Speak your science: How to give a better conference talk, Part 1

Part 1 — Part 2Part 3

Today, we have the first of three cross-posts by Emily Lakdawalla, the Senior Editor of The Planetary Society. Emily is an internationally admired science communicator and educator. She holds a Masters degree in planetary geology from Brown University, and will release her first book this year.

You can find Emily’s original post from The Planetary Society here.

Figure 1. Emily Lakdawalla giving a talk at The Planetary Society.

Bad presentation often gets in the way of good science. It’s a shame, because science is awesome. I used to complain about bad presentations at conferences but I realized that (1) I hate complainers and (2) as a professional science communicator I should probably quit complaining and actually offer people some help with communicating better. If you’re a scientist who’s interested in improving how you present your science, read on.

If you don’t have time to read, I can summarize my advice in three words:

Respect your audience.

Each one of the people in your audience is another person, like you. Their time is as valuable as yours. Work to deliver them a presentation that is designed for them, to inform and interest them in your work, to leave them pleased that they spent that 5 or 10 or 50 minutes of their valuable time listening to you.

Here are some questions to guide you in preparing a good talk.

  1. To whom are you speaking?
  2. What do you want them to learn?
  3. What is your story?
  4. How long do you have to speak?
  5. What visuals will serve to amplify your story?

Let’s take these questions one by one.

To whom are you speaking?

Think carefully about your audience. Who are they, and what can you assume about what they already know about your topic? Is it an audience of your peers within your subspecialty? Is it space scientists more generally? Is it scientists and engineers? Is it a funding body? If it’s the public, do they come to the room knowing a lot about space? Or is it a general audience?

The wider an audience you are addressing, the more context you will need to provide to them. If you do not provide the people in your audience with information that they require in order to understand you, it is the same as telling them that you do not care if they understand you or not.

For a scientific conference, I suggest targeting your talks at an audience that is familiar with the scientific process, but whose subspecialty is entirely different from yours. Are you an astronomer? Pitch your talk to a geologist. An experimenter? Pitch your talk to a theoretician.

Really good speakers are ones who manage to communicate something to everybody in the room, no matter who they are or how much they already know. To the relatively uninformed, you should at least answer: what is the question behind your work, and why is it important? What did you learn, and why does it matter? At the same time, to the well-informed, you should convey how your work has added to or broadened or contradicted what has come before it.

Identifying your audience allows you to identify what words are jargon and what are not. Words are wonderful things, and our subspecialties have a lot of vocabulary that is dense with information. But if a word is not familiar to your audience, it will obfuscate rather than clarify. Sometimes a jargon word is unavoidable; it may be the focus of your presentation. In that case, take care to define it more than once through the course of your presentation, and reinforce your teaching of the jargon word with context.

Acronyms and initialisms are a special class of jargon. It’s easy to fall into a bad habit of using acronyms. They are often the most important nouns in your presentation. But unlike in a paper where you can define it and people can look back if they forget what it means, there is no way to “look back” in a talk. I have attended many talks in which a TLA* is defined in the first moment — a definition that I missed because of a trip to the bathroom or just a moment of inattention — and I am lost for the rest of the talk. Really, it often takes no more time to speak the words than to speak the letters.

(*TLA = Three Letter Acronym)

What do you want your audience to learn?

It amazes me that people prepare talks without ever asking themselves this question, but they appear to. A lot of people spend too much time describing their research methods — what they did, and what their data look like. It’s easy to understand why people make that mistake: what you did is, after all, what you spent most of your time doing. But the whole point of your research effort was to learn something that you could then communicate to others. There’s no need to force your audience to endure the same tedium. You can save your audience all that work by telling them what it was you learned.

Here’s an exercise that I highly recommend: Compose a Tweet summarizing your talk. It needn’t have perfect grammar, but it needs to be a sensible statement. In that limited space, you are not likely to say a whole lot about your methods! “I mapped clay minerals on Mars” describes what you did, but not why, or what you learned from it. “Large areas of Mars experienced rainfall over tens of thousands of years.” Cool.

Make that Tweet your conclusion slide. Make sure that your talk builds to that conclusion. How are you going to do that? Well….

