Recorded presentation slides should have more text

A lot of advice that I have seen on making presentations with slides recommends not putting enough text on the slide to be useful without the presenter’s speech, ideally just a few words or a picture per slide, with at most around a dozen slides. Having listened to many presentations of various styles, I disagree with that advice.

Slides are mostly used for presentations that are now shared in real-time over video call solutions, prerecorded, or recorded for non-interactive watching in the future. Usually the recipients see the slides and hear the speech concurrently in a multimedia way. If there are no spoken words, then slides are not as useful as an article (other kinds of slideshows might be useful, while they are out of scope of this article and belong to a museum as an animated caption for its exposition). (I had high school assignments of preparing slides where I would not be presenting them and I would not get any feedback; these could have been much more useful.)

(I’m not considering lectures from before the time an overhead projector was introduced. It’s problematic when a student has to copy all text the professor writes on a blackboard and has no remaining thought to comprehend it and ask the professor useful questions. It’s good that movable type and electronic communication were invented so now lectures can use multimedia techniques with materials that students can review before or after the lecture.)

Remote meetings using video call technology add a lot of issues to presentations: like audio quality and network issues (including jitter and complete connection loss). Listeners are more likely to mishear some words which is already an issue when listening to people speaking in the same room.

Currently popular video meeting software also makes slides less accessible: they are often shared as a video of the presenter’s screen. This uses lossy compression often making text blurry. We could instead get a perfectly rendered PDF or HTML slide; possibly the listener could adjust the font size and other visual aspects for their own accessibility needs. (Wearing glasses, I don’t want the uncertainty if I see blurred text due to the prescription being outdated, or due to the video call software introducing artifacts to the text.)

As language is redundant and many words could be omitted preserving the message, we can put a lot less on the slides. However, some things are non-redundant, harder to comprehend from speech and should be displayed on slides. These include large numbers (which we might compare against context and usually hear and forget before the became relevant), dates, acronyms (which I often need to draw with my fingers to recognize from spoken letters; it’s good that people usually do not abbreviate the less obvious ones when speaking) and mathematical equations. In the rare cases when a presentation includes tables or URLs, these obviously should be included (and if they refer to resources on the Web, they should have full URLs for these). Obviously charts need to be shown on slides, their spoken (or written) descriptions are necessary but not sufficient.

Some minimalism is needed in slide design: they should not distract from the presentation. This involves not having typos: use spell-checking software and proof-read the slides before the speech. They should have an accessible color theme, legible fonts with not too small text. (Too big text is rarely an issue, slides are too small to require aerial view like the Nazca Lines.)

It’s also easy to miss short words when listening to a speech; a common example is ‘not’. So a small amount of network issues can completely invert the perceived meaning of a speech. This can be solved by showing the correct message on a slide.

Even with a perfect network people do not listen at 100% of their capacity: they might be distracted (by letter carriers, by power outages, loud neighbors, etc) or tired after hours of work. These make it harder to comprehend every word of a speech. (All regular accessibility issues, experience with the used language and the subject matter affect this.)

As a slide is shown statically for a longer time (even when the presenter reveals the slide line by line while speaking on its topic, the past lines remain visible longer), a listener can check the slide to read what they missed hearing and to consider the previously shown data in a new context.

The advice against reading slides has some merits: a meeting is not needed if it could have been an email (or a blog post) with the slides containing everything and there being no interaction with the presenter; the presenter has to explain the topic in an interesting and a different way than incomplete slides.

The technical presentations I’m most proud of were about a complete document (an explanation of a technical issue or a user story) when every new information that I said was an error in the document requiring it to be fixed after the presentation. The listeners did learn more from these than just by reading the original documents and they contributed a lot of feedback to these. Both the meeting was needed, and the document itself and the fact that I presented it while talking.

So for my future presentations, I will aim for slides or other visual materials that are sufficient on their own while possibly more concise than my usual writing style. I’ll focus on including all the data that I would speak in the slides. And I might need to prepare the slides early enough so I can share them with remote listeners instead of having to screen share.