My Purdue colleague Nicole Devlin started a YouTube channel called TL;DR engineering to explain first-year college engineering principles in concise but vivid ways. The videos are captioned! Here's how she captioned them.

  1. Recorded high-quality audio.
  2. Used YouTube autocaptions (which are automatically generated).
  3. Then -- and this is a crucial step, because the autocaptions were not accurate enough to learn from -- she manually edited the captions for accuracy, using these instructions from Google.

...and that was it! The video is now more accessible to:

  1. International students and non-native English speakers
  2. Deaf and hard-of-hearing students and those with auditory processing disorders
  3. Students working in a library or other quiet place without headphones, or watching from their phones
  4. Students who want to scroll through the transcript to find a specific word or section
  5. Web search engines (making her videos more search-engine friendly)
  6. ...and more.

If you want to go even further into caption ninjahood with very little effort, you can edit the caption breaks so they display sentence-by-sentence rather than 3-4 words at a time. This might seem trivial, but it means that you can read an entire thought at one time -- which means you don't need to hold the rest in memory. Imagine reading a book where each word was on a separate page. You'd turn the pages really, really fast (meaning you don't get to see a word for very long), and you would have to hold each word in memory until the thought or sentence completed.

This is less complicated than it sounds. For instance, the current transcript of one video has...

Choppy text
1:00 Laminar flow is the opposite of turbulent flow,
1:03 it's very smooth and regular like when honey flows...
1:07 every molecule has its place. If we look at the Reynolds number for honey,
1:11 the viscosity is very high and
1:15 velocity is very low, which leads to a low
1:18 Reynolds number and laminar flow.

With very little editing, this can become...

Smooth text
1:00 Laminar flow is the opposite of turbulent flow.
1:03 It's very smooth and regular, like when honey flows. Eery molecule has its place.
1:08 If we look at the Reynolds number for honey, the viscosity is very high and velocity is very low,
1:15 which leads to a low Reynolds number and laminar flow.

And that's it, folks. Caption your videos! It's a small one-time job for you, and a long-term higher impact for everyone. Thanks to Nicole for being a great example and captioning hers!