What is your story?

It is impossible to overemphasize the importance of narrative in a talk. You, standing up in front of an audience, are telling a story in which you are the principal character. Stories are fun. If you tell a good story, you hook your audience and then they will willingly follow you even into dark corners of your subspecialty.

Stories are also functional, especially for people in the audience who may be struggling to follow you on that journey. If, for example, you have managed to tell your audience that this is a crime story, pretty much everybody in the room should be able to understand what the crime was at the beginning of your talk. Then, if you lose them while you’re talking about evidence gathering, you still have a chance of picking them back up again when you tell them: that was the evidence, and this piece of evidence led me to the perpetrator. Even if an audience doesn’t get spectroscopy or understand what a general circulation model is, they probably get how crime stories work.

Maybe you are not solving a mystery, but are instead an intrepid explorer who has gone to a place no one has gone before. Maybe you have fought a pitched battle with a legendary monster of a data set. (This is a great framework for a presentation about a null result; you get to be the tragic hero.)

Narrative is not just helpful to your audience; it’s helpful to you, too. It provides a structure for your talk, and helps you determine what is crucial to conveying your message, and what is not. Which is very important when you consider the following question:

How long do you have to speak?

You cannot say all the same things in a 15-minute talk slot as in a 1-hour colloquium. You just can’t. Don’t even try. However, you can tell the same story, which is why I put “story” before “time limit” in this blog post. Do you have a favorite novel that’s been made into both a miniseries and a movie, and maybe even a 1-hour show? Think about the differences in story among these. As you go from longer to shorter versions, you see reductions in characters; in settings; in subplots; and finally in the main plot line itself. Yet the story (usually) remains recognizable. Exactly the same process is necessary to go from a scientific paper to a colloquium to a long conference talk to a short conference talk.

It is especially important for very short talks (like at the Division for Planetary Science meeting, where the slots are only 10 minutes long, meaning 6 minutes for speech) to practice your talk and then, if it is too long, cut out information that is not needed to tell your story. Think of the poor audience, especially the undercaffeinated, the jet-lagged, the many people in our highly international community who are interpreting your spoken words as a second language. You cannot solve the problem of a too-long talk by talking faster. Simplify the story that you are trying to tell.

Some people solve the problem of a too-long talk by running over time. Do not do this. It is incredibly disrespectful to your audience.

If you talk through the time intended for discussion, the message to the audience is: I am here to talk to you, not hear from you. I do not care whether you understood my talk.

If you run into the next person’s time, the message is worse: I believe myself to be more important than the next speaker. I also believe myself to be more important than the entire audience’s opinion about which talk they intended to be watching during the time slot I am usurping.

Some senior men seem to regard this as a game, laughing about their battles with the session chairs over getting off the stage. It is not funny, and people are only laughing along because you are senior and hold the power. The session chair has to choose between looking like a jerk or laughing while they try to get you to abide to the rules you agreed to. Don’t be that jerk. Got it?

It is only now, once you have identified your audience, your take-home message, and the shape of your story, that you should begin to think about making a PowerPoint presentation.

About Astrobites

This post was written collectively by multiple members of the Astrobites team. Meet the authors of Astrobites.

Discover more from astrobites

Subscribe to get the latest posts to your email.


  1. As I was studying Geology at the U of Arizona, I came to realize that my killer Boston accent was gaining more attention than my talk, so I signed up and took an undergraduate public speaking course – more then anything else, it made me conscious of most of the suggestions in this bite and the more obtuse parts of my accent. It also improved my ability to read copy so I could prepare my talk on paper and not sound like I was reading. Subsequent I gave many talks to large audiences all over the U.S. with the confidence I would not otherwise have had. ( This is the long story, the short one reads – take a public speaking course, it will serve you well !)

  2. This is a good post (part one) that hits all the mechanical hi-lights of public speaking. There is one element missing in this part and one crucial in holding an audience and holding your credibility as a speaker.

    I’m going to bury my lead here just a bit and give you a little anecdotal experience from an individual who has sat many a doctoral defenses and scientific presentations from graduate and post graduate students (not engineers… They tend to suffer from a different problem).

