A Comprehensive Guide for Public Speaking at Scientific Conferences


I served as a judge for some of the student presentations at the 2016 Canadian Statistics Student Conference (CSSC).  The conference was both a learning opportunity and a networking opportunity for statistics students in Canada.  The presentations allowed the students to share their research and course projects with their peers, and it was a chance for them to get feedback about their work and learn new ideas from other students.

Unfortunately, I found most of the presentations to be very bad – not necessarily in terms of the content, but because of the delivery.  Although the students showed much earnestness and eagerness in sharing their work with others, most of them demonstrated poor competence in public speaking.

Public speaking is an important skill in knowledge-based industries, so these opportunities are valuable experiences for anybody to strengthen this skill.  You can learn it only by doing it many times, making mistakes, and learning from those mistakes.  Having delivered many presentations, learned from my share of mistakes, and received much praise for my seminars, I hope that the following tips will help anyone who presents at scientific conferences to improve their public-speaking skills.  In fact, most of these tips apply to public speaking in general.


I spoke at the 2016 Canadian Statistics Student Conference on career advice for students and new graduates in statistics.

Image courtesy of Peter Macdonald on Flickr.

Before the Presentation

Many of the problems from bad public speaking stem from bad preparation.  Here are some tips for preparing for a presentation.

  • Ensure that your abstract has proper spelling and grammar.  I was aghast at the abundance of blatant mistakes throughout the abstracts that were written in the program booklet.  There is no excuse for these errors – they are short pieces of writing, and you have plenty of time to proof-read them.
    • Your future employer may search your name on Google and find your writing in a document like this, so any mistakes that you leave in such a public record will reflect on your poor diligence and inability to write in proper English for the rest of your professional life.  Be ruthlessly attentive.
  • Put one or two key concepts on each slide, but no more.
    • Your audience will be listening to you and reading the slides at the same time, and it will be very hard to pay detailed attention to both.  Don’t overwhelm them with too much information on a slide.
    • Your slide should complement what you say, not completely substitute for it.
    • Equations and formulas are especially difficult to absorb, so show only one on each slide.  Only show more than one if they are directly related or comparable to each other.
    • Spread the text and images with plenty of space apart so that they are easy to distinguish from each other.
    •  Put more than 2 concepts on a slide only if it is meant to be a list.  For such slides, make sure to spend some time talking about each item on this list.  This will allow the audience to absorb each item fully as you expand on it.
  • Write information in point form.
    • Don’t write paragraphs on a slide.  It’s too hard to absorb their content.
  • Use succinct phrases whenever possible.
  • Use an online LaTeX editor to write your mathematical expressions, formulas, and equations.
  • Use plots and diagrams whenever possible.
    • Statistics, math, and science are very visual subjects, and images will greatly facilitate your audience’s understanding of your concepts.
    • PowerPoint has many tools for drawing diagrams.  Use them well.
    • Label and annotate your plots properly.
      • Ensure that you label your axes and include units.
      • Insert legends whenever needed.
      • Use large markers and thick lines to make your plots visible to everybody, especially those who will sit in the back of the room.
    • Wikimedia and Flickr has many stock images that you can freely use, but make sure to check the licensing policy of each photo.  Attribution is often necessary and a good thing to do.
  • Tables and arrays are also valuable for organizing information.  Use them whenever possible.
  • Generally, use black text against a white background to make your writing clear to everybody, especially those who will sit in the back of the room..
    • Use colours, bolding, italicization, underlining, and varying font sizes to make key distinctions between adjacent text or highlight important points.
  • Include a slide to highlight your online profiles, such as your web site, blog, LinkedIn profile, Twitter profile, or YouTube channel.
  • Practice delivering your presentation.
    • Mark the key junctures of your speech, and make sure that you have enough time to hit each of those junctures.
  • Ensure that you can finish your presentation within the allotted time.  Far too many students in the 2016 CSSC did not finish delivering all of their intended material, which reflected badly on their organizational skills.
    • If your practices reveal that you don’t have enough time, then cut material from your presentation.
    • Instead of presenting all of the details of a particular step, just state the conclusion.
  • Rehearse your presentation in front of a respectful but critical audience.
    • If you are a university student, ask your department to organize a rehearsal session for all students who will present at the same conference.
    • Offer to help to organize this rehearsal session.
    • Invite professors, research staff, graduate students, and undergraduate students to attend this rehearsal session.
    • I thank Hugh Chipman of Acadia University for suggesting this valuable tip.
  • Try to frame your slides and speech into a story.
    • Humans absorb stories much better than a collection of disparate facts.
    • This is relatively easy to do when you present your research.  A story has a beginning, a middle, and a end.
      • The beginning is your initial question or objective.  What motivated it?  Why is it important?
      • The middle is your actual work.  How did you tackle your research question or objective (i.e. What was your methodology)?  What obstacles did you face?  How did you overcome them?  What surprises did you encounter along the way?
      • The end is your conclusion.  What is the answer to your question?  What did you learn?  What is the moral of the story (i.e. How does your work impact your overall field of study?)
  • Many people put a slide at the beginning to provide an outline for the rest of the presentation.  I don’t do this for two reasons.
    • Most presentations in math and science follow the same general scheme, so it doesn’t add much value and wastes precious time.
    • If you create a good story for your speech, then your audience will be captivated from the start, and providing an outline would spoil any surprises.
    • I recognize that this is an unusual opinion, and it fits my very unique style of presenting technical seminars.  Thus, use an outline slide if it is really important to you.

I delivered a very technical presentation to the Vancouver SAS User Group in 2016, and I received many positive comments from the audience afterward.  I discussed the use of ANOVA to assess a sampling scheme for quantifying sodium in potato chips in analytical chemistry.  These slides illustrate many of the principles that I talked about in this section.

