# The Usefulness of Video Learning Analytics in Small Scale E-Learning Scenarios
## 3 Methods and Materials
### Data Analysis
In that case, the whole session was discarded. Less than 0.1% of sessions presented anomalous data. The raw collected data, as presented in Table 2, may not be easy to interpret for untrained stakeholders. Thus, in order to present the data to teachers and other stakeholders in the involved courses, the collected data was processed and converted into a variety of visualizations. We did not use the visualizations seen in the literature, as they did not seem appropriate for our volume of data and the objective of intervention in the learning process at the individual or small group level, more suitable in small scale scenarios. Firstly, a visualization (see Figure 2) was developed to present single playback sessions. This was used to show teachers how there were a significant number of students that did not watch the videos from beginning to end without skipping forwards or backwards or pausing. For each video, the five playback sessions with the most recorded events were shown to the teacher, accompanied by a summary of skipping and pausing data. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Page Accessed** & **Video** & **Timestamp** & **Action** & **Parameters** \\ \hline Tue, 10 March 2019 11:27:44 GMT & 05585\_01 & 11:27:44 GMT & page loaded & \\  & 05585\_01 & 11:27:49 GMT & play & 0 \\  & 05585\_01 & 11:27:50 GMT & seek & 77.867 \\  & 05585\_01 & 11:27:51 GMT & seek & 196.011 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: An example of the collected data for a typical session. Parameters are described in the text. Presenting data for single playbacks is challenging because, as video is a time-based medium, there are two different time variables involved: \"video time\" and \"session time\". By \"video time\" we refer to the position in the video a student is currently watching. By \"session time\" we refer to the elapsed time since the session began. As most video playback interfaces use the horizontal axis to represent \"video time\", the horizontal axis in the graph has been chosen to represent \"video time\", while the vertical axis is used for session time. Thus, video playback appears in the graph as diagonal segments (typically with slope 1, although, if a student watches video at an accelerated rate slopes are bigger, and lower if a student watches at a slower speed). Pauses appear as vertical segments, with the length of the pause corresponding to the length of the segment. Finally, skipping backwards or forwards appears in the graph as horizontal segments. Secondly, in order to present the skipping forwards and backwards behaviour, data are visualized using scatter plots (see Figure 3 for an example). In this case, both axes represent \"video time\". Every time a student skips in a video, she skips from a starting point to an ending point. The horizontal axis has been chosen for starting points, while the vertical axis has been chosen for ending points. Thus, every point in the plot represents a jump. Points below the diagonal represent backwards jumps, while those above the diagonal represent forwards jumps. Points close to the diagonal represent short jumps, while those further away from it represent longer jumps. It was a common occurrence in the data that a student skipped many times in a very short amount of time. This was generally interpreted as the student looking for a certain point in the video. It is not desirable to show this in the graph as many jumps instead of one, so an arbitrary modifiable parameter, \(t\), has been introduced (in the examples used in this work, it has been set to one second). If two jumps appear in the data for the same session, less than \(t\) seconds apart, then they are considered a single jump, from the starting point of the first jump to the ending point of the second jump. This is applied iteratively to simplify skipping behaviour. Figure 2: Single playback visualization for a typical session. The video is 810 s long (13\({}^{\prime}\)30\({}^{\prime\prime}\)), and the playback session lasts 1013 s (16\({}^{\prime}\)53\({}^{\prime\prime}\)).