Mass, Measurement, Materials, and Mathematical Modeling: The Nuts and Bolts of Extrapolation

1. Mass, Measurement, Materials, and Mathematical Modeling: The Nuts and Bolts of Extrapolation Ted Chambers – Prince George’s Community College Scott Sinex - Prince George’s Community College Josh Halpern – Howard University Presented at ACS MARM, College Park, MD on 21 May 2011

2. 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

3. 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

4. Data Analysis Examine Data Locally Enter Data and Results In Google Docs Examine Data Collaboratively Using Google Docs Local Evaluation of Data Variation and Extrapolation Pitfalls

5. Excel Plot Of Bolt Mass With Various Number Of Nuts

6. Data With Linear Regression Line

7. 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

8. Online Google Docs Data Entry Form Link to form on spreadsheet

9. Google Docs Spreadsheet – Collaborative Discussion

10. 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)

11. Data With Random Variation Added

12. Possible Pitfall Extrapolating Past Known Data Range

13. Students Provided Anonymous Feedback Results of Ranking Questions out of 5 Instructions 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

14. Students Comments • Positive 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

15. 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

16. Questions? http://academic.pgcc.edu/~ssinex/excelets/matsci_excelets.htm This work is supported by the Howard/Hopkins/PGCC Partnership for Research and Education in Materials (PREM), funded by NSF Grant No. DMR-0611595