Video for Active and Remote Learning.

The outbreak of COVID-19 has caused the canceling of in-person lectures on a massive scale. Rapid movement of education to online platforms will eventually lead to innovations in remote education. At the moment, however, instructors lack guidance. This short article describes approaches for producing video for remote and active learning.

Video: A Versatile Tool in Science Education

When I was 5 years old, Santa brought me a gift that would change my life: a Fisher-Price PXL-2000, a ‘toy’ video camera that could capture 11 minutes of black-and-white video on each side of an audio cassette. At a time when I couldn't even lift the weight of a grown-up’s full-size VHS camcorder, the PXL-2000 was a lightweight marvel of point-and-shoot simplicity. While my filmmaking ambitions rarely went beyond making my stuffed animals act out scenes from Star Wars, I somehow knew that communicating through video would be a defining feature of whatever it was that I would grow up to do.

Fast forward 20 years to graduate school, where I watched Professor Eric Mazur of the physics department at Harvard deliver a seminar on ‘peer instruction’ [1]. This method – which shares indistinct boundaries with similar teaching strategies variously referred to as the ‘flipped classroom’ or ’active learning’ – relies on the students preparing for class by reading a chapter or watching a video and completing an assignment [2]. Class time is then used for problem solving in groups, with the professor behaving more as a ‘coach’ than a ‘performer’. The descriptor ‘flipped’ is thus twofold: problems ordinarily assigned as homework are done in class and peers do much of the teaching.

While there are many ways to incorporate elements of active learning into one’s teaching, it seems to me that it succeeds or fails by the type and quality of the pre-lecture material. In the original conception of peer instruction, the material was envisioned to be a selection from a textbook that the student was directed to ‘read before coming to class’. Some courses, however, are not amenable to prereading. For example, the textbook usually contains much more information than can be reasonably covered in one semester or quarter and animations are impossible to render on a printed page. Moreover, the level of writing in a textbook is often obscure and the usage is sometimes unsympathetic to new learners.

Videos, by contrast, address many of these problems. Humans evolved to understand the spoken word, not the written word [3]. Moreover, with the use of video it is possible to use gestures and facial expressions to communicate a level of subtlety that is impossible with writing alone. When a video is recorded in front of a live audience, expressions of confusion can cause an instructor to change their tack. Even when recording lectures in an empty classroom or office, an experienced instructor has often internalized the type of reaction an ill-formulated explanation is likely to elicit and can explain the concept again in a different way, in real time.

In 2017, I decided to start recording my lectures for use in future courses. I did this for three reasons. (i) I did not feel it was a good use of my time to give the same lectures year after year, semester after semester. Preparing for these lectures often involved rememorizing derivations and other repetitive tasks that left little substrate for imagination. Why not record these lectures for my students (and myself) to learn from in future years? (ii) With the lectures recorded, I could use them as a ‘video textbook’ for my courses. I would thus be free to ‘flip’ all of my classrooms, to transform class time from a traditional lecture – which the students have already seen – into a variety show comprising real-world applications, problem-solving strategies, and group design challenges. (iii) By putting these lectures online and making them freely available, it was possible to reach a vastly greater number of viewers than I could by delivering live, unrecorded lectures. As of this writing, my YouTube channel (‘Darren Lipomi’; Figure 1 ) has over 5000 subscribers with course material that has been viewed roughly 500 000 times. These statistics vastly outnumber my ‘impact’ as a researcher, at least by any citation metric.

Figure 1

A still frame from one of my YouTube videos: ‘Learning from Rejection in Academia’ (https://youtu.be/5zBoZzOgNts).

With the outbreak of COVID-19 in late 2019/early 2020, online course materials have taken on a new importance. Given the lack of time available to adjust, many instructors are understandably struggling to develop an approach. The default strategy emerging appears to be to mimic live lectures, but using an online platform. By contrast, I favor an approach that uses prerecorded lectures of the usual length (perhaps somewhat abbreviated) complemented by separate discussions involving the full class. These sections can take place at a set time, perhaps twice per week. This format preserves the strengths of the video lecture; namely, the ability of the students to watch it on their own schedule and to fast forward, pause, and rewind. It also preserves the type of interaction amenable to the flipped classroom, especially if the platform allows virtual ‘breakout’ rooms for peer-to-peer interaction. Furthermore, prerecorded lectures offer the opportunity to use somewhat higher production values than are available with webcams and onboard laptop microphones.

The Nuts and Bolts of Quality Amateur Video

I favor a minimalist style that emphasizes direct communication of the lecturer with the audience, in contrast to a style that uses extensive design components, transitions, and other technical ‘eye candy’. A principle value of the instructor is the ability to serve as a learning coach and professional role model. While platforms such as Khan Academy are extraordinarily useful for teaching individual topics, their reliance on tablet-drawn diagrams and voice-over narration remove the instructor’s face from the presentation; this distancing is to the detriment of empathy and inspiration that one might derive from interacting with a human instructor in a semester-long course.

A minimalist style does not mean bad production values – quite the opposite. The technology used in the video should be transparent to the viewer. A good video lecture requires not only rehearsal on the part of the instructor, but also decent equipment. Blurry, shaky video and fuzzy, inaudible sound are a constant reminder of the presence of recording equipment (i.e., the opposite of a ‘transparent’ style).

Depending on the budgetary constraints, a stand-alone 4K video camera should be used, along with a high-quality tripod. Sound should always be recorded in duplicate. An amateur creator such as myself inadvertently fails to record usable audio about 10% of the time and thus a backup source is critical. For recording in lecture halls, I recommend wearing two lapel (‘lavalier’) mics, one connected to a stand-alone recorder (e.g., the Zoom H1) and one connected to a wireless transmitter whose receiver is plugged into the camera. For recording in the office, I recommend plugging a lavalier mic with a long cable directly into the input jack of the camcorder. The audio from the microphone embedded in the camcorder is usually of poor quality, although it is sometimes useful on editing as a fiducial mark to sync the higher-quality audio recorded independently. In offices, uncovered concrete, glass, and sheetrock walls produce reverb, which can be suppressed with a few slabs of acoustic foam. To avoid radio frequency (RF) interference, cell phones should also be kept away from audio equipment.

The quality of the image is determined by three things: resolution, stability, and lighting. It is best to record your source material as a 4K master. External hard drives can store many hours of ultrahigh-definition content at low cost. With most amateur camcorders, resolution degrades with lack of stability. If you want someone to follow you around a lecture hall with the camera, a thick-legged tripod with smooth tracking is essential; a gimbal for stabilization is also helpful. With lighting, the goal is to reduce shadows on the performer’s face. That is, light sources should be diffuse and behind the camera. If there is a window in the office, it should also be behind the camera. A good investment would be a pair of square LED arrays to eliminate shadows. It is not vanity: I have found from the analytics of my more amateurish uploads that they have poorer audience retention and fewer views than the ones in which I paid greater attention to quality.

For editing, I use iMovie for tasks such as combining audio and video, adjusting audio levels, cropping, inserting cutaways, and occasionally removing minor hiccups in my speech. Nevertheless, around half of my videos are uploaded with no processing. A helpful trick is to use a camcorder that can be started and stopped using a smartphone, and thus it is rarely necessary to clip the beginning and end from a video. This simple step saves potentially hours of resaving minimally edited videos.

Video is the natural medium for Millennial and Generation Z students. It is already ubiquitous in their lives and is underutilized in higher education. Amid the tragedy of the COVID-19 pandemic, one body of knowledge that is sure to be created is a trove of best practices in the area of remote coursework. It is my belief that this knowledge will ultimately improve the quality of higher education, long after the crisis has passed.