Preparing an Effective Presentation

							                                 Preparing an Effective Presentation
                                          Brad Vander Zanden
                            http://www.cs.utk.edu/~bvz/presentation.html
The following advice for preparing and presenting a talk will help you maximize the impact of your talk on
an audience and ensure that at a minimum they remember the take-away points of your talk. The points
               apply equally to research talks, lectures, and non-technical presentations.
I. Length of Presentation

  A. The average attention span of an adult is 20 minutes.

     1) Implication: you should ensure that the first 20 minutes of
             your talk include any material that you want your audience to
             remember.

     2) Check it out: The next time you attend a talk look around after
            25 minutes and see how many people are doing other things, such
            as doodling, looking at laptops, reading papers, or dozing.

  B. Prolonging Attention Span: You can prolong attention spans by
          periodically giving your audience a rest. This can be done by
          telling a story, giving a demo, or doing something else that
          gives the brain a break. An analogy to what you are doing is
          running hard for a few minutes, taking a break, then running
          hard again. However, just as you will typically not be able to
          run for as long after the break you cannot expect the renewed
          attention span to last as long after the "break". In fact, count
          on having only a couple of minutes.

II. Presentation Content

  A. The 4 Golden Questions: Every research presentation should answer
          the following four questions:

           1. Where are we now?: In other words what is the current state of
              the art before you started your research. Answering the
              question "Where are we now?" will help define for the audience
              the problem your research addresses.

           2. Where are we going?: The answer to this question tells the
              audience what you accomplished. It should be a high-level,
              concise description, not a detailed description. Make sure
              that you answer this question in the first couple minutes of
              your talk. There is an old saying in the newspaper industry that
              you should not bury the headline in the article. The same is
              true of your talk. Do not bury the main results in the middle
              of the talk. Not only might the audience miss them but you might
              be past your audience's 20 minute attention span and they'll
              have already tuned you out.

           3. How did we get there?: Now you can get detailed and describe
              the methods/techniques you used or invented to solve your
              problem.
     4. What is left for the future?: At the end of your talk you should
             clearly state what problems are not addressed by your research
             and are deferred to the future.

           A good talk will provide brief answers to the first three questions
           in the introduction and then hit the "where are we now" and "how
           did we get there" questions in more detail in the rest of the talk.

  B. When you change topics, summarize what you have discussed thus far
         and how that relates to what you are about to discuss next. This
         transition serves three purposes:

            1. It provides a "break" for the audience
     2. It sharpens your presentation by clearly separating topics
            3. It gives listeners who have tuned you out a chance to get back
                         into the talk.

  C. Introduce concrete examples before formal algorithms: Audiences
           grasp algorithms much better if you
           work through a concrete example using the algorithm before presenting
           its formal specification.

  D. Do a demo before discussing a software system in depth: The same
          principle that applies to algorithms applies to software systems.
          Listeners will have a much better idea of what you're talking about
          if you demo your system before explaining implementation decisions.

III. Presentation Format

  A. Fonts

     1. Font Size

             a. For large audiences use a font size of 18 or greater
             b. For small audiences use a font size of 14 or greater

           2. Font Family: Use a sans-serif font like Helvetica. The curls
                     that make serif fonts like Times Roman look so nice in
                     printed reports will cause blurring and eye strain when
                     projected to a large audience.

           3. Font Style/Color

             a. Use a plain font unless you wish to specifically highlight
                    a point

             b. Do not use colors to "spice up" your presentation unless you
                     wish to emphasize a point. The human eye is naturally
                     drawn to changes in color so color can be useful for
                     emphasizing a point. However if you use color indiscriminately
                     then at best you are cluttering your presentation and at
                     worst you are wrecking the listener's concentration.

                      i An example of indiscriminate use of color is to color
                        consecutive bullets differently so that your presentation
                        has "variety".
                    ii. An example of the effective use of color is to use one
                        color for the header topic on the slide and a different
                        color for the bullets on the slide. The change of color
                        will highlight the header and draw the listener's eye
                        to the header, which is the first thing you want the
                        listener to read

B. Slides

        1. The average time spent per slide at talks that I have attended
                  tends to be 1-2 minutes. When preparing a talk for a
                  particular duration you can divide the duration by this
                  average to come up with the approximate number of slides
                  you should use.

        2. Limit the number of bullets per slide to five or fewer. There
                    are two reasons for doing so:

            a. To reduce the clutter on the slide
            b. To handle the limitations of short term memory

                    i Most people can hold 5-7 items in short term memory.
                    ii If you have five bullets on your slide then the majority
                        of your audience can remember the points you're
                        making without re-reading your slide. If you have
                        more than 5 items per slide than some of your audience
                        will be re-reading your slide and not listening
                        to you, thus missing presumably important information.

        3. Make bullets short and snappy. Do not use complete sentences
           unless stating a point that requires precision, such as a
           theorem or definition.

            a. Most people read all the text on a slide before
                    they start paying attention to what you are saying. Hence
                    the more text you have in your bullets the longer it will
                    take for people to start listening to you. If they take
                    too long they might completely lose the thread of thought
                    on that slide which can easily lead to a loss of
                    concentration for your entire talk, especially if you are
                    past the 20 minute threshold.

        4. Color contrasts: A light font color on a dark background is
                   preferable to a dark font color on a light background because
                   the dark background will result in less glare.

            a. Yellow or white on a blue or black background tends to
                    work best. Consider using one of yellow/white for the
                    header and the other for the bullets.

            b. Do not clutter your background with fancy patterns or
                    graphics (e.g., your university's logo--everyone should
                    know where you are from from your first slide): They will
                    only clutter your slides, distract the listener from the main
                    point of the presentation and, in the case of fancy patterns,
                possibly even reduce the readability of your text.

                i. it is okay to use subtle background patterns as long as
                              they are unobtrusive.

        c. When juxtaposing colors, try to use colors from opposite
               sides of the rainbow. Colors that are close to one another
               will appear to blur together and provide poor contrast. For
               example, yellow appears much clearer next to black or blue
               than it does to green. If you've forgotten the rainbow
               an easy way to remember it is as Roy G. Biv (red, orange,
               yellow, green, blue, indigo, violet).

