evidential bases & e/m (promoting evidence-based reasoning) dr. frank jenkins (retired) centre...
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Evidential Bases & e/m(promoting evidence-based reasoning)
Dr. Frank Jenkins (retired)Centre for Mathematics Science
and Technology Education (CMASTE)Secondary Education, U of A
Edmonton Physics Teachers, 2011-10-12
“Evidence”: the most important word in science
Often teachers do not find time (or lack the resources) to present evidence for their claims to knowledge to students.
The pedagogic purpose of this presentation is to increase teacher awareness, understanding and action on a variety of ways to present evidence in the classroom (with no excuses).
CMASTE Evidential Base ProjectE.g., e/m ratio of the electron
1. thought experiment
2. demonstration3. wet lab (actual)4. dry lab (lab
exercise)5. simulation/
animation (Word)
6. video lab (YouTube)
7. photo lab
8. photo analysis
9. computer
probes/sensors10. field trip (UofA e/m)
11. primary literature12. remote access
(computer control of remote e/m equipment)
Use this page to access e/m examples.
1. A thought experiment to describe and explain the experiment and even predict the results for the experiment includes talk, hand-waving, equations, and diagrams used often in classrooms due to efficiency and low cost
I A
Figure 1: e/m tube(applying a magnetic field to bend an electron beam in a circle)
Figure 2: Alignment of Helmholtz Coils(balancing Earth and Helmholtz magnetic fields)
B
E HB
1. A thought experiment
Advantages
A thought exp. may: save time and money be completely oral require hand waving require a diagram require equations may accompany a
static demonstration be used pre/post lab
Disadvantages
A thought exp. may not: suit visual learners suit tactile learners suit slower learners improve lab/tech skills improve inquiry skills realistically portray the
nature of science be used to test concepts
2. A demonstration
Advantages
A demonstration may: save time save money Improve accuracy improve reliability improve attention improve learning be good PD for the teacher demonstrate KSAs allow for student
participation
Disadvantages
A demonstration may not:(relative to a student lab) suit the learning style of some
learners allow for student participation allow the learning of
manipulative skills promote deep understanding promote evidence-based
reasoning promote scientific attitudes
3. A “wet” (student) lab
Advantages
A wet lab may: promote scientific
attitudes allow for assessing
technological skills reinforce learning increase interest increase knowledge of
scientific inquiry
DisadvantagesA wet lab may not: save time save money promote order create a safe
environment suit teachers who are
without the required laboratory KSAs
4. A “dry” lab—lab exercise--providing parts of a lab report
Advantages
A lab exercise may: save time & money emphasize the need for
evidence promote Analysis or any
other parts of a laboratory report
be used in all assessment tools (e.g., quizzes & tests)
improve the writing of lab reports
Disadvantages
A dry lab may not: promote technological skill
development promote scientific attitudes promote scientific inquiry promote confidence in
laboratory work reveal the interaction of
science & technology replace laboratory work
Hints: (1) Use simulations to provide “evidence” of creating the lab exercises. (2) No test should be without a lab exercise.
5. A simulation/animation computer based
Advantages
A simulation may: save time & money introduce or reinforce real
laboratory work—pre/post help visual learners help learning at a distance be repeated as many
times as required (7/24) be used as an assessment
tool (from the screen) be good PD for teachers
Disadvantages
A simulation may not: promote laboratory skill
development promote scientific attitudes promote scientific inquiry promote confidence in
laboratory work reveal the interaction of
science & technology be accessible to some schools,
classrooms & learners
6. A video lab computer based or not
Advantages
A video-lab may: save time & money introduce or reinforce real
laboratory work—pre/post help visual learners help learning at a distance be repeated as many
times as required be created by students or
teachers with new-tech be good PD for teachers
Disadvantages
A video-lab may not: promote laboratory skill
development promote scientific attitudes promote scientific inquiry not include a quantitative
component (just qualitative?) promote confidence in
laboratory work be accessible to some schools,
classrooms & learners
7. A photo lab computer- or paper-based
Advantages
A photo-lab may: save time & money introduce or reinforce real
laboratory work—pre/post help visual learners be repeated as many
times as required (7/24) be used in assessments be created by students or
teachers with new-tech be good PD for teachers
Disadvantages
A photo-lab may not: promote laboratory skill
development promote scientific attitudes promote scientific inquiry not include a quantitative
component (just qualitative?) imitate laboratory work provide the required action(s) be accessible to some schools,
classrooms & learners
8. A video- or photo-lab analysis computer-based analysis
Advantages
A photo analysis may: save time & money introduce or reinforce real
laboratory work—pre/post help visual learners be repeated as many times
as required (7/24) be used in assessments include quantitative analysis interest those with cameras
Disadvantages
A video analysis may not: promote laboratory skill
development promote scientific attitudes promote scientific inquiry imitate laboratory work show the full complexity of real
