One of the Keys to a Good Presentations is...

One thing (amon many) that bothers me during a presentation is a lack of consistency between graphs. Perhaps I’m just being a bit anal here, but it seems to me that talks should be designed so as to allow the listener to grasp what you are trying to say as quickly as possible. If the audience has to work too hard to understand a series of graphs, then the audience will stop paying attention.

Now I’m not talking about colors and fonts, although maintaining a consistent color scheme for data sets throughout a talk is a very good thing. (If you use red for sample #1 and blue for sample #2 on the first slide, keep it that way throughout the rest of the talk. I know that seems fairly obvious, but you’d be surprised how many people don’t pay attention to this. Far too many people who should know better just use whatever colors Powerpoint gives them.) No, I’m talking about inconsistencies in the way the data is plotted. For example, plotting some of your data using weight% and others using mole% (unless there is some special reason for doing so.)

This almost always happens because the presenter is too lazy to convert one (or more) of the plots. I’ve seen this at group meetings at work as well as at talks given at our local catalysis society meetings. In these cases, it’s obvious the presenter just tossed in a bunch of plots drawn by their students (or group members) and figured that was good enough.

I bring this up now since my current project involves lots of meetings with lots of presentations with lots of data and we’re running into the same problem. In this case, the problem stems from a lack of an agreed upon format. We work on fuel cells and it’s common to evaluate a cell by measuring its current output as a function of voltage. It’s called a polarization curve and is commonly plotted as amps versus voltage. That’s fine, but we have people from many different backgrounds - materials people, electrochemists, product engineers, graduates students from a local university, PhDs from one of the national labs – and everyone has their own preferences. Some like to plot watts (amps x volts) versus volts. Others plot current density (amps/cm2) versus volts while still others plot power density (watts/cm2) versus volts. If that wasn’t bad enough, sometimes the axes are flipped, so that voltage is now on the y-axis. And when they start mixing up these plots in their project updates – and they always do -- I spend half my time doing conversions in my head, just to figure out what the data really means.

So please keep your plots consistent. I may be in your audience one day and I’ll greatly appreciate it!

I would also like to apologize for the long delays between posts. I promise to start posting more often, like I used to do.