This is a slide from my presentation on ANOVA and sampling in analytical chemistry to the Vancouver SAS User Group in November, 2016. Note my use of colours, arrows, and an image to illustrate my concepts on this slide. Remember – slides should complement your speech, not substitute for it.


During the Presentation

  • If possible, bring a video-recording device (such as your smartphone or tablet device) with you, and respectfully ask someone in the audience if they would be so kind and willing to record your presentation.
    • Use something like a book to prop the device, so that your kind Samaritan doesn’t need to hold the device throughout the whole presentation.
    • This recording will be very useful for you to watch afterward and review your performance.
  • Speak from memory, and DO NOT read from a script.
    • Talking to your script without looking at your audience is very impersonal, and it obliterates the human connection that makes public speaking a powerful way to connect with people.
    • Practice your speech ahead of time and use your slides as a guide for what to say.
  • Make eye contact with your audience.
  • Your intonation and facial expressions are your tools for connecting with your audience.
    • Vary the tone of your voice.  Speak loudly at important points.
    • Vary the pace of your voice.  Speak slowly at important points.
  • Pay attention all sections of your audience.
    • If possible, walk laterally throughout the space in the front of the room to accentuate your attention to each part of the audience.
  • Use your hands and arms to gesture and emphasize any key points.  They are highly undervalued tools in public speaking, and using them wisely can energize your presentation significantly.  Watch my videos on my YouTube channel for some examples of how I do this.
  • Consider demonstrating something in another software or programming language, like RStudio, SAS, JMP, Python, or MATLAB.
  • Ask questions occasionally throughout the presentation to engage with your audience through their participation.
    • Ask questions on points that deserve emphasis and require some thought.
    • This strategy works best when, after you ask the question, a brief, awkward silence falls over the audience and forces them to start thinking and talking to break that awkwardness.  When executed well, this is one of my best techniques for public speaking.
    • Sometimes, an occasional question to force the audience to remember some basic fact near the beginning of the presentation is also helpful.  This forces them to pay attention right from the beginning.


Eric Cai YouTube hazard function

Visit my YouTube channel to view more examples of the public-speaking techniques that I mention in this article.


After the Presentation – Questions and Answers

Most conferences will allow the audience to ask questions and answers after you finish presenting.  Your job is to answer the questions as substantively and as succinctly as possible, so that the number of questions is maximized.  This is not easy.

Here are some tips.

  • If question cannot be clearly and loudly heard throughout the entire room, then use your microphone to repeat the question to the entire audience.  (It may be helpful to ask the moderator to remind your of this.)
  • It’s OK to pause, compose your thoughts, and prepare your articulation before you say the answer out loud.
    • As the speaker, you are in control of the tone and rhythm of the conversation.  Don’t be afraid of some awkward silence.
  • If the audience member asked multiple questions, then point that out, and answer one question at a time.
  • Answer each question with the minimal number of words.  As soon as you finish your answer, stop.  Move onto to the next question.
    • Sometimes, an audience member may expend many words to ask a question.  That does not necessarily merit a long-winded answer.
    • An efficiently worded answer may be the best answer to a verbose question, but the imbalance may be awkward.  Do not let that awkwardness push you to speak longer than necessary.
  • Pay close attention to what is being asked.  Hopefully, the audience member articulates the question well with proper English, and the following words will become reasonable guides for how you answer.
    • “What” asks for a thing.
    • “When” asks for a time.
    • “Where” asks for a location.
    • “Why” asks for a reason.
    • “How” asks for a method, a technique, or an approach.
    • “Do”, “Does”, “Is”, and “Are” ask a Yes/No question, so answer with a “Yes” or “No”.  If the answer is not self-explanatory, then offer an explanation.
    • These guides are not strict, but they are useful and generally work well.
  • If an audience disagrees with you on substance or points out a mistake, then respond substantively by addressing the issue with honesty and integrity.
    • Don’t interpret it as a personal attack.
    • Don’t reply with a vengeful tone.
    • If you made a mistake, then admit it right away.
    • If the disagreement has substantive value, then acknowledge it right away, and give the audience member credit for offering that contrasting perspective.
    • If you sincerely disagree with the assessment, then say so, and do it substantively, but not resentfully.
  • Write any useful notes from the question-and-answer session into your note book.


After the formal question-and-answer period is over, audience members may come to talk to you on a one-on-one basis afterward during a break.  If your presentation was great, many people may wait in line to talk to you.

  • Before you talk to them individually, consider getting some water or food to replenish yourself.
  • When speaking to each new person, firmly shake their hand, make direct but friendly eye contact, and ask them for their name.
  • Just like before, answer each question with the minimal number of words.
    • As soon as you finish your answer, stop.  Thank them for coming, and move onto to the next person.
    • Do not allow one person to monopolize your time.  Allow others to talk to you.
    • Once you have talked to everyone, then feel free to circle back to the first person and allow them to ask a second question.

Do you have any other suggestions for public speaking?

If so, please share them in the comments below!


4 Responses to A Comprehensive Guide for Public Speaking at Scientific Conferences

  1. Dexen Xi says:

    For very short talks (e.g. contributted sessions), a better direction for the presenter to take when creating his talk may be to focus on delivering couple main messages he has discovered from his work, instead of trying to summarize everything he has ever done. This way he may be able to get away with the burden of constructing a full story. Attempting to tell a full story in a very limited amount of time is a mistake, and it is often made by brilliant or hard-working students who have done a lot.

  2. Indeed a perfect and comprehensive guide for Public Speaking. Your site is really helpful, definitely learned a lot from this post. Great blog.

Your thoughtful comments are much appreciated!

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