Julie Greenberg January 20, 2005
description
Transcript of Julie Greenberg January 20, 2005
Using Interactive Web Applications to Help Teach Math
and Science Concepts:An Example from Signal
Processing
Julie Greenberg
January 20, 2005
Background
Biomedical Signal and Image Processing (HST582J/6.555J/16.456J) 25-35 students once/year (Spring term) Graduate level subject
mostly seniors and first-year grad students Diverse backgrounds
HST, EECS, MechE, NucE, Aero/Astro 90-minute lecture twice weekly 4-hour software lab once per week
Initial Problem
Motivated by my frustration in teaching Fourier spectral analysis Observed that students couldn’t apply lecture
material in lab Experience shared by my colleagues Many students seemed to be overwhelmed by
interaction of variables Difficulty preparing examples for lecture
Initial solution
Developed a simulation/interactive demonstration to permit hands-on exploration of key variables in spectral analysis: Select signal sources (sum of cosines, ECG,
speech) Select parameters (window length, window shape,
DFT length) Options to save and compare parameter sets http://web.mit.edu/6.555/www/matweb/demo.html
Simulation: Input Screen
Simulation: Output Screen
New Problem/Concerns
We have the simulation. What do we do next? What are advantages/disadvantages of this type of
educational technology? How do we make effective use of this educational
technology in the context of the course?
Used alone, the simulation would likely have led to “fiddling” without much learning.
Overview of approach
Defined learning objectives and key concepts Great value to having these stated explicitly
Implemented Legacy cycle Reused/modified existing
educational activities Added new elements
Small group discussions Interactive tutorial to guide
students as they use the
simulation to develop
understanding of key concepts
Identified Learning Objectives
Student can analyze and interpret frequency content of biomedical signals
After completing this module, students should be able to: analyze the effects of multiple variables on a
frequency-domain representation select parameters to perform frequency analysis of
a signal, given desired specifications interpret a given frequency-domain representation,
given the parameters used make inferences as to the parameter used,
given a frequency-domain representation
Identified Key Concepts
Major Concept: Fourier spectral analysis
Supporting concepts: factors affecting amplitude resolution factors affecting frequency resolution effect of changing window length effect of changing window shape effect of changing DFT length effect of changing multiple parameters
simultaneously
Legacy Cycle: 1 of 4
Initial Challenge Design an electrocardiogram (ECG) monitor to
detect life-threatening ventricular arrhythmias 90-minute guest lecture on cardiac function 15 minute introduction in lab
Legacy Cycle: 2 of 4
Generate Ideas Students brainstorm in groups of two 30-40 minutes in lab
Multiple Perspectives Class reconvenes in lab Each group presents their ideas Other students and instructor comment Moderated discussion follows 30-40 minutes in lab
Legacy Cycle: 3 of 4
Research and Revise Interactive tutorial on Web
Learning objectives and key concepts guided our generation of tutorial content
Series of questions that explore key concepts with immediate feedback
Guidance for using simulation General text summaries of key concepts Glossary, tables, figures Optional hints and tips
Spectral analysis lecture – chalk and simulation
Legacy Cycle: 4 of 4
Test your Mettle students work in pairs to solve the ventricular
arrhythmia challenge (entire four hour lab session during following week)
homework problem
Go Public individual lab reports quiz
Results
Students liked it Survey data indicates strong positive reaction
Student learning improved Study shows that students using the module
demonstrated better understanding of key concepts than students not using module (JEE April 2003)
Instructor and TAs liked it Extremely rewarding
Take Home Messages
Provide framework (e.g. web-based tutorial) to support students in making effective use of educational technologies
Identify learning objectives and key concepts Strategic planning for teaching
Use HPL/Legacy cycle to deliver on learning objectives. Provides overall structure so that elements (e.g.
tutorial and simulation) are used in a pedagogically-informed context
Credits
Julie Greenberg, project leader Dinh-Yen Tran, simulation software Jeffrey Steinheider, simulation software Natalie Smith, tutorial implementation Tomas Lozano-Perez, tutorial software Leonardo Cedolin, teaching assistant Minnan Xu, teaching assistant Sean Brophy, learning sciences consultant Mark D’Avila, learning sciences consultant Lori Breslow, learning sciences consultant John Newman, assessment and evaluation
consultant