# A Scoring Algorithm for the Early Prediction of Academic Risk in STEM Courses
## 4 Overview of the Variables Used in the Analysis
\begin{table}
\begin{tabular}{l c c c c} \hline \hline \multirow{2}{*}{**Week**} & \multicolumn{2}{c}{**Number of Practice Tests**} & \multicolumn{2}{c}{**Maximum of Practice Tests**} \\ \cline{2-5}  & **Mean (Std Dev)** & **Median (Min–Max)** & **Mean (Std Dev)** & **Median (Min–Max)** \\ \hline Week 1 & 0.21 (0.72) & 0 (0–4) & 0.06 (0.20) & 0.00 (0.00–1.00) \\ Week 2 & 0.24 (0.76) & 0 (0–4) & 0.09 (0.25) & 0.00 (0.00–1.00) \\ Week 3 & 0.53 (1.21) & 0 (0–5) & 0.16 (0.33) & 0.00 (0.00–1.00) \\ Week 4 & 2.26 (3.77) & 0 (0–22) & 0.32 (0.41) & 0.00 (0.00–1.00) \\ Week 5 & 0.12 (0.43) & 0 (0–2) & 0.04 (0.16) & 0.00 (0.00–0.86) \\ Week 6 & 0.28 (0.92) & 0 (0–6) & 0.08 (0.24) & 0.00 (0.00–1.00) \\ Week 7 & 0.17 (0.60) & 0 (0–3) & 0.05 (0.18) & 0.00 (0.00–0.92) \\ Week 8 & 0.11 (0.51) & 0 (0–3) & 0.03 (0.15) & 0.00 (0.00–0.86) \\ Week 9 & 0.08 (0.36) & 0 (0–2) & 0.03 (0.14) & 0.00 (0.00–0.86) \\ Week 10 & 1.49 (3.38) & 0 (0–24) & 0.21 (0.30) & 0.00 (0.00–1.00) \\ Week 11 & 0.17 (0.55) & 0 (0–4) & 0.06 (0.20) & 0.00 (0.00–0.86) \\ Week 12 & 0.33 (0.89) & 0 (0–4) & 0.06 (0.19) & 0.00 (0.00–1.00) \\ Week 13 & 0.13 (0.44) & 0 (0–3) & 0.07 (0.24) & 0.00 (0.00–1.00) \\ Week 14 & 0.07 (0.30) & 0 (0–2) & 0.01 (0.08) & 0.00 (0.00–0.57) \\ Week 15 & 1.41 (2.88) & 0 (0–16) & 0.14 (0.28) & 0.00 (0.00–1.00) \\ \hline \hline \end{tabular} Note: The weeks preceding midterm exams are highlighted in light blue.  
\end{table} 
Table 2: Descriptive statistical indicators for the variables _Number_ and _Maximum of practice tests_. Figure 2: The graphical representation of the arithmetic mean and the standard deviation for the variable _Number of learning tests_. the week before the first midterm exam and the lowest in the week before the last midterm exam. Within the Merlin e-courses, students have access to lecture presentations used by the professor. They are encouraged to download these presentations and take notes to support their learning. The course material is structured so that different presentations are used in specific weeks: the first presentation covers weeks 1-3, the second covers weeks 4-6, the third covers weeks 7-9, the fourth covers weeks 10-12, and the fifth covers weeks 13-15. The variable _Presentation_ indicates whether a student has downloaded the presentation for the corresponding week. It takes the value 1 if the presentation was downloaded and 0 otherwise. For example, if a student downloads the first presentation in the second week, the variable _Presentation_ would have the values (0, 1, 1) for the first three weeks. Since _Presentation_ is a dichotomous variable with only two possible values (0 and 1), its distribution across weeks is illustrated in Figure 4. The values of this variable are relatively uniform across the weeks analyzed, suggesting a consistent pattern of engagement with the materials provided. During the 2020/2021 academic year, lectures and exercises were conducted synchronously via remote access, and all exercise sessions were recorded. Based on these recordings, 15 video lessons were created and made available on Merlin, allowing students to access them as supplementary learning material. The variable _Video_ represents the number of times a student accessed video lessons in a given week, including all previously available lessons. The descriptive statistical indicators for the variable _Video_ per week are presented in Table 3. The table indicates that students tend to watch video lessons more frequently in the weeks leading up to midterm exams. Additionally, exceptionally high maximum values are observed, probably due to the way Merlin logs activity, registering an interaction whenever a video is accessed, regardless of whether it is watched in its entirety or merely opened and closed. Figure 4: Graphical representation of the _Presentation_ variable by week. Figure 3: The graphical representation of the arithmetic mean and the standard deviation for the variable _Number of practice tests_. During the semester, students can earn up to 70 assessment points through three midterm exams.