Making and Giving Presentations

During your academic career, you will need to create and deliver many presentations. Many 800-level courses require you to give multiple presentations and, if all goes well, you'll also present talks at some conferences. Academic presentations are generally very different than other types (e.g., business presentations or "CON" talks). This page offers some advice for presenting academic papers, but note that there is no universal agreement on presentation styles—the advice presented here is one perspective.

Content

Selecting Content

Conference presentations involve a fixed amount of time for the speaker to present uninterrupted, followed by a question and answer period. The most important rule for academic presentations is that they must be on time. You should aim to finish within 30 seconds of the designated limit. Exceeding the time limit runs the risk of being cut off by the session chair. Most chairs will provide time alerts during your talk.

It is often said that the purpose of a conference presentation is to serve as an advertisement for the paper. Do not feel pressured to include all of the paper's content in the presentation. Moreover, verbally referring the audience to the paper for more details on a particular topic is a valid technique.

Deciding precisely what content to include in your presentation can be difficult. The first step should be to know your audience. At the top security and privacy conferences, you can expect most people to have a broad background in security and privacy, but it is not safe to assume that people know specific systems or concepts unless they are very well known. For example, it is safe to assume that the audience attending a talk at Oakland (the top security conference) knows about cryptographic hashes, the most common instantiations, and general computer science topics, but it is not safe to assume that the audience is familiar with private information retrieval, the details of the Tor network, or the Cramer-Shoup cryptosystem.

Different people have different techniques for selecting content for the presentation. One highly advanced technique involves creating the presentation before writing the paper, but this is rare. Typically, building a presentation involves extracting content from a paper. One way to do this is as follows:

1. Start by going through the paper from start to finish and make an outline of the key concepts. This outline might be hierarchical, mirroring the structure of the paper's sections and with a short point containing the key idea of each paragraph.
2. Convert the paper outline into a presentation outline.
   1. Identify the key contributions and ideas of the paper, along with prerequisite links between them. It might help to create an intermediate concept / mental map for this step. There may be some in the audience that are familiar with related work in the field and wish to know what makes your work better or different from similar, previous contributions. Be sure to clearly state how your work fits in with existing work (if applicable).
   2. Arrange the key ideas in a linear sequence for the presentation outline.
   3. Eliminate the least important points to reduce the outline to a reasonable size.
3. Use the presentation outline as a blueprint for creating slides.

It is a good idea to have "bonus slides" in your presentation. These slides appear after the conclusion, and are not normally shown at all. However, if somebody asks a question for which relevant information is available in a bonus slide, you can show this slide during the Q&A period. If you find that your presentation is too long, you can quickly "cut" content by moving it to the bonus slide section.

General Structure

Most presentations follow a well-known common structure. Following this structure makes your content easier to understand, and people will generally expect your presentation to do so.

Your first slide should be a title slide that includes the name of the paper, the names of all the authors, and their affiliations. You should emphasize your name if there are multiple authors (e.g., bold or color your name).

After your first slide, you should provide background and motivation for the paper. This is normally followed by an overview of the paper's contributions, which typically appears within the first 20% of the allotted time. If your presentation is long, it is a good idea to follow the contributions with a slide with an overview of the rest of the presentation.

The remainder of the presentation is highly variable and depends on the content of the paper, but it should end with a concluding slide. This slide should include "takeaways" and a short summary of the key points of the talk. It should also include some way to find out more about the paper, such as a link to a website.

Design

Style

Different venues expect different presentation styles. For example, at the top security and privacy conferences (Oakland, CCS, USENIX, PETS, and others), putting references and a bibliography in your slides would be unusual, whereas some cryptography conferences expect you to cite frequently. Before constructing your slides, you should consult with someone familiar with the venue (likely your supervisor) if you do not know the expectations.

Always include slide numbers. These allow people to reference specific slides in their questions.

One key stylistic aspect is the amount of text that you put in your slides. It is almost never appropriate to put so much text in the slides that you are simply reading what is written directly. When using text, you should avoid cluttering the slide and ensure that you are verbally providing more information than is written; short bullet points (often incomplete sentences) work best.

