Long term stability of learning outcomes in undergraduates after an open-inquiry instruction on thermal science

This paper investigates the efficacy of an open-inquiry approach to achieve a long term stability of physics instruction. This study represents the natural continuation of a research project started four years ago when a sample of thirty engineering undergraduates, having already attended traditional university physics instruction, were involved in a six-week long learning experience of open-inquiry research activities within the highly motivating context of developing a thermodynamically efficient space base on Mars. Four years later, we explore the effectiveness of that learning experience by analyzing the outcomes that the students achieved by answering again the same questionnaire that was administered them both prior to and immediately after those activities. As we did in the first work, students’ answers were classified within three epistemological profiles. Now, a comparison among students’ outcomes during the three phases, namely, preinstruction, postinstruction, and after four years has been carried out. Immediately after the open-inquiry experience, the students obtained significant benefits in terms of the strengthening of their practical and reasoning abilities, by proficiently applying the learned concepts to face and solve real-world problem situations. In this study, the students’ answers do not highlight any significant regress towards their preinstruction profiles. The global robustness of the teaching strategy adopted four years ago is confirmed by a statistically significant comparison with a control group of students who experienced the same curricular instruction except for the open inquiry-based workshop. Nevertheless, some changes have been observed and discussed in the light of the answers the students provided to a short interview regarding their studying or working experiences across the four-year temporal window.

Figure 1

Average similarity index of student answering strategies with pe-type, de-type, or ex-type profiles to address the questionnaire, administered before (red bars), just after instruction (blue bars) and four years after participating the OI-based experience (green bars), in comparison with the results obtained by the control group (purple bars).

Figure 2

Similarity graph for post-4y-instruction (green circles) and control group (purple triangles) data. The squares at the vertexes of an equilateral triangle represent the pe-type, de-type, and ex-type ideal answering profiles. The $x$ and $y$ represent the coordinates in the similarity space. The concentric circumferences mark the distances 0.25, 0.5, 0.75, and 1 from the vertexes.

Figure 3

Similarity graph for pre or post (a) and post or post-4y (b) instruction data. The squares at the vertexes of an equilateral triangle represent the practical or everyday, descriptive and explicative typologies. The $x$ and $y$ represent the coordinates in the similarity space. The concentric circumferences mark the distances 0.25, 0.5, 0.75, and 1 from the vertexes, the colored or numbered symbols represent the students.

Figure 4

Similarity indexes for all the students, each one labeled by an integer index on the abscissa, to the pe-type (a), de-type (b), and ex-type (c). For each student, blue diamonds and green circles connected by an arrow distinguish postinstruction data from those collected four years later.

Figure 5

Similarity graph for preinstruction (left column), postinstruction (central column), and post-4y-instruction (right column) data. The squares at the vertexes of an equilateral triangle represent the practical or everyday, descriptive and explicative typologies. The concentric circumferences mark the distances 0.25, 0.5, 0.75, and 1 from the vertexes. Blue circles represent the students belonging to the research sample, while red diamonds those belonging to the control group.