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Problem Solving without the Problems. Training for Scientific Thinking in Conceptual Classes. Bradley “Peanut” McCoy Azusa Pacific University. SCAAPT Spring 2010 Meeting April 24, 2010. Ask The Right Question. Textbook Question: The suspended load of a stream _______________.
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Problem Solving without the Problems Training for Scientific Thinking in Conceptual Classes Bradley “Peanut” McCoy Azusa Pacific University SCAAPT Spring 2010 Meeting April 24, 2010
Ask The Right Question • Textbook Question: The suspended load of a stream _______________. • is deposited before the bedload. • is highly soluble substances. • moves along the bottom • usually consists of fine particles • This Question Requires: • Remembering definition of suspended load • Nearly identical words as used in textbook • My class goals: • Understand relationships between concepts • Apply concepts to new situations
Ask The Right Question Stream exits mountains • My Question: • The picture shows a region near the western side of Death Valley. A stream flows down from the mountains. At the point marked in the picture, the stream emerges from a steep canyon in the Panamint Mountains and flows out onto the flatter valley floor. The land directly downhill from the mouth of the canyon is likely made up of • (a) sediment deposited by the stream. • (b) bedrock exposed by the stream’s downcutting. • (c) the same material as the mountains, which has not undergone any erosion or deposition. • (d) large boulders that eroded from the mountains. • This Question Requires: • Remembering definition of terms • Translation to words not used by book • Recognition of a general process • Application to a real world situation
How Physicists Solve Problems 5 Step Problem Solving Method 1. Focus the Problem Visualize Find keywords Identify known quantities Ask the question 2. Describe the Physics Qualitative description Choose principle to use Divide into subproblems 3. Plan the Solution Choose general equations Translate to defined variables Is there enough information? 4. Execute the Plan Do the algebra 5. Check the Solution Check trends and limits Plug in numbers Check units Does answer make sense? Did we answer the question? Competent Problem Solver, Heller, McGraw-Hill (2006)
Conceptual Problem Solving 5 Step Problem Solving Method 1. Focus the Problem Visualize Find keywords Identify known quantities Ask the question 2. Describe the Physics Qualitative description Choose principle to use Divide into subproblems 3. Plan the Solution Choose general equations Translate to defined variables Is there enough information? Choose cause-effect statement 4. Execute the Plan Do the algebra Build cause-effect chains 5. Check the Solution Check trends and limits Plug in numbers Check units Does answer make sense? Did we answer the question?
Cause-Effect Statements: Conceptual Equations • Example cause-effect statements • Short sentences containing “causes” • Link two concepts • Analogous to equations • Algebra works because “Equals” allows substitution • “Causes” allows sequential chain building Steeper land causes faster flowing rivers. A river slowing down causes deposition of sediment. Net force equals mass time acceleration. Flatter land causes slower flow causes deposition of sediment.
How To Implement • Class design recommendations: • In-class training on problem solving process • Meta-homework – practice on problem solving techniques • Emphasize cause-effect statement in summaries or reviews • Peer instruction • Include cause-effect statements on homework • Require problem solving steps on tests Peer Instruction: A User’s Manual, E. Mazur, Prentice Hall (1997) E. Redish and D. Hammer, Am. J. Phys. 77, 629 (2009)
Preliminary Results • Quantitative evidence (small sample) • Test averages • Before cause-effect statements 68.0% (98 students) • With cause-effect statements 75.5% (27 students) • EBAPS epistemological gains (data being collected) • Anecdotal evidence • Student explanations change from “You said so” to using cause- effect statements • Student morale improved • Better concept retention • Better student awareness of what they know or don’t know www2.physics.umd.edu/~elby/EBAPS/idea.htm
“The successful user of mathematics is practically an inventor of new ways of obtaining answers in given situations. Even if the ways are well known, it is usually much easier for him to invent his own way – a new way or an old way – than it is to try to find it by looking it up.” -Richard Feynman Thank you