Pros and cons of including mathematical equations in presentation slides

Question

As a researcher in CS, I give often presentations, where I always ask about the feedback from my colleagues. I personally don't like to put equations in my slides because I believe that nobody will have enough time to read the understand the equation (especially because in CS the equation is a tool to solve the problem and not the heart of the topic). Instead, I enrich the slides with intuitive figures and demonstrations. I've heard some professors encouraging the same approach, but in my current group, my professor and my colleagues believe that equations illustrate the complexity of the method and we should put them.

I don't think this is a question of preference, therefore, I would like to have more opinions about putting or not putting equations in presentation slides and why.

Answer 1

You are starting from the wrong point if you are asking the question of whether to use formulas in isolation.

When you write a presentation, a paper, a proposal, an expose, or anything else, here are two questions you should ask yourself:

• Who is my audience? What is their prior knowledge? Why are they there and what are their motivations for attending/reading? What do they want to take away from you provide them with?

• What is my own motivation? Do I want to teach them something new? Do I want to illustrate how smart I am? Do I want to give an overview of a field that everyone in the audience should understand, or do I want to impress a few key people?

If you have answers to these questions, then (and only then) should you start writing. You will find that, maybe unsurprisingly, the question of whether to use formulas will have different answers depending on your audience and what you want to achieve. If you are giving a job talk and you want to provide depth to your talk, then formulas are probably a fine approach. If you are giving a department colloquium that should have broad appeal to grad students and professors alike, then maybe using words instead of formulas is the better approach.

The point is: It all depends -- on the audience and what you want to achieve.

Answer 2

Ultimately, it boils down to a question why people do presentations. In your text I see two reasons:

• presentation is the way to explain your research and results to others;
• presentation is the way to show other how complex is your research and how difficult was it to obtain and understand the results.

People who are mostly inspired by the latter tend to show how much they know about the subject.

People who have mostly the first motivation think about how much their audience will learn about the subject.

I personally believe that the success of the presentation (or a class) is measured not by how much you told, but how much the audience received from you. So I side with your approach — keep long formulas to papers and only use short equations and a lot of visuals in your slides.

Answer 3

I teach in a mathematical field (statistics) and I always encourage my students to minimise equations in their presentations, and never present equations that they are not going to go through and explain clearly to the audience. Sometimes basic equations showing your model form are useful, but sometimes you can give an explanation without the aid of mathematics. In any case, you should only show equations if they assist the audience in understanding your work, and if you are willing to take time in your presentation to go through each equation and explain it.

Including mathematical equations in a presentation solely to "show the complexity of the research" (i.e., show off) is academic masturbation. It bamboozles the audience for the purpose of aggrandising the speaker. Don't do it --- push back on their suggestion to the contrary.

Answer 4

I find that in addition to other concerns, the time spent per slide is a significant factor. For example, some people zip through a slide every minute or two: obviously that's two fast for anyone to digest a complicated equation. On the other end of the spectrum, conceivably one could give a presentation with one fixed slide showing for the entire talk, and this would be a fine strategy for highlighting one particular equation which is the focus.

Using slides in my lecture courses, the ideal situation is to have a theorem/equation on a slide and then also some exercises, so that everyone is viewing/reflecting on it for an extended time. In college algebra and below, I use just a single slide every 30 minutes, and that works out fine. That's not exactly your use case, but it highlights my point: the more time you're willing to spend on a particular slide, the more reasonable it is to be considering an equation on it.

Answer 5

I struggle with this question myself. This is not a philosophical answer, but two practical tips that might be of use for making presentations in LaTeX:

• It is quite easy to make buttons that link to another slide (for Beamer, see end of this page; I believe also possible in PowerPoint). So, you can make high-level slides and add a button called "details" that links to an equation slide. That way, if someone wants the technical background, it is easy to reference and pull up. I think this is a way to show you are prepared for detailed questions without having to cover all the math.

• When I do include equations, I like to use \underbrace and \overbrace to write in words what the different parts of the equation mean like so. This could make it easier to follow, particularly if people get confused by the notation.