    There is a linguistic characteristic that (and you can get mad all you want but it’s just a fact) started with women in the late 80s and by the late 2000s crept into the academic “lingua Franca” of normative speaking in general.

    It’s not the acceptance of a generational colloquialism such as “my bad“ that rings so painfully in the ear… no it is something far more subtle – something far more insidious.

    The moment I note it in a speakers presentation I loose focus and even interest. It a linguistic characteristic that betokens a total lack of self-confidence and authority in yourself and your subject.

    Have you guessed it?

    Think about it… have you guessed it?

    When you read “have you guessed it?” In your mind or allowed you ended that interrogative in an upward inflection. That is normal. That is appropriate. You naturally and always end an interrogative even an interrogative statement with an upward inflection in the voice. You probably read an interrogative or interrogative statement with an upward inflection subconsciously. It’s intuitive and normative.

    But something went wrong a couple decades ago… something with seriously seriously wrong with nominative linguistic characteristics.

    Go listen generally to formal and informal speaking, particularly in millennials but this aberrant characteristic is creeping in into older speakers and demonstrated normative two younger speakers.

    Do you hear it?

    The interrogative upward inflection now ends most sentences and statements. There is nothing more off putting, nothing that shakes the opinion in the self-confidence or authority of a speaker then when he or she continuously ends declarative statements with an upward inflection.

    The mechanics are important but secondary to the presenters confidence in themselves and their material. Ending declarative statements with upward inflections shatters that perception.

    I challenge you to go listen for yourself.

    • Hi Wes,

      A few things to consider.

      First, language evolves. There’s a reason you don’t go home at night and read your Canterbury Tales in good old Middle English. English contractions, for instance, are in fact a fairly recent linguistic development — do you object to their use as well?

      Second, although you may not have intended it as such, it is comes across as fairly sexist to (a) ascribe so-called “uptalk” to women and (b) treat speakers exhibiting this vocal pattern (largely women, from your account) with such vehement dismissal and disdain. A quick wikipedia search (e.g. https://en.wikipedia.org/wiki/High_rising_terminal) reveals a few facts which might be of interest. First, despite your perception of “uptalk” as signaling self-doubt, it interestingly appears that *leaders* are often more likely to use this linguistic device than their subordinates. Second, even if this vocal pattern is indeed driven by women, this should decidedly not be viewed as a negative. In fact, linguists generally accept that women are predominantly responsible for leading linguistic evolution (see https://en.wikipedia.org/wiki/Gender_paradox#Changes_from_below). You may well have women to thank for the modern-day “nominative linguistic characteristics” you hold very dear.

      I certainly cannot prescribe to you which vocal patterns you should enjoy, no more than you can instruct me in which music I should like. What I can ask, though, is that you judge speakers based on the science they have performed and the story they tell, not on their gender or generation.

      • Tom

        I would hope that anyone who has explored English literature, even if that exploration was limited to an undergraduate survey course, recognizes Chaucer’s importance as both establishing a poetic lyricism in Middle English as well as the politically galvanizing move to write the Canterbury Tales in English and not in French – a watershed moment in 14th century post Norman England.

        Yes language evolves. You only have to go back two centuries to see how American English has changed. The span of change from Chaucer’s 14th century Middle English to the English of today is immense. But this is certainly not a condition unique to the English language. A case in point is the Old Norse of the Poetic Edda and Codex Regius (arguably early 13th century in origin) is markedly different from modern Icelandic or Norwegian. I doubt that many 14th century European languages would be anything more than recognizable to a modern ear.

        That was not the issue in my post. The issue is the intrusion into academic (and general) language of a distracting linguistic quirk.

