Interactive (Lecture) Demonstrations Suggestions for Preparing and Performing Thought-Provoking Demonstrations

Interactive Demonstrations -1 An interactive demonstration generally consists of a teacher manipulating a scientific apparatus and then… – asking probing questions about what will happen (prediction) –or how something might have happened (explanation). Cognitive conflict serves as an excellent mechanism to engage students.

Interactive Demonstrations - 2 The teacher is in charge of conducting the demonstration, developing and asking probing questions, eliciting responses, soliciting further explanations, getting student commitments to various explanations, and helping students reach conclusions on the basis of evidence.

Interactive Demonstrations - 3 The teacher will elicit preconceptions, and then confront and resolve any that are identified. The teacher models appropriate scientific procedures at the most fundamental level, thereby helping students learn implicitly about inquiry processes.

The 8-Step ILD Process - A* 1. The instructor describes the demonstration and - if appropriate - does it for the class without measurements displayed. 2. The students are asked to record their individual predictions on a Prediction Sheet, which will be collected, and which can be identified by each student's name written at the top. (The students are assured that these predictions will not be graded, although some course credit is usually awarded for attendance and participation at these ILD sessions.) 3. The students engage in small group discussions with their one or two nearest neighbors. * David Sokoloff & Ronald Thornton

The 8-Step ILD Process - B 4. The instructor elicits common student predictions from the whole class. 5. The students record their final predictions on the Prediction Sheet. 6. The instructor carries out the demonstration with results clearly displayed. 7. A few students describe the results and discuss them in the context of the demonstration. Students may fill out a Results Sheet, identical to the Prediction Sheet, which they may take with them for further study. 8. Students (or the instructor) discuss analogous physical situation(s) with different “surface” features. (That is, different physical situation(s) based on the same concept(s).)

Pointers - Preparation Make adequate preparation: –everything in working order –everything in place –rehearsed

Pointers - Visibility Ensure visibility for each student: –large equipment –background consideration –color added to liquids –adequate illumination –elevation to appropriate level –do not hid parts with your body

Pointers - Simplicity Keep it as simple as possible while still making the point: –avoid unnecessary complexity (adjustments) –avoid overly specialized equipment –use commonplace materials if possible –diagram setup if necessary

Pointers - Safety Exercise safety precautions: –wear safety goggles –use a protective screen –keep students back –keep first aid and other emergency equipment on hand –take full advantage of your facilities (exhaust fan, mirrors, etc.)

Pointers - Performance Perform the demonstration smoothly. –set up apparatus in front of students –have components out of sight but at hand –be precise in your technique –handle the demonstration yourself

Pointers - Requirement As a general rule, students should be expected to make a written record of each demonstration. –done as part of class notes or a lab record book –use a simple and flexible reporting format: What was done? What happened? What do you think about it? Include sketches if helpful

Additional Uses Remember that demonstrations may be done in more than one way, depending upon the purpose of its use. –as an adjunct to lecture or discussion –as a laboratory exercise –as an observation exercise –as an opportunity for student participation (if appropriate)

Important “failings” Some teachers fail to maximize the educational benefits associated with the use of a demonstration: –Be certain to avoid the show-and-tell mentality –Seek student commitments in an effort to elicit preconceptions and produce cognitive conflict when possible