• Open Access

Categorization of first-year university students’ interpretations of numerical linear distance-time graphs

Thomas Wemyss and Paul van Kampen
Phys. Rev. ST Phys. Educ. Res. 9, 010107 – Published 15 February 2013

Abstract

We have investigated the various approaches taken by first-year university students (n550) when asked to determine the direction of motion, the constancy of speed, and a numerical value of the speed of an object at a point on a numerical linear distance-time graph. We investigated the prevalence of various well-known general graphing difficulties, such as graph-as-picture errors and slope-height confusion. We established that two-thirds of our students could determine the direction of motion with respect to a reference point, just under 80% could determine that the speed is constant, and just under 20% of our students could correctly determine the value of the speed; in the latter case, about half of the students divided the two coordinates. Three stable categories of correctly explaining the constancy of speed emerged from the data. We found that the reason given for determining that the speed of the object was constant did not correlate with successfully determining a value for the speed. We have established that technical difficulties such as determining the slope of any linear graph did not explain the poor performance. By comparing the answers to similar questions on water level versus time graphs, we were able to establish that context dependence and incorrect prior learning are likely to play a role. Post-test data are used to confirm the validity of the categorization and support the conclusion that being able to determine the slope of a y,x graph and having a correct qualitative understanding of a distance-time graph is not sufficient to correctly determine a value for the speed.

  • Figure
  • Figure
  • Figure
  • Figure
  • Figure
  • Received 15 May 2012

DOI:https://doi.org/10.1103/PhysRevSTPER.9.010107

This article is available under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Authors & Affiliations

Thomas Wemyss and Paul van Kampen*

  • Centre for the Advancement of Science and Mathematics Teaching and Learning & School of Physical Sciences, Dublin City University, Glasnevin, Dublin 9, Ireland

  • *Paul.van.Kampen@dcu.ie

Article Text

Click to Expand

References

Click to Expand
Issue

Vol. 9, Iss. 1 — January - June 2013

Reuse & Permissions

Authorization Required


×
×

Images

×

Sign up to receive regular email alerts from Physical Review Physics Education Research

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 3.0 License. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

×

Log In

Cancel
×

Search


Article Lookup

Paste a citation or DOI

Enter a citation
×