USING EXCEL TO INDIVIDUALISE BASIC MATHEMATICS ASSIGNMENTS

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USING EXCEL TO INDIVIDUALISE BASIC MATHEMATICS
ASSIGNMENTS

• DEE Conference, Cambridge, Sept 2007
• Mike Rosser
• Department of Economics, Finance and Accountancy
• Coventry University
• Coventry CV1 5FB UK
• m.rosser_at_coventry.ac.uk

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Overview of Method

• Individualised questions are created for each
  student based on their ID number
• All students get same assessment sheet, but
  letters represent digits in ID number
• An easily readable answer grid for manual
  marking is generated via Excel.
• Note This presentation just summarises method.
  See paper for specific examples and formulae.

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Rationale

• Students need to practise examples to develop
  their mathematical skills.
• Weaker students are often reluctant to put in the
  effort required unless their work is assessed.
• Collusion is likely if students are set the same
  questions for coursework.

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Other Advantages

• Manual marking is relatively quick but still
  gives students feedback on specific errors.
• Can ask students to interpret results.
• Can set more time consuming questions than in
  time constrained or on-line tests
• Can include problems requiring students to
  construct their own spreadsheets

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Background

• Following Coventry 2006 degree revision
• Mathematical Techniques taught to all Yr 1
  Economics students in same module
• Most do not have A-level Maths, some have weak
  GSCE Maths, so a very mixed ability group
• Accountancy students also attend term 1, which
  focuses on financial mathematics

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Teaching Philosophy

• Objective to get all students practising worked
  numerical examples.
• Used in lectures and formative practice
  questions, as well as the summatively assessed
  individualised questions
• Approach based on Mike Rosser (2003) Basic
  Mathematics for Economists 2nd Edition, Routledge

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Converting student ID numbers

• Use Excel to convert ID number to digits
• Specify letters B to H in questions instead of
  numbers (Col A used for ID). For example
• If question specifies TR 5EFq 1Gq2
• For student ID 1234567 TR 545q 16q2
• (Note the mix of numbers with letters.)

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Dealing with Student 007

• To ensure acceptable values for students
  answers, some actual numbers may be used with the
  letters representing ID digits.
• For example, for student ID 0000007, if digits
  DE represent the interest rate in an investment
  problem, a rate of 0 may lead their
  calculations into a dead end
• If interest rate is specified as 5.DE then this
  student would use 5.00 in his problem.

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From Digits to Question Parameters

• Excel can convert ID numbers to individual digits
  by dividing by 10, 100, etc., and rounding down.
  ( One off task)
• Parameters can then be created by multiplying by
  10, 100, etc. For example, for
• An amount invested 8FGH
• 8,000 100 x 5 10 x 6 7 8,567

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Full Workings Spreadsheet Page

• Before producing Answer Grid, best to create
  Full Workings page, with columns showing
• Actual numbers created for each student ID
• Intermediate steps in complex answers
• For students who get answers wrong, this will
  enable tutor to check
• If students started off with the wrong number
• At what stage answer started to go wrong.

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Calculating Answers

• From the tutors perspective, perhaps the most
  difficult task is devising an Excel a formula
  that will provide the mathematical solution to
  each question
• For most teachers of mathematics for economists
  this will not be too difficult a mathematical
  challenge
• Can devise formulae based on standard algebraic
  solutions to mathematical economics problems.

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Example Full Workings

• For demand function P 2CD - E.5Q
  and the supply function P 2F 3.G Q find
  equilibrium price P and quantity Q.
• When full list of ID numbers is pasted into
  column A the formulae for the numbers each
  student uses and their answers can then be copied
  down the worksheet page

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Answer Grid

• Need to eliminate intermediate stages to get
  answers to fit on one page
• Make second worksheet page and delete unwanted
  columns off Full Workings to get

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Answer Grid Coventry Assignment 1 Example

• First few columns shown (with fictitious IDs)
• Includes spreadsheet investment problems.
• Illustrates range of numeric answers

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Marking Students Work

• Manual marking of method relatively quick if
  answers are correct
• If answer incorrect the tutor can use Full
  Workings to help check if error not obvious
• Allows feedback on where went wrong
• Can over-ride and type in if student inputs a
  wrong digit ( and adjust mark appropriately)

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Evidence - Coventry Results

• June pass rate up from 69 to 80
• Student survey satisfaction with assessment
  methods 81
• Several students made basic errors
• Eg plus/negative signs mixed up
• Manual marking allowed feedback on where students
  need to improve / take more care

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Conclusions

• First Coventry trial of Excel generated maths for
  economists individualised questions has shown
  some success in pass rates.
• Lessons have been learned from the experience in
  setting questions, constructing and using the
  Answer Grid
• Method will be used again and refined.
• Feedback from others using it are welcomed.