Data scientists often sabotage their own work by doing a crappy job of presenting it. Don’t fall into this trap: think carefully about what you want to say, and build PowerPoint decks (*) that say it well. Data scientists often present their projects the same way that they present in a seminar or at a half-empty session at an INFORMS conference: LaTex decks with a white background with twice as many slides as minutes to speak. Your words will fall on deaf ears if you present this way. Polished presentations need not be superficial! Tuck in your shirt and create a nice looking deck. Here’s how.
Focus on three key messages that you want your audience to understand. Orient your presentation around those. Who is your audience? Are they peers? Decision makers? New team members? Clients? Three points well suited for one audience may not be relevant for another. This often means re-working a perfectly good deck, or leaving fascinating conclusions unsaid. Do your audience a favor and tell them what they need to hear, not what they want to hear, or what you want to say. If you haven’t touched on your three main points within 5 minutes (regardless of the length of the presentation), you’ve done something wrong. I screw that up a lot.
Analytics practitioners are often in the happy situation of having too much to say. We tend not to talk about fluff, but we take it too far in the other direction. 50 slides for a 20 minute talk is too many. Depending on the topic, five, three, or even one may be enough. It’s a judgment call, but err on the side of leaving things out. You can always stash extra slides in an appendix in case the conversation leads that way, or you miraculously end up with time to spare. Nobody will measure the value of your deck by the number of slides, but by the amount of useful, relevant material.
Your presentation should tell a story. It should have a beginning, a middle, and an end. This story may be told through your verbal presentation rather than in the deck content itself. Storytelling is particularly important because your audience will not pay full attention to what you are saying, nor will they read your deck carefully. It’s not a TED talk. They will stop paying attention 5 minutes in, and rally at the end. While your presentation has been the focus of your day (or perhaps week, month, …), that is usually not true of your audience. They’re thinking about what they want on their pizza later.
Be clear, and tell the truth. Don’t sugar coat or hide from your findings. Data scientists are careful people because we don’t want to overreach, but if you add ten qualifiers to every sentence then nobody will know what the hell you are talking about, and won’t care. Call out things that are important. You can say, “This is important.” You can say, “We’re not sure about this.” You can say, “This is not what we expected.” You can say, “This is obvious.” If you can’t admit what you don’t know, then people will suspect that you don’t know what you actually do.
You will not always be around to explain your deck. Decks are passed around and read by people you have never met, if you are lucky. Their half-life can be months long. Slide titles should guide readers along without supervision. Callouts can refer readers to other resources. Stick extra slides in the back for definitions and additional supporting material if needed.
The written tone of your deck should fit the content and your audience. In particular, these considerations should govern the amount of technical detail in your deck. If the math is what’s at issue, then your deck should have equations in it. If not, then leave them out. They are often the mechanics rather than the meaning. Try to make the deck self-contained without being burdensome: include variable definitions and define acronyms the first time you use them. Avoid Greek letters unless absolutely necessary. In general, LaTeX should not be used in a PowerPoint deck. Use PowerPoint’s “math mode” (control-equal in recent versions) so that the content is editable and can be changed the appropriate size and resolution. If you need LaTeX’s more elaborate equation formatting, consider whether you are loading in too much detail for your audience, or whether a deck is the right delivery vehicle.
Don’t simply read from your slides. There is no point in you being there if that’s all you’re doing. Your deck should be written (and you should know the material well enough) so that the slide content serves as cues for you to say what you need to say in a natural, succinct way. Practice, with a friend or by yourself. Record yourself and watch the recording if you have never done so. Be yourself, unless you are by nature inappropriate. In that case, pretend to be somebody respectable. Most people are not funny, at least to the majority of a large group. Consider leaving jokes out of the PowerPoint deck entirely, and if you must use humor, simply weave them into your verbal presentation. It’s best if the humor is natural and not pre-canned. Be culturally aware. Avoid pop culture references and American English idioms if you have a global audience (you usually do). It’s hard to avoid this completely, but if a few slip out then that ends up being your personality shining through rather than confusion and awkwardness.
Be obsessive about the visual elements in your presentation. Pretend you are Steve Jobs. If your organization has a standard PowerPoint template, use it. You are speaking on behalf of your organization and part of your job is to serve as an ambassador. Save the iconoclasm for twitter. If your organization has style or voice guidelines, use them as well, so long as you are able to do so naturally. No organization wants you to come off as a phony.
In most cases, the following principles apply:
- Don’t overdo fonts. Three sizes and two typefaces should suffice most of the time. If one of them is Comic Sans, quit while you’re behind.
- The use of color is a good thing as long as it isn’t overdone. In this sense it is similar to the use of italics and boldface. If you use it too much, or in long stretches, it begins to become annoying. Consider the use of common user interface metaphors when using color: blue is cold, red is hot, and so on.
- Using icons instead of words can be effective.
- When referring to your company’s logos, brand names, slogans, etc, make sure you are using the most up-to-date, correctly spelled versions possible, derived from original sources. You’d be surprised how often this is botched. Be even more careful with client, partner, or competitor logos and names. Get permission first.
- Less is more. Delete unnecessary words such as adjectives and technical jargon.
- Avoid bullet point slides. Consider tables, charts, or visual evidence to make the same point.
- Be obsessive about alignment and positioning. If you have tables of similar size on consecutive slides, they should be in the exact same spot. Make sure centered elements actually are centered. Titles are in the same spot. The same font size is used for similar elements through out. Use the “Size and Position” settings in PowerPoint.
- Tables should have appropriate cell margins, and align data correctly. For the love of Tufte, don’t left align numeric data. Use a consistent and appropriate number of decimal places.
- Follow an authority like Tufte for charts (but avoid his twitter feed). Label the axes, and always provide units. Use appropriate scales. Be information rich.
- Be careful with stock images and clip art. If often looks dumb, and it dates very quickly. Make sure stock images and clip art illustrate an actual point you want to make rather than fill space.
- Forget animation. It’s usually not worth it, and it is often a distraction.
- Last thing: try to find as many opportunities as possible to present a deck, and modify the deck after every presentation.
All of this advice is subjective and you may come across occasions where doing the direct opposite of what I suggest is the right thing to do. That’s okay. The key is to be as intentional about the way we present our work as we are about doing it.
(*) I say “decks” and not “whitepapers” or “documentation” because PowerPoint decks are the primary information currency for many organizations. I say “PowerPoint” rather than <your favorite presentation software> because the reality in 2013 remains that PowerPoint is the standard for most organizations. You can argue about whether these things should be, or whether they will change, but they are realities just the same. Don’t let your opinions about such matters get in the way of delivering your message.