Create-Test-Use and Evidential Bases

Frank Jenkins, U of A, IHPST 2007 1

Create-Test-Use and Evidential Bases

IHPST Conference 2007University of Calgary

Frank Jenkins, U of A, IHPST 2007 2

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 3

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 4

Natures of Science Umbrella

Problem Solving

Processes

Skills

N ature of Science

I H-I H-D D

s

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Natures of ScienceLab Type

Nature of Science

Philosopherof Science

Date ofIntro.

Create inductive(specgen)

Francis Bacon

1600s

Test hypothetico-deductive/-inductive

Karl Popper

1930s+

Use deductive(genspec)

Aristotle 300s BC

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Lab Report: ProcessesPurpose Create (I) Test (H-I) Test (H-D) Use (D)

Problem general general specific specific

Hypothesis X mental hypothesis

mental hypothesis

X

Prediction X X specific X

Analysis empirical hypothesis

empirical hypothesis

empirical particular

empirical particular

Eval. 1 evidence evidence evidence evidence

Eval. 2 X hypothesis predictionhypothesis

X

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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.

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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 10

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 11

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 12

Create-Test-Use in the Nelson Chemistry 20-30 Alberta TextbookCTU(T) or (T)CTU cycles1. defining a cmpd.2. intramolecular bonding3. gas laws4. solubility rules5. defining acids/bases6. stoichiometric law7. 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

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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.

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Evidential Bases1. thought

experiment2. demonstration3. dry lab (lab

exercise)4. wet lab5. field trip

6. video lab7. video analysis8. simulation/

animation9. computer

probes/sensors10. remote access

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Evidential Bases—1Evidential Base Description1. Laboratory(wet lab)

evidence gathered in the laboratory by the students

2. Demonstration(wet lab)

evidence gathered in the laboratory by the instructor

3. Thought experiment

design & evidence presented verbally by the teacher

4. Lab exercise(dry lab)

evidence gathered for the students and put into a lab format

5. Field trip evidence gathered in the field

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Evidential Bases—using computersEvidential Base Description

6. Computer (or not) video

evidence provided in a video format (to be analyzed by students)

7. Computer analysis of video

evidence is analyzed by computer software

8. Computer simulation

evidence provided in a computer simulation/animation format

9. Computer probes evidence gathered by computer probes (to be analyzed by students)

10. Remote access by computer

evidence gathered in the laboratory by Internet access

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Evidential Bases for CTU CycleLab Type

ArrheniusConcept

Bronsted-Lowry A-B

Lewis A-BConcept

Create(I)

computer animation

use falsifying evidence

use falsifying evidence

Test(HI/HD)

verify in the demonstration

verify in the laboratory

verify in a demonstration

Use(D)

qualitative analysis in lab exercise

in computer simulation

qualitative analysis in the laboratory

Test(HI/HD)

falsify in the laboratory

falsify in a demonstration

falsify in a video lab (more eg’s)

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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.

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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

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Ultimate Curricular Goals for Evidence-Based Science Education 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

Frank Jenkins, U of A, IHPST 2007 22

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, [email protected]