Visualizing Time in Education: Evaluation of the Triangular Model
ISBN 978-85-88783-11-9
Authors
1Ooms, K.; 2de Maeyer, P.; 3Van de Weghe, N.
1GHENT UNIVERSITY Email: kristien.ooms@ugent.be
2GHENT UNIVERSITY Email: philippe.demaeyer@ugent.be
3GHENT UNIVERSITY Email: nico.vandeweghe@ugent.be
Abstract
Time is a persistent link throughout our lives; everybody gets confronted with it. Not only in their spare time, but also during lectures and while rehearsing courses, students cannot escape a vast amount of temporal information. A clear visual presentation of time benefits students as it strengthens digesting the information. Temporal information is typically visualised using the linear model (LM) in which time intervals are depicted on a 1D axis with numbers or dates. A time interval I with starting point I- = 20 and end point I+ = 75 will be represented by a 1D horizontal line between these two points (along the X-axis). The second dimension (along the Y-axis) can be employed to order the time intervals depicted as such by lines, for example, based on their starting point or duration. Although this still is the most widely used representation mode to date, it comes with a number of limitations, especially when one needs to analyse a large set of time intervals. Typical problems linked to this linear model are: (1) There is no standard to visualise multiple time intervals. The second dimension can be used to order them visually, but this cannot be considered as a full dimension: the distance between the different time intervals in the second dimension has no meaning. (3) An automatic visualization of time intervals is difficult since there is no absolute location of the1D line segments in the 2D space. (2) Since the distance between multiple time intervals is not related to any metric, zooming operations (increasing and decreasing the level of detail in an interactive manner) are not very interesting on these visualisations. (4) The visualisation gets overloaded quickly because time intervals are depicted as lines. This is not a problem when visualising a limited amount of intervals, but for larger datasets the resulting image becomes cluttered. Therefore, the issues mentioned above can introduce problems in education. A less-known model, the Triangular Model (TM), is not confronted with these issues and might thus serve as an interesting alternative. In this model, time intervals are depicted by points (0D) in a 2D space. The construction is based on lines drawn through the start and endpoint of the time interval at 45° and 135° respectively (relative to the horizontal X-axis). The intersection point of these two construction lines defines the interval point (e.g. I1). Consequently, this intersection (and the interval point) will be located higher on the Y-axis in 2D space when the duration of the interval is longer. In contrast to LM, the distance between time intervals along the Y-axis corresponds to an actual measure: the length of the interval. Furthermore, the position of the interval point along the horizontal axis is determined by the interval’s start and endpoint. Previous research has indicated that TM can be understood and used fairly easily by non-expert users. What is more, the (expert and novice) participants’ search behaviour on the TM was more efficient to the LM. An interactive (web-based) visualisation of time intervals in students’ course material could be a significant aid for students to structure the course’s contents and to notice links between the contents across different courses. The goal of this research is thus to implement and evaluate an interactive visualisation of the TM in education. The course ‘Historical Cartography’ is selected in this pilot-project as its contents contain a lot of time intervals at different levels. At the end of the semester, the students’ performance on this course and their opinion on the usability of the TM will be evaluated. If the outcomes are positive, this pilot-project will be extended to potentially all courses with a time component in the Faculty of Sciences, which would result in a unique integration of their contents, with time as a guide.
Keywords
Education; Time Visualization; Triangular Model