"Show your work" is not needed in presentations

At a recent workshop, one of the participants raised the point that the reason so many people put all the data on their slides is that in school we were always told to "show your work." Our kids are just finishing their school year and I agree that it is important in school to show your work. Otherwise, the teacher can’t evaluate whether you really know the material or not. If you just show an answer, they don’t know how you got the answer and can’t be assured that you grasped the concepts they were teaching.

But the workplace is different. As professionals, our presentations are not an attempt by our bosses to check if we know our job. They do that evaluation before they ever hire us. If we couldn’t do the work, we wouldn’t get the job, it’s as simple as that.

Your presentations are to present the result of your work in a way that enables others to use the information to make decisions or use the knowledge to be more effective and efficient in their own work. If you show all the background and data, you lose the audience because it is overwhelming. There is so much coming at them, they don’t know what the most important point is. And they give up trying to figure it out, or, even worse, come to a different conclusion than the one you wanted them to reach.

Instead, present only the conclusions from your work and in a way that clearly shows the meaning of the analysis to this audience. Always be thinking about what the audience really wants to know from you. They don’t want to know all the work you did, they only want to know how the conclusion will impact them. Feel free to have backup or Appendix slides that contain more details in case someone wants to see the details, but don’t include those slides in the main part of your presentation.