KEY ISSUES IN SCIENCE LEARNING Confronting “Intuitive” Theories conceptual change vs. new information Developing Scientific Reasoning hypothesis testing vs. hypothesis creation Building Expertise science facts vs. scientific thinking

CONFRONTING STUDENTS’ MISCONCEPTIONS Problem: Movement of a ball exiting a curved metal tube Your task is to draw a line corresponding to the path the ball would take once it left the tube

CONFRONTING STUDENTS’ MISCONCEPTIONS Problem: Movement of a ball exiting a curved metal tube Two Possible Answers Curved Path Straight Path College Student Answers 51% 47%

CONFRONTING STUDENTS’ MISCONCEPTIONS Problem: Moving object over a cliff Consider a typical cartoon character who runs over a cliff and falls into the valley below. With a pencil, you should draw the path that the falling body will follow. Different subject responses: A, B, C, and D

CONFRONTING STUDENTS’ MISCONCEPTIONS Problem: Moving object over a cliff Answers from High School and College Students Path A5% It will go straight for a distance and then go straight down (roadrunner path) Path B 35% It will go straight for a distance and then gradually arc down (impetus theory) Path C 28% It will arc downward, maintaining constant forward speed and increasing downward speed (correct) Path D 32% It will fall straight down as soon as it leaves the edge of the cliff

TWO PHYSICS: “IMPETUS” THEORY VS NEWTON’S LAWS Impetus Theory: Organized around the belief that “impetus” is acquired when an object is et in motion. The impetus keeps the object in motion until it dissipates. The acquired impetus keeps the object moving in the direction that it was going when it acquired the impetus. Newton’s Laws of Motion: Objects do not require any force to continue moving at a constant speed (or to remain at rest). Instead, an external force is required to alter the velocity of a moving (or resting) body. Direction of movement is a function of the original direction of the moving object and the direction of applied force (see rocket problem - slide 8).

CONFRONTING STUDENTS’ MISCONCEPTIONS Problem: Tossing a Coin A coin is tossed from Point A straight up into the air and caught at Point E. In the space to the left of the diagram, draw arrows corresponding to the forces acting on the coin at Point B. Draw longer arrows for larger forces. AE C.. BD

CONFRONTING STUDENTS’ MISCONCEPTIONS Problem: Rocket Moving in Space A rocket is moving sideways from Point A to Point B. The engine is turned on for 2 seconds at Point B, as the rocket travels to Point C. Draw the path of the rocket.

CONFRONTING STUDENTS’ MISCONCEPTIONS: TRAINING IN NEWTON’S MECHANICS Study: College students’ performance on the coin and rocket problems before and after a course on mechanics % Correct Coin Problem Rocket Problem Before Course 12% 11% After Course 28% 23% Note: Performance after course is still very weak!!!!

IMPLICATIONS FOR INSTRUCTION CONFRONTING MISCONCEPTIONS SELF EXPLANATION IDEATIONAL CONFRONTATION Ask Students to Explain Science Text as They Read Reconcile Predications With Actual Results PREDICT - OBSERVE - EXPLAIN Predict What Will Happen Observe What Happens Explain Why Observations Conflict with Predictions