A more advanced technique is to create presentations with little or no text. This style requires that you remember what to say for each associated image or diagram. The benefit is that it tends to produce more engaging presentations. If you have not given many presentations before, it is a good idea to start with more text on the slides in order to avoid the additional mental load of improvisation.

If your content includes math that is not a core contribution of the work, then it is a good idea to avoid it if possible. For example, cryptographic protocols and operations can be represented with diagrams instead of equations. This technique also helps to improve engagement, since it simplifies the material and makes the presentation more accessible, while still delivering the idea and importance of the paper's contributions. People who are interested in the details can always refer to the paper. In contrast, if the mathematical details are a key contribution of the paper or if you are presenting at a math-focused venue (e.g., a cryptography conference), then including the mathematical details is crucial.

Do not include animations in your presentation unless they have some meaning related to the content.

Striking the correct balance between rehearsed and improvised speech can be challenging. Rehearsing too much (in the extreme example, reading a script or cue cards) can make your presentation seem forced or insincere. Rehearsing too little runs the risk of awkward transitions, timing problems, or incorrect details. Stage frieght can also throw off the calibration for new presenters. One useful trick is to give a practice talk of the whole presentation a couple of times, while rehearsing the first few slides far more frequently. Memorizing precisely what to say during the first moments of the presentation can help to overcome stage frieght so that transitioning into improvisation is easier. If you are a non-native English speaker, rehearsing more than a few times may be helpful.

Tools

There are many available tools for creating presentations. A few of them are listed here:

• LaTeX with Beamer. This is probably the most common choice at conferences frequented by CrySP members. Advantages include uniformity (eliminating design as a distraction), easily constructed equations, and good compatibility with version control systems. Disadvantages include uniformity (boring designs) and slow development for complex graphics. If you are using Beamer with the default Madrid theme, you should disable the useless buttons.
• PowerPoint. A good choice for Windows users. Both offline and online versions (with fewer features) are available. Advantages include quick development for highly graphical presentations and low learning curves. Disadvantages include non-free authorship tools, Windows requirements, and viewer requirements.
• LibreOffice Impress. This tool is roughly equivalent to an older version of PowerPoint. It can create presentations much faster than Beamer if you don't have many equations. However, LibreOffice is known to be very buggy. Make frequent backups of your presentation and save all images before importing them into the presentation (LibreOffice is known to corrupt images over time, so you might have to re-import some).
• Inkscape. It is possible to use Inkscape, which is normally used for creating vector graphics, to make presentations with several different plugins and scripts. Advantages include precise graphical control and vector-based output. Disadvantages include awkward multi-slide editing (depending on the plugin) and difficult creation of auto-scaling bulleted text.
• Google Slides. This is a relatively simplistic online slide editor. It is free, quick, and can be used offline. However, it has limited capabilities.
• HTML5-based editors and libraries (e.g., strut.io, reveal.js, impress.js, deck.js, Shower). There are many presentation frameworks and editors of this variety. They are generally not a good choice for academic presentations because they lack good editors, include dramatic transition effects (e.g., many try to mimic Prezi, which is a bad design choice for academic venues), or are highly restrictive.

No matter which tool you choose, you should always ensure that your final presentation (possibly with some graceful degradation) is available as a PDF. You cannot rely on an Internet connection being available at conference venues. Additionally, your computer may not work with the venue's equipment. Having a PDF available greatly improves your resilience to technical problems due to its portability.

Arrive at your presentation venue well before your scheduled talk (e.g., in a preceding break) with your laptop to test the equipment. Many session chairs will actually insist that you do this. Be sure to bring a backup of your slides in PDF format on a USB drive.

Your presentation should work on 4:3 projectors. While some venues support 16:9 slides, the physical screen is usually 4:3, so using 16:9 slides simply wastes space. Some projectors still only support VGA, so make sure you have a working and tested VGA adapter. The majority of projectors support only HDMI. Projectors that support something other than VGA or HDMI are exceedingly rare.

When presenting a PDF file, consider using pdfpc. This application provides slide previews, a clock, and other details on your laptop while the full slides appear on the projector.

Tips

In addition to the suggestions above, this section includes some general tips.

