construct their own knowledge around the topic at hand, which may help to bridge this learning gap. 'Students should be given problems...that require them to decide what evidence is relevant and to offer their own interpretations of what the evidence means." (Gallagher, pg. 11) I feel that using Problem Based Learning engages students and makes meaning between subject material and life outside of school.
National Science Teachers Association. Physical Science Assessment Probes. Pages 47-52.
Boiling Water. Retrieved March 26, 2013 from http://www.sophisticatededge.com/what-is-the-boiling-point-of-water.html
Water Boiling Point Graph. Retrieved March 26, 2013 from http://www.mrkscience.com/planbook/Physical%20Science/October09.html
Gallagher, Shelaugh. Problem Based Learning[PowerPoint slides]. Retrieved from online website: http://www.rfwp.com/pages/wp-content/uploads/2011/06/engaged-educated-keynote.pdf
