Graphical representations of data improve student understanding of measurement and uncertainty: An eye-tracking study

Developing a better understanding of the measurement process and measurement uncertainty is one of the main goals of university physics laboratory courses. This study investigated the influence of graphical representation of data on student understanding and interpreting of measurement results. A sample of 101 undergraduate students (48 first year students and 53 third and fifth year students) from the Department of Physics, University of Zagreb were tested with a paper-and-pencil test consisting of eight multiple-choice test items about measurement uncertainties. One version of the test items included graphical representations of the measurement data. About half of the students solved that version of the test while the remaining students solved the same test without graphical representations. The results have shown that the students who had the graphical representation of data scored higher than their colleagues without graphical representation. In the second part of the study, measurements of eye movements were carried out on a sample of thirty undergraduate students from the Department of Physics, University of Zagreb while students were solving the same test on a computer screen. The results revealed that students who had the graphical representation of data spent considerably less time viewing the numerical data than the other group of students. These results indicate that graphical representation may be beneficial for data processing and data comparison. Graphical representation helps with visualization of data and therefore reduces the cognitive load on students while performing measurement data analysis, so students should be encouraged to use it.

Figure 1

Distribution of students’ scores on paper-and-pencil test.

Figure 2

Scores on paper-and-pencil test for first-year students and senior-year students divided into groups with graphical representation of data and without it. Average scores for test items 1–7 are shown. The error bars represent 1 SEM (standard error of mean).

Figure 3

Scores of all students on seven test items in study 1 divided into groups with graphical representation of data and without it. The error bars represent 1 SEM.

Figure 4

Example of one participant’s scan path. Centers of circles show position of fixations and lines show saccades. Radius of circle illustrates the duration of the fixation.

Figure 5

Students’ scores in the eye-tracking study for groups with and without graphical representation of data. Average scores for test items 1–7 are shown. Test item 8 did not have graphical representation of data and it was used to control for the differences between groups. The error bars represent 1 SEM.

Figure 6

Scores of all students on seven test items in Study 2 divided into groups with graphical representation of data and without it. The error bars represent 1 SEM.

Figure 7

Heat maps of students who solved the same test item with and without graphical representation of data. Heat maps show how long students looked at different parts of the test item. Red indicates the area of the highest fixation time.

Figure 8

Heat maps of students from two groups (with and without graphical representation of data) for the control test item 8 without graphical representation. Red indicates the area of the highest fixation time.

Figure 9

(a) Average total viewing time at AOI All for groups with and without graphical representation of data. (b) Example of definition of AOIs for one test item. (c) Average total viewing times at defined AOIs for groups with and without graphical representation of data. Average total viewing time is calculated for test items 1–7. The error bars represent 1 SEM.

Figure 10

Students’ scores on paper-and-pencil test and eye-tracking test divided into groups with graphical representation of data and without it. Average scores for test items 1–8 (total test scores) are shown. The error bars represent 1 SEM.

Figure 11

Pie diagrams of distribution of students’ responses for all questions and all participants in study 1. The correct answers are given in bold and denoted by stripes in pie diagrams.

Figure 12

(a) Average total number of fixations (calculated as the sum of number of fixations for items 1a, 2a, 3a, 4a, 5a, 6, and 7) at AOI All for groups with and without graphical representation of data. (b) Example of definition of AOIs for one test item. (c) Average total number of fixations at defined AOIs for groups with and without graphical representation of data. The error bars represent 1 SEM.