Physics and webCT

Improving introductory physics at Iowa State

– Phys 111, 112, 221 and 222, enrollment 1300/semester Concentrate on Phys 222

– Online assignments– Discussion board– Lecture notes– misc., mygrades, skill profile,….

Craig Ogilvie, Department of Physics and Astronomy

cogilvie@iastate.edu

Phys 111, 112, 221 and 222

Improving courses, ongoing :) – active-learning in lectures, small group discussions– problem-solving emphasis– group project, apply physics-modeling to industrial,

engineering system Use of webCT, online assignments

– reduce grading for TAs» frees time to work with students (see above)» Or reduces number of TAs =>costs

– improve the feedback to students on their work

Online Assignments

Four types of assignments– pre-lecture ‘reading’, simple questions to encourage

text-book usage– pre-labs, questions to prepare for lab-tasks– conceptual assignment

» once per week– quantitative homework

» once per week

Mechanics

Multiple-choice questions written in Respondus Calculated questions, numerical grading engine webCT

– if no graphics or equations, write directly in webCT– otherwise Respondus =>upload to webCT =>convert

Pre-lecture Pre-lab Concept Quantitative

390 200 650 620

1) Question sets, students receive different questions2) Developing mySQL database to store, select questions

ready by end of Spring 04

Typical Quantitative Question

You are designing a circuit that has a very long, essentially infinite, wire which has an upwards current that increases at a rate of di/dt, where di/dt > 0. Also on your circuit, but not connected to the long wire, is a square loop (length of each side is “a” and whose closest edge is a distance d from the wire). The changing current in the long wire will induce an emf in the square loop. This is a common problem in many circuits. What is the induced emf in the square loop, and which direction would the induced current flow?

1) solution requires student to develop ½ page of algebra2) assesses quantitative skill, ability to combine several ideas

Multiple-Choice Answers Available

clockwise counter-clockwise

clockwise

clockwise

clockwise

counter-clockwise

counter-clockwise

counter-clockwise

A

C

B

D

E

H

F

G

1) Not possible to guess answer2) Wrong answers deliberately chosen for common mistakes3) Partial credit awarded

Submission Patterns

More than 90% students submit each assignment 60% of students submit within two hours of deadline

Sample of one assignment (one of the harder ones)

Score drops if assignment started in last hour

Feedback

Full solution– step-by-step instructions on how to set up the

solution Specific advice if student chose one of the wrong

answers– e.g. “It looks like you made a mistake calculating the

flux through the square loop. Did you forget that the B-field decreases with 1/distance from wire?”

Impact of Timeliness of Feedback

Randomly split students into two groups for 1 week– Induction physics, Faraday’s law – group A received immediate feedback on problem set– group B received feedback after due date of problem set

Any difference in learning the physics of this assignment ?– scores on standard magnetism diagnostic

preprepost

g100

“Gain” = fraction of possible improvement

All questions <pre> = (18.30.8)% <post> = (59.71.3)%

g=0.510.02, n ~280 students,

Average Gains vs Timing of Feedback

No strong evidence that students who received immediate feedback learned more than students with delayed feedback

0

0.1

0.2

0.3

0.4

0.5

0.6

ga

in F2000

F2001

Immediatefeedback

Delayedfeedback

preprepost

g100

Gain measured for induction questions

Discussion Board

More than 1000 messages per semester– Information queries– Gripes ( recommend monitoring strangetalk.net ) – Assignment questions (one topic per assignment)

» Student-student replies, TA-student replies, ..» Example of thread next page

Student B i didn't have this question but try q=mc delta t and go from there. Hope that helps.Student A The problem I am running into is that there are two unknowns - what fraction of the ice melts and what fraction of the water freezes, while I only have one equation (if I take all the Qs and equate them to 0). how can I solve for the two unknowns?Student C Think of this question as how much water freezes instead of how much ice melts.

Student A Thank you so much - it was foolish of me to think that the water could freeze and the ice could melt at the same time. Your suggestion was like a light bulb flashing!

Student A My problem is the one that involves 20g of water at 10 degrees C and 300g of Ice at -10 degrees C and trying to find the total change in entropy of the system. I think I need to find the amount of ice that melts and the final temperature. Thanks for any help in advance.

Lecture Notes

pdf, ppt made available before lecture– Active-learning conceptual questions not included

page views of lectures Fall 2003

0

500

1000

1500

1 5 9 13 17 21 25 29 33 37 41

Lecture #

nu

m o

f vi

ews

Lecture attendance still high > 75%

490 students

Gradebook

Assignments, pre-labs etc. Bubble-sheet scores from test-services TAs hand-enter

– Lab-grades, project scores Tremendous value

– Students find our “accounting” errors =>fix them – Track performance

Downside– Not possible to segment by TA

Upside– Uploading of letter grades to registrar :)

Next Steps: Skill Profile

Each question => skill weights for several categories– N/A, low, med., high-skill needed to solve problem

Categories– use of multiple concepts, geometry, algebra ….

Calculate a “skill level” for each student in each category

Problems attempted

level skillweight

weightcorrect

Provide students their updated skill profile each weekMeta-cognitive: “what type of problems do I get wrong?”

Wish/concern list

Rubric data entry– TAs use rubric for lab-grading but enter total score– Better would be a “graphical” interface of rubric

» TA “click” on a rubric-grid for each student Fast data entry

» Splits the scores up into each category, Allows student to monitor improvement

More page tracking– how often non-content pages viewed? e.g. solutions

Need “assignment availability/closing” bug fixed

Conclusions

Redesign of physics courses @ ISU– active engagement during lectures– group projects on realistic modeling– use webCT to free TAs from grading

» better use of TA time» Cost-savings

– on-line assignments» immediate, specific feedback possible

Lectures, discussion board, gradebook – well used

Contact me with any questions, cogilvie@iastate.edu

Backup

TA Survey

Usage (I)

E.g. weekly quantitative problem set, 4-5 questions– Each question ~ ½ page of work– Random sample of 100 students mid-way semester

time left when assignment started

05

1015

2025

1 2 6 12 24 48 72 96 120

hours till deadline

assi

gn

men

ts

Usage (II)

Random sample of 100 students mid-way semester

0

10

20

30

40

11 10 9 8 7 6 5 4 3 2 1 0

Hours left till deadline

Su

nm

itte

d

Time assignment submitted