Common sense is a codification of experience providing meaning to our natural language. Common sense beliefs should be treated with respect by instructors, and regarded as serious alternative hypotheses.
The authors survey concepts about motion by students enrolled in physics courses by a multiple choice diagnostic mechanics test and interviews (see See Whitaker, Robert J.). The multiple choice alternatives are classified as charateristics of either Aristotelian, Impetus, or Newtonian theories.
Nearly every student used some mixture of the theories. Students with quasi-Newtonian beliefs were far more constistent than others. The common sense conceptual systems of the students have much less internal coherence than the Aristotelian an Impetus systems. 61% confused the concepts of position, velocity, and acceleration at least once. During the interviews demonstrations/phenomena appeared to have no effect on their opinions. When a contradiction was recognized or pointed out, they tended at first not to question their own beliefs, but to argue that the observed instance was governed by some other law or priciple. The authors therefor doubt that a demonstration can be effective unless it is performed in a context that elicits and helps students to resolve conflicts between common sense and specific scientific concepts.
Student about the path of projectile: "I have been taught that it goes in a parabola, but never understood why."
Leerlingen denken vaak dat twee objecten dezelfde snelheid hebben, als ze dezelfde positie hebben. Als twee auto's met verschillende snelheden, de een haalt de ander in, vraag: wat zijn de snelheden op dat moment: Gelijk want ze hebben evenveel afgelegd in hetzelfde tijd-interval. Of opm. van leerling t.a.v. bal die een cirkelvormige pijp verlaat: "the ball goes like this (curved path) because it still had some momentum when you were turning it in a circle, and it wants to go in a straight line (...) it goes in a curve until the momentum wears out...then it goes straight." Bij constante kracht dacht 40% van de leerlingen (college students) dat de toename van de snelheid evenredig is met de kracht en de afgelegde weg, 27% dacht dat een kracht niet de snelheid van een object kan blijven verghogen, er is een maximum snelheid afhankelijk van de kracht en de massa van het object.
The authors describe a briefly annotated taxonomy of the most significant common sense concepts, based on two general categories: (1) principles of motion (Newton's law of motion), and (2) influences on motion (laws of force in Newton's mechanics). A few characteristics:
One of the soltutions for these problems is to depend instructional design more on how beliefs are grounded in perception.