### At a Glance

• STEM
• Physics

#### Instructional Level

• College & CEGEP
• University

• Mechanics

#### Social Plane(s)

• Individual
• Group

• Discussing
• Solving problems

### Technical Details

#### Time

• Single class period (< 90 mins)

#### Instructional Purpose

• Assessment & knowledge refinement

## Overview

In this activity, students will use an Immediate Feedback Assessment Technique (scratch cards) to answer a series of questions in a two-stage exam. This activity should be a formative exam with little impact on their final grade.

The instructor begins by handing out an “exam” with multiple choice questions relating to kinematics, vectors, and coordinate systems. Unlike most exams, the questions are designed to be somewhat ambiguous in order to promote discussion. Individually, students solve and answer each question to the best of their ability. The final question is a particularly nontrivial question in which three solutions are presented to a problem, each using a different implicit coordinate system. Students must determine which coordinate systems are self-consistent in order to determine which solution(s) are correct, and provide a justification for their response.

Students are divided into groups of 3-4 and handed pre-made scratch cards. In these groups, they discuss their solutions to each problem, coming to a consensus. They use a coin to scratch off the corresponding entries on the scratch card, which reveals whether or not it was the correct answer.

If the students reveal incorrect answers, they attempt the question again until they reveal the correct answer. Students can then be graded in part based on the number of revealed answers on the scratch card at the end.

## Instructional Objectives

Students learn to assess and interpret coordinate systems. Students learn that coordinate systems can differ, but must still be internally consistent.

## Contributor's Notes

### Michael Dugdale

John Abbott College, Montreal, QC

Benefits
Challenges
Tips
Benefits

The scratch cards give students immediate feedback, and allow them to take multiple attempts to solve a question. Upon an incorrect answer, they can immediately rethink their solution. There is, however, a penalty for choosing the wrong answer, and the immediate feedback creates a more tension.

The final question is designed to prime on the belief that up is always positive and down is always negative, forcing students to rethink their ideas around coordinate systems. Students have to consider the consistency of the implied coordinate system without it being explicitly explained.

Challenges

The cards are somewhat costly and must be ordered in advance; they can be time-consuming to procure, and the solutions must sometimes be reordered to fit the cards.

Making your own questions and cards is quite time-consuming.

Tips

Students will often ask for clarification on questions, but sometimes the point is to be unclear; try to lead students towards the correct solution rather than giving explicit explanations, as they will have feedback from the IF-AT to confirm whether or not they are correct.

Questions should promote discussion and have some degree of ambiguity, unlike most test questions which require great clarity.

There is usually no need for a formal wrap-up, as students get immediate feedback from the scratch cards, however during this activity you should circulate between groups and answer questions.