     5. A picture is worth a thousand words: When possible use pictures
                 to emphasize your points rather than text. Pictures can
                 succinctly convey information about processes, algorithms,
                 and software interfaces that could take hundreds of words
                 to convey. You will also use words to explain the pictures
                 so your verbally oriented listeners can focus on your words
                 while your visually oriented listeners can focus on the
                 picture. If you use text only then your visually oriented
                 listeners will be disadvantaged.

        a. Do not use meaningless pictures (e.g., whimsical pictures)
                to make your slides more
                interesting. If you use a picture it should reinforce the
                point you are making on the slide. Random pictures simply
                distract your listener and clutter your slide.

6. Put a header at the top of each slide that succinctly summarizes
         the topic of that slide.

     7. Screen snapshots and program listings: Snapshots and listings are
               next to useless if the listener cannot make out the graphics
               or text.

        a. Code listings

                i. Most code listings I see in talks are unreadable.
                   Most presenters seem to recognize this fact because they
                   usually spend only a few seconds on the slide.

                ii. Usually you care about only a few lines
                    of the listing so show only those few lines and either
                    use a bigger font or use a xerox machine or some other
                    tool to increase the font.

                iii. Usually code listings are ineffective because the
                     listener is unfamiliar with the syntax. Hence the
                     listener spends precious time trying to decipher your
                     syntax while not listening to you.

                iv. Bottom line: Unless the code is an integral part of
                    your results skip it in your talk. If you do include
                    it, then be prepared to spend a somewhat significant
                    amount of time on it so that the listener has a chance
              to understand what you are talking about.

  b. Screen snapshots

           i. Most screen snapshots I see are unreadable because the
              fonts are too small.

           ii. Either use a xerox machine or other tool to enlarge
               the image or edit your code to use bigger fonts before
               taking the snapshots. As an example, a student of mine
               needed to display a snapshot of an event recorder. The
               event recorder displayed a list of events in a 12 point
               font that was easy on a computer user's eye but unreadable
               for an audience. The solution for the talk was to change
               the font to a much larger point size and take a screen
               snapshot. The event recorder displayed many fewer events
               but who cared. The audience members only needed to see
               one event to get the point.

           iii. Do not let your talk become dominated by screen shots.
                A live demo with its dynamicism will make your points
                much more effectively than a series of static snapshots.
                As with the snapshots, try to enlarge the point sizes
                in your demo.

7. Use special effects judiciously: Powerpoint makes it possible
   to fill your presentation with all sorts of "gee whiz" effects.
   You should resist the temptation to use these effects unless
   they actually enhance your presentation.

  a. Example: Having bullets "fly in" is an example of a bad use
         of special effects. Other than distracting your listener
         and breaking his or her concentration, what purpose does it
         serve?

  b. Example: Fading in points right before you make them is
         an example of a bad use of special effects. You can better
         justify the fading in of bullets because it is less
         obtrusive then flying them in and because it prevents the
         listener from reading
         the bullets before you're ready to present them. However, if
         you've limited the number of bullets and kept them short
         and snappy the listener can quickly assimilate the slide and
         should already be listening to you. Fading in the points will
         distract the listener and break his or her concentration.

  c. Example: Fading in information to show what happens as an
         algorithm manipulates a data structure is a good use of
         special effects. For example, coloring the nodes of a graph
         as they are reached in depth first search is an excellent
         way to show how depth first search spreads through a graph.
         In this case, the ability to present new information while
         maintaining the same underlying picture maintains the
         listener's concentration while moving to another slide will
         break the listener's concentration and make it harder for
         the listener to see what has changed.
IV. During the Presentation

  A. You are your own worst critic: Most people are very self-conscious
          when they give a talk. Fortunately, your audience is usually
          concentrating so hard on trying to understand what you're saying
          that they are not noticing the fact that your voice is shaking,
          that you are backtracking in your sentences, or that you are
          saying "uh" a great deal. Hopefully you can relax a bit if you
          know that your audience is not hanging on your every little
          imperfection.

  B. Do not read your slides: Your listeners are perfectly
          capable of reading and can do it more quickly than you can
          recite them. If you've kept your bullets short and snappy you
          won't be tempted to recite them because there will not be anything
          to recite. It is okay to periodically recite a point, such as a
          definition, to drive home a point. Just do not make a habit of it.

  C. Bring a glass of water or some other beverage: Drinking during a
          talk will lubricate your vocal chords and keep you from going hoarse.

  D. Keep the presentation moving: Do not get side tracked by irrelevant
         questions. It is okay to tell a listener that you will be happy
         to discuss the question after the talk but that you need to move on.

          1. If you are stumped by a question do not try to squirm your way
             through it. If you're a good con artist you may be able to
             fake your way through it but you're normally talking to an
             educated audience that will nail you to the wall. It is much
             better to move on to firmer footing and minimize the issue than
             it is to make a big deal out of it and firmly implant it in the
             audience's mind. For example, if you have not heard of a related
             piece of research just admit it and move on.

          2. If questions during a talk disrupt your flow it is ok to ask
             the audience to defer their questions until the end of the
             talk.

  E. Try to keep yourself facing the audience as much as possible. It
           is not necessary to make eye contact but your voice will carry
           better and you'll be more likely to use body language that
           enhances your presentation.