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