laboratory work be accessible to some schools,
classrooms & learners without the required digital technology
10. A computer probe lab computer-based (hand held?)
Advantages
A probe/sensor lab may: introduce or reinforce real
laboratory work—pre/post help tactile & visual learners introduce higher technology
to the laboratory promote field work (where
evidence is retrieved later) include quantitative analysis be good PD for teachers
Disadvantages
A probe/sensor lab may not: save time and money promote basic laboratory skills be accessible without field-trip
work (e.g., to rivers & ponds) be accessible to some schools,
classrooms & learners without the required money/technology
be accessible to individual students (e.g., demos only)
be robust enough for student use
11. A primary-literature lab using academic research reports
Advantages
A primary-lit lab may: save money (and time?) reflect real-world science introduce or reinforce
laboratory work—pre/post promote science history promote science biography promote science language promote scientific attitudes include quantitative analysis be good PD for teachers
Disadvantages
A primary-lit lab may not: promote basic laboratory skills promote real scientific inquiry interest some students be accessible to students with
low reading abilities be accessible to students
unless the primary literature (PL) is adapted (APL)
be accessible unless it is classical (new reports require licensed access to journals)
12. A remote-access (Internet) lab using equipment remotely (with video)
Advantages
A remote-access lab may: save money and time introduce or reinforce
laboratory work—pre/post access high-tech equipment help tactile/visual learners help learning at a distance be repeated as many times
as required (7/24) be good PD for teachers
Disadvantages
A remote lab may not: promote laboratory skill
development promote scientific attitudes promote scientific inquiry promote confidence in
laboratory work be accessible to some schools,
classrooms & learners be provided by universities that
are short of cash/technicians
Evidence-Based Reasoning
My experience is that there are many students, teachers and in the public who do not understand the importance of evidence-based reasoning; e.g.,
psychic fairs, pseudoscience, astrology climate-change deniers lack of understanding of what research
is about, even in their field of work
Evidential-Bases: Advantages
removes excuses for not including laboratory work (& evidence) in science courses
promotes “evidence” as an important word and concept central to science
promotes evidence-based reasoning promotes laboratory work/inquiry promotes scientific attitudes promotes scientific language promotes the nature of science
Q: Where does evidence get applied?A: Everywhere!
In the classroom: curriculum instruction teacher language in worksheets lab exercises student language media samples, …
In textbooks: text (e.g., language)
visuals (e.g., photos)
laboratory work
In tests/assessments lab exercises simulations photos or video
Evidential Bases for CTU CycleLab Type
Linear Momentum
Angular Momentum
Light Spin & Orbital AM
Create(I)
computer simulation
use falsifying evidence
use falsifying evidence
Test(HI/HD)
verify in the demonstration
verify by video or photo analysis
verify with evidence from primary lit
Use(D)
quantitative analysis in lab exercise (exam)
in computer probe analysis
qualitative analysis in the laboratory
Test(HI/HD)
falsify in the laboratory
falsify via a thought experiment
falsify by remote access
Evidential Base
Create(inductively)
Test (verify) Use(deductively)
Test (falsify)
thought exp. demonstration “wet” lab “dry” lab simulation
video lab
photo lab video analysis comp. probes
field trip
primary lit.
remote access
A lab program for a major concept
Your Turn: Present the evidence on [any concept].
1. thought experiment
2. demonstration3. dry lab (lab
exercise)4. wet lab (actual)5. simulation/
animation
6. video analysis7. video evidence8. photo evidence9. computer probes10. field trip11. primary literature12. remote access
Evidence-based language to be used in the classroom and laboratory
“Based upon Lab 6.2, we know that ….”
“According to the research conducted by ….”
“Peer reviewed research in Nature suggests that ....”
“This was only an initial (unreplicated) study but ....”
“Our interpretation of the evidence is that ….”
“Careful control of all known variables suggests that ….”
“This is only a correlational study and not a cause and effect study so ....”
“If [procedure] and [evidence], then [analysis].”
“Anecdotal evidence suggests that ….”
“The certainty communicated is three significant digits.”
“We use evidence to create and test a concept before we go on to use it.”
Evidence-based science education
Acknowledgements CMASTE Dr. Wytze Brouwer Dr. Isaac-Yakoub Isaac Dr. Brian Martin and
his students at Kings Univ. College
Hans van Kessel my students
Contact me: Dr. Frank Jenkins [email protected]
Websites www.CMASTE.ca (general)
– Evidential Bases (specific)
www.KCVS.ca (see e/m) www.CRYSTALAlberta.ca