Prescriptive Task Analysis and the Teaching and Learning of Physics

J.B. SharmaGainesville State College

Gainesville, GA

Background…Curricular design and pedagogy are always

informed by philosophyThe basis of all philosophy is epistemology …

the axioms or assumptions that underlie the formalism of learning theory

Differing epistemologies lead to different ‘schools of thought’

Effective curricular design and pedagogy involves a constant awareness and questioning of the assumptions that underlie the ‘learning theory’

Opposing Paradigms in Learning Theory/PsychologyObjectivism vs. ConstructivismObjectivism - knowing and learning are

processes for representing and mirroring reality; subject and object are separate

Constructivism - knowing is a process of actively interpreting and constructing individual knowledge representations; subject and object are linked

Analog in PhysicsClassical Mechanics vs. Quantum MechanicsClassical Mechanics separates observer

(subject) and observed phenomena (object); Observor is an ontological construct …

Cogito Ergo Sum (Desacartes)Quantum Mechanics requires an interaction

between observer (subject) and observed phenomena;

Observer is yet undefined and hence Quantum Theory of Measurement is incomplete (Wheeler)

Objectivism..Objectivism has been the dominant

paradigm in Learning Psychology until the late 1950’s

Behaviorism (Skinner) was the dominant Objectivist school of thought

Learning is equated with behavioral outcomes,

Behavioral laws excluded the role of mental operations

Learning based on memorization, drill-and-practice and assessment based on reward or punishment

ConstructivismThe exclusion of the mind from the learning

process by behavioral laws was a primary theoretical cause of the paradigm shift in learning psychology since the early 60’s

Constructivism claims that reality is more in the mind of the knower, that the knower constructs a reality, or at least interprets it, based upon his or her apperceptions.

The emphasis in objectivism is on the object of our knowing, whereas constructivism is concerned with

how we construct knowledge.

Constructivism and Physics EducationConstructivism has been the primary impetus in

physics education reform beginning in the 1990’sThis has informed a shift away from purely lecture to

active engagement of students The ubiquity of personal computing starting in the

early 90’s; A/D cards and real time sensors; data processing and visualization via spreadsheets helped

formalize novel curriculaWorkshop Physics – Laws; Studio Physics – Wilson et

al; Tools for Scientific Thinking – Thornton; Physics by Inquiry – McDermott et al

Constructivism and the Landscape of Introductory PhysicsAt GSC; we have created active learning

curricula and learning spaces that facilitate its implementation

Traditional Lecture and Lab have been integrated and brief lectures have been supplemented by active problem solving in groups, lab activities, student construction of simulations

Students are more engaged and retention has increased

The number of D,W,F’s have decreased

The Novice Learner ‘What do I do Next…’A college physics course is the confluence of

reading, interpretation, writing , mathematical analysis, instrumentation and computation

Effective physics problem solving is predicated on understanding the equivalence of multiple representations – in real space, phase space and in algebraic formulation

This is best learned by solving a lot of problems …

Even with active learning curricula the age old question ‘what do I do next ..’ is ever present

The ‘Sweet Spot’ in the Objectivist vs. Constructivist ContinuumNovice students in algebra and calculus based physics

courses can get held up by minor misconceptions that cause a lot of frustration

I have observed the utility of giving ‘prescriptive task analysis’ for some standard classes of introductory physics problems as an effective ‘crutch’ to help guide their problem solving until they can begin to discern the underlying conceptual patterns clearly

These can be a great help in mastering the basics and allowing subsequent independent learning

A combination of Objectivist elements in a largely Constructivist setting seems to help students master the fundamentals and gain self-confidence to tackle more difficult problems

Examples: Application of Fnet = ma APPLICATIONS of Fnet= ma   For each object involved in the motion :   Line up the +X axis along the acceleration (or tendency to movement)   Draw a Free Body Diagram    Break up all the forces into X and Y components   Set up Fnet= ma along Y axis (to solve for the Normal Reaction force

Rn)    Set up Fnet= ma along the X axis    Centripetal Acceleration ac = v2/r

Kirchoff’s Rules Kirchoff’s Rules Calculation

Determine the number of unique branches/currents in the circuit   Assume a direction of flow of current in each unique branch of the circuit   Mark the polarities of each resistor consistent with your assumption of

direction of flow of current   Set up at least one equation with the point rule   Set up equations using the loop rule   Ensure that you have as many equations as the number of unique currents   Solve the system of N x N equations for the currents   You can calculate the potential difference between any two points on the

circuit by summing up the potential drops and gains along any possible path from one point to the other

Effectiveness of this approach..Is starting to find support in the resaerch literatureIs the basis for ‘Instructional Systems Technology’ Is a function of the judgment of the instructor Can be used to help students master standard

problems and grasp the conceptual basis Can be used to help students summarize the

concepts involved in particular classes of problemsOnce the student has developed self-confidence in

the standard physics problems, it sets up basis for learning advanced concepts

Harnessing the Dialectic Tension for Learning..Using elements of these opposing approaches

to describe learning can be effectively used for incurring effective learning

Task Analysis is a means to the end of greater conceptual understanding and self-confidence in problem solving

There seem to be concepts in which the ‘activation potential’ is greater in which Task Analysis can be more effective – more research is needed to identify these areas

ConclusionsMore Task Analysis modules are being developed

along with a more formal program of assessmentThese ideas have applicability in advanced STEM

courses as wellThe use of ‘Heuristics’ is common in dealing with

complex systems in Engineering, Medicine..To what extent does this resonate with the

experience of other physics instructors ?

Discussion…