Mass, Measurement, Materials, and Mathematical Modeling: The Nuts and Bolts of Extrapolation Ted Chambers – Prince George’s Community College

Mass, Measurement, Materials, and Mathematical Modeling:

The Nuts and Bolts of Extrapolation

Ted Chambers – Prince George’s Community CollegeScott Sinex - Prince George’s Community College

Josh Halpern – Howard University

Presented at ACS MARM, College Park, MD on 21 May 2011

First Semester Chemistry Activity• 24 Students - Worked in Groups of 4

• Group Interaction to Discover Underlying Concepts

Experience Gained• Graphing

• Data Analysis Using Excel

• Mathematical Modeling Using Excel

• Group Collaboration Using Google Docs

Pre-built into spreadsheet

Technique Used• Mass a Bolt with One through Five Nuts On It

• Determine Mathematical Model for the Data

• Extrapolate To “Zero Nuts” To Determine Bolt’s Mass

• Enter Data In Google Docs

• Group Collaboration - Discussion Based on Google Docs Data

• Explore Effect of Scatter in Data

• Explore Pitfalls of Extrapolation

Local Evaluation of Data Variation and

Extrapolation Pitfalls

Data Analysis

Examine Data Collaboratively Using

Google Docs

Examine Data Locally

Enter Data and Results In Google Docs

Excel Plot Of Bolt Mass With Various Number Of Nuts

Data With Linear Regression Line

Sharing Results Using Google Docs

• 6 Groups, Each Representing a Different Institution

• Enter Data In Google Docs Using a Form

• Examine Data in Real-time Using Google Docs Spreadsheet

• Collaborative Discussion Between Groups

• Use of Current Technology In a Collaborative Setting

Online Google Docs Data Entry Form

Link to form on spreadsheet

Google Docs Spreadsheet – Collaborative Discussion

Effect of Variation in Data Using Excel

Performed Locally – Not in Google Docs

• Random Variation in Mass

• Effect On Slope

• Effect on Goodness of Fit

• Density of materials (not discussed today)

Data With Random Variation Added

Possible PitfallExtrapolating Past Known Data Range

Students Provided Anonymous Feedback

Results of Ranking Questions

out of 5Instructions Clear and Unambiguous 4.33

Activity Was Informative About Extrapolation 4.38

Size of Work Groups Appropriate 4.54

Activity Rated as a Learning Experience 4.13

Activity Overall Rating 4.20

Students CommentsPositive Feedback

• Using Google Docs to Compare and Discuss Results• Using Excel for Modeling and Data Analysis• Working In Groups• Bringing Innovation to First Semester Chemistry Course• Using The Same Format to Look at Different Group’s Data

Suggestions and Negative Feedback• Activity Too Long (took 2.5 hours)• More Computers in Lab With Internet Connectivity

General Lab Activity Results• Good Discussion Within Groups

• Good Discussion Between Groups Using Google Docs

• Exploring Differences In Results

• Raised Awareness of Possible Pitfalls of Extrapolation

• Good Data Agreement Between Groups

Questions?

This work is supported by the Howard/Hopkins/PGCC Partnership for Research

and Education in Materials (PREM), funded by NSF Grant No. DMR-0611595

http://academic.pgcc.edu/~ssinex/excelets/matsci_excelets.htm