2.1

Stylus

A Wacom metal tablet and stylus were used to control the mouse for drawing on the computer screen. The tablet cost approximately $180. It connected by USB to the computer and acted as a duplicate touchpad. Although it takes at least one extended test session to get accustomed to writing naturally on the metal surface, it eventually becomes automatic and is much more nuanced than finger strokes on a typical laptop touchpad.

Touchscreen displays with styluses (e.g. the Microsoft Surface) continue to improve and are viable alternatives to the metal tablet. Compared to such touchscreens, the metal tablet does have some advantages. For example, the Wacom metal tablet can operate in a mode where it is completely insensitive to contact with the user’s hand. Using a stylus directly on a touchscreen typically produces one or more inadvertent strokes per recording session due to the user’s hand (when the pen tip is too far away from the screen to override it). Another minor advantage is that, when writing on a metal tablet, one’s hand does not obscure any of the existing writing on the actual screen.

2.2

Drawing program

The canvas for the drawings in these videos was the work area of the free drawing program SmoothDraw (www.smoothdraw.com). This simple program provides several different colors and pen thicknesses. Importantly, it enables several color choices to be mapped to function keys. The user’s non-writing hand can therefore change the pen color without the pen having to leave the canvas, which cuts down on wasted time.

2.3

Recording program

Screencasts were recorded using the free version of the program ActivePresenter (https://atomisystems.com/activepresenter/free-edition). There are many programs available that can record screens with audio input. ActivePresenter has a few key properties that were not found combined in any other free program. First, it enabled recording from a subregion of the screen. This meant that the unimportant control areas surrounding the SmoothDraw canvas did not have to appear in the recording; one could record solely from the actual drawing area, for a cleaner effect. The subregion also meant that it was easy to place other needed windows (e.g. for computer simulations) outside the recording area and drag them in when needed, rather than having to “unhide” them from the background.

A second important feature of ActivePresenter is that it provides a rich editing environment for the recording. Most simply and almost most crucially, it makes it easy to delete sections of the video. There were three separate ways in which the deletion process improved the final video over the real-time original:

The free version of ActivePresenter did place a watermark logo in the upper right-hand corner of the videos. The area blocked was not a big problem.

2.4

Dissemination

Videos were exported from ActivePresenter to .MP4 format and uploaded to YouTube. On both computers and smartphones, YouTube viewers currently enable playback at higher speeds such as 1.5X and 2X. This creates a win-win situation: if the instructor speaks slowly and carefully to avoid mistakes, the sped-up audio isn’t too fast for the students’ comprehension, so they can watch (and re-watch) the video in less time.

Links to the videos were embedded in online quizzes that were disseminated to the students via the course’s Learning Management Software (LMS) system. Each quiz revealed the link and required that the students answer one to three short questions related to the material in the video. The students knew that taking the quizzes affected their participation grade.

3.1

Use of classroom time

With the mathematical derivations shifted to online preparation, class would now start with a challenge question inspired by one of the assigned videos. Students would work at their desks for a few minutes, vote on the correct answer (if appropriate), and hold a class discussion of the correct answer. This enabled the instructor to assess how well the class was utilizing the relevant material from the video. Just-in-time mini-lecturing would follow as needed, often with a screenshot of the video shown on the projector to remind students of the video content. When the screenshot was shown, students would frequently come up with new questions about the video.

The remainder of most class periods was spent working on parts of the current problem set, with chances for just-in-time teaching as needed. This was the explicit contract explained on the first day: that the flipped classroom would not increase their time commitment to the course, because some of the lecture time “saved” by watching a video would be “given back” in class to make progress on the homework.

3.2

Student compliance and feedback

Typically, more than 90% of students completed the online quiz for any given video. That does not prove that the students watched the video itself; they could have answered the questions without watching, since participation scores were not graded for correctness. No direct metrics were gathered from YouTube on the number of unique users who watched the videos.

Student feedback on the videos was strongly positive. At mid-semester, students completed a three-question survey: “What should this class START doing? STOP doing? KEEP doing?” The majority of the responses to “KEEP doing” focused on the videos. Students said that the videos were helpful and that they valued the way the video content was linked to in-class problems and discussions. They also mentioned that they liked having the videos around so they could review them prior to the two midterms and the final exam.

3.3

Pitfalls

Converting derivations to online tutorials creates some problems. Obviously there is the nontrivial time commitment associated with creating the videos; in this instructor’s hands, it took at least 2 hours just to record and edit a 15-minute final video, not including the preparation before the recording. This work is of course offset by the fact that the video can be reused in subsequent years. There are, however, other challenges that are more systemic.