        I found your response to my post both condescending and meretricious. I for one do not know how you go from “off putting” and “shakes the opinion in the self confidence and authority of the speaker” and infer ‘vehement dismissal and disdain.’ Nor can I understand how when most empirical studies (Including the source references in two links in your response) traces the origin of [uptalk] to adolescent and post adolescent women expressing the post preppy/pre-valley girl linguistic mannerisms originating on the West Coast of United States*, its linguistic vector as a vocal crutch particular but not exclusive to adolescent female language skills in conversation and public speaking, and the linguistic vector growth in millennials of both sexes but particularly female millennials – that somehow the anecdotal and experiential anecdote of my post was ‘sexist’ when I clearly expressed the same opinion. I can only conclude Tom, that you read my post and were triggered by reading or skimming it with a jaundiced eye shaped by an ideological adherence to the pernicious and pervasive intersectional feminist orthodoxy so prominent in the humanities departments of the Academy.

        The only thing to consider here Tom is anything that distracts the listener detracts from the message and using vocal affectations to include but not limited to uptalk is a distraction.

        I expect excellence in my students. Excellence and their scholarship, and in their ability to competently and confidently interpret that scholarship (including verbally) to a wider audience. I certainly do not need to be asked by you to look past their gender or generation. It is axiomatic in me and insulting from you.

        William LaBov’s work in dialectology and sociolinguistics prove many aspects of language acquisition and how language changes over time. He also recognizes that some regional and sub-cultural group dialects and linguistic characteristics may carry negative connotations within standard [academic] English. So yes Tom, language does evolve within the normative standard but can also devolve from the normative standard. Using your Ideological coherence – well I have women to thank for this too?

        I must exhibit to you one of the (many) flaws of approaching an argument from the current intersectional feminist orthodoxy (apart from the auto-reflexive attack of or claim of sexism and perfunctory bleating of and incessant virtue signaling) is the fact that acknowledging and celebrating the contributions of women as something exceptional instead of something that is expected – devalues the cause and perpetuates the mythos and condition that women must be treated specially, that they require constant reassurances of their value and contributions as equal instead of excepting and expecting that women are equal. This orthodoxy is what turns the historiography of the contribution of women into a tedious and self defeating hagiography.

        Any argument that accepts vocal affectations in academic speech as an evolution is arguing on tenuous if not intellectually disingenuous ground. Proper and non-distracting verbal communication is the hallmark of erudition and a standard that should be enforced to ensure nothing stands in the way of effectively communicating the science (subject).

        *(some studies effectively argued that the true antecedent rests in the southern regional dialect – specifically “the southern belle” affectation.)

        • Hi Wes,

          This will be my final post here, as I suspect you are simply trolling. Even if you are not, you are clearly not worth further engagement, nor deserving of a platform from which to further disparage and distract from the excellent article above. I do appreciate your latest post, though — for any third party readers of these comments, your belligerent and hyperbolic tirade has clearly validated my initial reply above.

          To any such third-party readers of this website (in particular students) — please do not be discouraged by Wes’ sentiments and others like them. Astronomy (and academia in general) certainly has its fair share of problems accepting and valuing people, perspectives, and behaviors falling beyond the “Academy”’s (to borrow a phrase) cis-white-upperclass-male norm. But we can strive to make it better. In particular, we can start by highlighting and confronting problematic and discriminatory behavior when we see it.


          • Tom,

            I appreciate the exchange. It is a shame that restrictive cognitive dissonance and a gated logical cohesion of coherence only allows you to see and interpret my part of the exchange as a trolling disparaging belligerent discriminatory hyperbolic sexist tirade.

            The one salient point of departure for me is that I would never advocate that you be denied a platform to express and share your thoughts and opinions. The best way to grow is to explore the diversity of opinions and the best way to root out faults in critical thinking with people who may share your narrow interpretive intellectual orthodoxy is to provide the widest possible stage and let the sun shine.

            I wish you luck,


  3. Outstandingly useful advice. Thank you for writing this up!

    • Tom,

      I appreciate the exchange. It is a shame that restrictive cognitive dissonance and a gated logical cohesion of coherence only allows you to see and interpret my part of the exchange as a trolling disparaging belligerent discriminatory hyperbolic sexist tirade.

      The one salient point of departure for me is that I would never advocate that you be denied a platform to express and share your thoughts and opinions. The best way to grow is to explore the diversity of opinions and the best way to root out faults in critical thinking with people who may share your narrow interpretive intellectual orthodoxy is to provide the widest possible stage and let the sun shine.

      I wish you luck,



Leave a Reply