Content / design tips:

• Put page numbers on slides. This is very important, because it allows people to reference specific slides when asking questions. Most presentation software includes a method to jump to a specific slide number (e.g., typing the number and pressing Enter), which allows you to avoid scrolling through the entire presentation while the questioner waits for you.
• Do not include the date, sponsorship logos, or addresses on the title slide. Most of the time, you should also avoid including the name of the venue unless you intend to make the slides available elsewhere.
• If you include an overview or outline slide:
  • Avoid technical terms that will be introduced later,
  • Keep the slide short and understandable,
  • Do not provide a "generic" outline (an outline that says "Background, Design, Implementation, Evaluation, Conclusion" provides no information), and
  • Consider incorporating the current "section" of the talk into your slide design, or occasionally returning to your outline slide with the next section highlighted (or the completed sections faded out). This can be particularly important if your talk involves a lot of results, constructions, or topics that build upon each other in a non-obvious way (e.g., cryptographic protocols with multiple layers of obscure primitives).
• Use large fonts. People in the last row should be able to read the text on your slides. Do not use sizes smaller than 20 points.
• Avoid crowding your slides with text. Any more than 12 lines is almost certainly too many.
• Every slide needs a message, and this message should be clear. This is especially important for slides with graphs; it should be clear what the audience should learn from any graphs you show. Be sure to explain graphs thoroughly, and point out any potential sources of confusion (e.g., log scales).
• Do not include filler slides. If you don't expect your audience to read a slide, do not include it.
  • One rare exception to this rule is when it is necessary to expose a higher level of complexity available in the paper. For example, if you are presenting a survey paper that includes a comparative table, it might be appropriate to include a simplified table in your slides, and then follow with an image of the complete table as it appears in the paper. In this exceptional case, it is important to verbally state the purpose of this slide and that you don't expect the audience to read it. This is also a good opportunity to make a joke.
• Do not use 3D if there is no need.
• Use a consistent emphasis style (e.g., bolding or coloration).
• When choosing a color scheme, keep common forms of color blindness in mind (quick answer: if contrasting two things using color is important, consider yellow and dark blue).
• Spell check your slides and check your grammar.
• If you use gendered names or images as examples, use the correct pronouns (e.g., "Alice" is not typically referred to as "he"). Alternatively, just avoid gendered names.
• Do not use sexually provocative images or jokes in academic presentations, even if they are relevant to the subject matter (extremely rare).
• Avoid overuse of unrelated or complex metaphors (e.g., representing crypto primitives as genomes). If the metaphor is more complicated than the original concept or outside of the audience's area of expertise then it does not serve the purpose of simplifying the concept. Overuse of metaphors can similarly distract the audience from the key concepts in the talk. Strive to make your talk relevant to the field and straightforward.
• Do not end with a slide with no useful information. A slide that simply says "thank you" or "question?" is not useful. The audience will often spend a long time staring at the final slide, since it will be displayed during questions. This attention makes the final slide an excellent place to provide take-home messages. Note that you can include a "thank you" message on your final slide to reinforce that the presentation is over, as long as it is accompanied by the take-home messages.

Presentation tips:

