200 likes | 337 Views
Create-Test-Use and Evidential Bases. IHPST Conference 2007 University of Calgary. Definition of Science. Science is the study of the natural world in an attempt to describe, explain, and predict changes and products.
E N D
Create-Test-Use and Evidential Bases IHPST Conference 2007 University of Calgary Frank Jenkins, U of A, IHPST 2007
Definition of Science • Science is the study of the natural world in an attempt to describe, explain, and predict changes and products. • A goal/purpose of science is to create, test, and use (with confidence) a scientific concept (and then to falsify). Frank Jenkins, U of A, IHPST 2007
Epistemological ChoicesWhen Presenting a Concept • Inductive (creating a concept) • Hypothetico-inductive (testing) • Hypothetico-deductive (testing) • Deductive (using the concept) Frank Jenkins, U of A, IHPST 2007
Natures of Science Umbrella s Frank Jenkins, U of A, IHPST 2007 I H-I H-D D
Natures of Science Frank Jenkins, U of A, IHPST 2007
Lab Report: Processes Frank Jenkins, U of A, IHPST 2007
Creating the Arrhenius Concept of Acids and Bases--inductively • Purpose: To create the Arrhenius concept of acids and bases. • Problem: What kinds of chemicals form acidic and basic solutions; i.e., are acids and bases? • Design: Each of the solutions is tested with litmus paper. Frank Jenkins, U of A, IHPST 2007
Testing the Arrhenius Concept of Acids and Bases—H-I • Purpose: To test the Arrhenius concept of acids and bases. • Problem: What kinds of chemicals form acidic and basic solutions; i.e., are acids and bases? • Hypothesis: Chemicals whose formulas begin with H are acids and end with OH are bases. • Design: Each of the several new solutions is tested with litmus paper. (Note: Say to test, not to verify.) Frank Jenkins, U of A, IHPST 2007
Testing the Arrhenius Concept of Acids and Bases—H-D • Purpose: To test the Arrhenius concept of acids and bases. • Problem: Which of the provided solutions is an acid or a base? • Prediction: According to the Arrhenius concept, the acids are … and the bases are …. • Design: Each of the solutions is tested with litmus paper. Note: embrace falsification (as well as verification). Frank Jenkins, U of A, IHPST 2007
Using the Arrhenius Concept of Acids and Bases • Using any concept in laboratory work usually involves qualitative and quantitative analysis—esp. in chemistry. • The Arrhenius concept of acids and bases is used, for example, in the Analysis during acid-base titrations (which may also use the stoichiometric method) and to test the stoichiometric method. • Most often the Arrhenius concept is used outside the laboratory in regular chemistry problem solving; for example, predict which of the following chemicals is an acid or a base? • Create-test-use works within and between laboratory work and normal pencil and paper work. Frank Jenkins, U of A, IHPST 2007
CTU(T) or (T)CTU cycles defining a cmpd. intramolecular bonding gas laws solubility rules defining acids/bases stoichiometric law redox spontaneity Each major unit in the Nelson Chemistry textbooks start with a falsification (test) lab based upon a previous chemistry concept; e.g., the falsification of the Arrhenius concept the falsification of the assumptions for doing stoichiometric calculations Create-Test-Use in the Nelson Chemistry 20-30 Alberta Textbook Frank Jenkins, U of A, IHPST 2007
Evidential Bases • There are many ways to present evidence in a classroom setting. • There is no excuse for not employing evidence-based reasoning in the classroom. • Schools, teachers and students need choices for how they will gather evidence to create, test and use science concepts. Frank Jenkins, U of A, IHPST 2007
thought experiment demonstration dry lab (lab exercise) wet lab field trip video lab video analysis simulation/ animation computer probes/sensors remote access Evidential Bases Frank Jenkins, U of A, IHPST 2007
Evidential Bases—1 Frank Jenkins, U of A, IHPST 2007
Evidential Bases—using computers Frank Jenkins, U of A, IHPST 2007
Evidential Bases for CTU Cycle Frank Jenkins, U of A, IHPST 2007
Create-Test-Use is: • a chronological (historical) order • a concept that helps to organize a laboratory program • a concept that includes, rather than excludes, alternate views on the natures of science • a concept that helps instructors to see from an external (big picture) view of labs what is missing • a concept that helps instructors to be internally consistent with processes in different kinds of labs • a concept that provides instructors and students with the rules for the knowledge game. Frank Jenkins, U of A, IHPST 2007
Evidential bases has a potential: • to ingrain “evidence” as one of the most important words/concepts in science • to improve the quality of evidence presented to students in the classroom • to increase the quantity of evidence that students gather, analyze and evaluate • to increase the quantity of laboratory work Frank Jenkins, U of A, IHPST 2007
concept of certainty/uncertainty single- and double-blind studies anecdotal evidence reliability (consistency) vs. validity (accuracy) peer-reviewed research grants refereed (peer-reviewed) journals valid experimental designs short- vs long-term studies testing vs. verifying falsification replication of a study research sample size evaluating evidence placebo and Hawthorne effect tolerance of uncertainty statistical significance risk-benefit analysis tolerance for uncertainty problem solving for everyday life Ultimate Curricular Goals for Evidence-Based Science Education Frank Jenkins, U of A, IHPST 2007
Acknowledgements • My education professors for introducing me to the history and philosophy of science • My textbook author colleagues: Hans van Kessel, Dr. Oliver Lantz and Dick Tompkins • My chemistry texts publisher Thomson-Nelson • My high school and university students • My CMASTE and CRYSTAL-Alberta colleagues * Dr. Frank Jenkins, fjenkins@ualberta.net Frank Jenkins, U of A, IHPST 2007