Pre-production is everything an instructor will do prior to clicking the " Record " button, and is where the most time is spent to produce a video.  At this stage, an instructor will answers questions, such as:

What is the goal of the video?

Educational videos may be to replace a traditional classroom lecture, introduce a subject or chapter, share additional guidance about an assessment, demonstrate a process, or apply knowledge in a real-life scenario.

What hardware will I use to record the video?

Hardware may vary from a Smartphone prompted up against something to a recording studio with specialized camera(s), lighting, microphone, green screen, and a teleprompter.

What software will I use to record the video?

Software depends on the goals of the video and, possibly more important, the video production skills of the instructor.  The simplest video may be generate by a Smartphone's or webcam's software.  While a more sophisticated, interactive video may require advanced software, such as Camtasia or OBS Studio. 

What is the targeted time/duration of the video?

Research has shown that our attention spans are decreasing.  It is recommended to break a traditional 45 - 90 minute lecture into smaller videos, thereby giving students the flexibility to engage in a video when they know they have 3, 8, or 12 minutes to devote to it.

How will the video be delivered?

Experienced video creation experts methods vary from an impromptu monologue with the camera, to a bullet-pointed outline, to a script.  Given an instructor's comfort level behind the camera and experience any of these methods (or a combination thereof) may be appropriate.

Will visual aids be used?

Many instructors use slideshows in their classroom to enhance their lecture.  This same tool may be used to enhance an online lecture.  If so, slide layouts may need to modified to accommodate space for an instructor's image.

As the above questions may stimulate a bunch of thought and even create more questions, it is understood why this is the most time consuming part of the video production process.