• Be aware of your remaining time. Your primary objective should be to avoid delaying the program; delivering your content is secondary.
  • Use presentation software, like pdfpc, PowerPoint, or Impress, that display a clock for you in an unobtrusive way.
  • Avoid visibly glancing at your watch or at a clock on a side wall. The audience's attention will be drawn to the flow of time and this may cause them to lose focus.
• If you rehearse your talk, make sure that the rehearsed timings are not saved. Some software, like PowerPoint, will automatically advance your slides based on your previously rehearsed times, causing early confusion. Keep this common mistake in mind so that you know what to do if it happens to you (stop the presentation, delete the timings, and resume from the most recent slide).
• Most session chairs will introduce you. Some will also read the title of your paper. Avoid repeating the information that was just said; a simple technique is to thank them for the introduction and immediately transition to the next slide.
• Face your audience while speaking. Do not spend too much time staring at your laptop or the presentation screen.
• Use feedback from your audience. If people look confused or sleepy, you can adjust your verbal delivery.
• When you are asked a non-clarification question that is quiet, unclear, or difficult to answer, repeat it first. In venues without microphones for the questioners, this is necessary so that the whole audience can hear the question. It also helps to confirm that you understood the question correctly, and it gives you some additional time to mentally prepare an answer.
  • Note that when you repeat a question to some people, they will start over again or ask a difficult question instead of confirming that you summarized correctly. If this happens, don't repeat their question a second time.
• After spending some time (at least one question-answer round) with a question, you can always say "let's take this offline" to mean that you'll discuss more with the person after the session. You should request this whenever the Q&A session is being stalled by a long discussion, particularly if the question makes no sense to you or if the questioner clearly doesn't understand the material.
  • If a questioner asks to take the discussion offline, agree immediately; don't spend more time trying to clarify what you've said.
• Do not read directly off of the slides.
• Avoid mumbling.
• Speak into the microphone. Most conference microphones are fixed and highly directional, so even turning your head to look at your slides can cause distracting volume changes. If there is a fixed microphone, don't walk away from it to pace or point at something. If you are given a hand-held microphone, remember that it doesn't work unless you hold it pointing toward your mouth (this is easy to forget, especially if you are inexperienced with presenting or you use many hand gestures when speaking).
• If you use software like f.lux or Redshift, disable it before presenting to avoid having orange slides.
• Watch your hands. Do not put your hands in your pockets. Using a remote control with a laser pointer can help, because holding something gives your hands something to do.
• Avoid distracting movement such as pacing or swaying.
• Be polite. If somebody asks a question in a rude manner (a rare event), answer politely; if your response is polite, the talk afterwards will focus on the negativity of the question, and people will empathize with you for having to deal with it.
• People will often suggest or point out weaknesses of your work during the Q&A session. If the weakness is legitimate and it was not covered in your slides (and you didn't predict it in your bonus slides), don't be afraid to readily admit to the shortcoming. No paper is perfect and devoid of drawbacks and trade-offs.
• End your talk definitively (e.g., "This concludes my talk. Thank you for your attention.") rather than trailing off (e.g., "so, uh, yeah, that's about it"). This is an applause cue for the audience and a cue for the session chair to initiate the question period, avoiding a period of awkward silence while people are unsure if you're going to say something else.

Providing Feedback

Providing constructive feedback for people helps them to improve their future presentations. This mostly applies to practice talks, but also if people request feedback for their conference talks. During practice talks, take notes to bring up during the discussion period or privately.

Providing feedback is important and valuable even if you are unfamiliar with the content or the venue. The most constructive form of feedback for practice talks tends to be descriptive feedback (conveying your experiences as an audience member) with optional prescriptive feedback (suggestions for change). In other words, the most useful feedback can be written in the following format:

"[On slide <slide number>], <description of experience/event>. [You might consider <change>]."

For example:

• "I didn't understand how the concepts in the last section were related."
• "On slide 18, the axes in the graph were unlabeled."
• "On slide 5, the wording made me think that revealing the secret was undesirable, but it was actually the goal of your system. You might consider rephrasing the second bullet using words with positive connotations."

Descriptive feedback is useful because it allows the presenter to evaluate the effects of the presentation and devise a modification if necessary. Since the presenter is presumably intimately familiar with the subject matter, past feedback, and the history of the presentation, they are in the best position to decide how to proceed.

Make a note of all feedback that you receive when giving practice talks. When processing descriptive feedback, follow these steps:

1. Determine if it represents an issue (e.g., if somebody reported that they were expecting an overview slide and you know that overview slides are not conventional for the target venue, no action is needed).
2. Identify the source of the experience (e.g., if somebody didn't understand a step of an algorithm, they might be missing prerequisite knowledge for the operations in that step). If necessary, discuss with the person to collaboratively discover the source.
3. Modify the presentation to eliminate the source of the issue (e.g., add slides to introduce missing knowledge, rephrase text to make point more clear, or add a joke during a tedious moment). If you received prescriptive feedback, consider the prescriptions as possible solutions.

(Hint: this method of providing constructive feedback is not limited to preparing presentations.)