Giving a talk can be one of the most intimidating assignments for students, working scientists must regularly showcase their research in oral presentations so it’s an essential skill to acquire. And it doesn’t have to be an ordeal, as long as you plan and prepare well.
The structure of a talk describing research results is basically similar to the structure of a research paper, but there are a few important differences. Keep in mind that talks are usually short (10-15 minutes is common) and so you must eliminate some detail, and focus more on the key points you want to get across. Readers can go back over passages which are unclear, or review points they have forgotten, but the audience at a talk doesn’t have this opportunity. They only get one chance to understand what the talk is about. To make it worse, the audiences at many conferences listen to ten or 15 talks each day, and may not be as alert as you the speaker would hope, especially with the lights down for slides. But on the bright side, talks are multimedia presentations. You have visual displays such as graphs, pictures and maps at your disposal, and your own voice to carry the narrative of your story (and answer questions at the end). Used together voice and graphics can be a powerful way of communicating.
Here are some specific tips for preparing and delivering your talk.
Content:
If you have already written a paper on the research you will be presenting in your talk, go back to your abstract to help you focus on the key points of your research. Remember that your talk will need to be simpler than the original paper.
Your introduction should follow the same basic model as the Introduction to your paper (Swales 1984), but you need to provide a somewhat broader background to ensure the audience understands the purpose of your research (Penrose and Katz 1998), and you can omit some of the details of your literature review.
Don’t devote much time to discussing details of your methods. Just try to give the audience an overview of your study so they know how you approached the question. Those who want more details can ask questions after your talk.
Your results should be the main focus of your talk. Discuss them thoroughly and use graphs as an easy and intuitive way to demonstrate the main trends. In talks it’s fine to discuss results while you are presenting them, and it’s often easier for the audience if each trend is interpreted as it is presented.
Organization:
A good way to approach your talk is to remember that you are telling your audience a story, with a beginning that introduces the topic, and previews what is to come, a main body that provides the details and fleshes out the story, and an end that summarizes and draws conclusions. This philosophy is sometimes summarized as: “Tell them what you’re going to tell them, tell them, then tell them what you’ve told them.”
If in doubt about whether to include a piece of information or not, always go back to the big picture. Ask yourself: “What are the main points I want the audience to take away from my talk? Does this information help them to grasp these main points?” If the information doesn’t help tell the story, cut it out. Use the KISS principle wherever possible — “Keep It Simple, Student.”
An outline or overview is an excellent way to introduce the subject of your talk, and let the audience know what is to come. This will make it easier for them to follow the flow of your talk. Similarly, conclude your talk with a review of the main points you have made (the infamous take-home message).
Style:
Graphics are the most powerful tool you have available to help tell your story. They can include graphs of key results, pictures of your study organism, or maps or photos of your study area. Don’t neglect this part of your talk, but remember that quality is more important than quantity.
Try to integrate graphical elements with your narration. If you display a picture, tell the audience what you expect them to get out of it. In particular, take the time to carefully go through graphs of key results. Note what the axes show, and tell the audience the key trends the graph displays. You are familiar with the graph and the information it displays, but it’s new to the audience, and they need time to absorb it.
Make the text on any slides or overheads you use large enough to be readable from the back of the room. Text looks much bigger on your computer screen than it will to your audience. Eighteen point is the smallest type you should consider using in most circumstances, and 24-32 point is better.
Don’t fill your slides with text (or numbers). Not only will it be hard for some people to read, it will be a distraction from you the speaker. Text should accentuate key points, not tell the whole story.
Try to make eye contact with the audience. A personal connection will help keep their attention, and watching their facial expressions will give you instant feedback on whether they are following you. Never turn and face the screen or blackboard for extended periods. And speak with enough volume to reach everyone in the room.
The best way to deliver a talk is to use brief notes. Reading from a prepared script results in wooden delivery and makes eye contact with the audience difficult. Memorizing the entire talk is labourious, and also typically results in poor delivery. If you know your material well, and know what you want to say about it, all you need are short notes reminding you of what point comes next. As you gain experience, you will find you can use your slides to provide these memory cues, eliminating the need for notes entirely.
Practice your talk ahead of time. Practice in front of friends or family if possible, or in front of a mirror if no one is available. This will help your delivery, smooth out rough places, and help you pinpoint your timing. Many conferences are ruthless about enforcing time limits for talks, and nothing is more frustrating than getting pulled off the stage just as you are about to reach your conclusion.
Relax. Scientific audiences may be critical of results, but they are generally courteous and attentive, and they recognize that you are not a professional public speaker. They want to hear what you have to say. One of the biggest problem students have in presentations is nerves, which can cause you to speed up delivery, and skip important points.
Know your subject well, and be prepared for questions after your talk, but don’t be embarrassed to admit it if you don’t have the answer. One of the main reasons we give talks is to get new ideas and new ways of thinking about our research from others.
Technology:
Historically, slides have been the most common graphic format used at scientific conferences. Slides are versatile and allow high quality colour images, but are also expensive and time-consuming to produce.
Overhead transparencies are easy to prepare and use, and many modern inkjet printers can make good quality colour transparencies. Overhead projectors are powerful enough to work in a reasonably well lit room, which is convenient if you want to allow questions during your presentation, or move from overhead to the blackboard.
Computer presentations using programs such as Microsoft’s Powerpoint or Corel’s Presentation Manager are fast becoming the method of choice for delivering scientific talks. Once the software has been mastered it is quick and easy to produce a wide range of high-quality graphics, and last-minute changes don’t require a trip to the printer or photo shop. However, they do have some drawbacks. The data projectors used to project the information on a screen are generally not as powerful as slides or overheads, and this can make presentations difficult to view in rooms which are large or partially lit. Compatibility issues both at the hardware (PC vs. Mac) or software level can leave presentations distorted or completely unusable.
Blackboards, whiteboards or other low-tech tools can be effective, especially for informal presentations. Experienced presenters use writing on the blackboard as a way to slow the pace of their talk so the audience can keep up. Unless you’re comfortable in front of an audience, and have some artistic ability, it’s best not to plan on drawing complicated graphics during your talk.
Whatever technology you plan to use to deliver your presentation, check ahead of time with conference organizers or your instructor to ensure that facilities and equipment is available. Don’t assume, or you may find yourself delivering your talk without any graphics whatsoever.