Images in computer-based presentations

Copying and pasting images into computer presentation programs is unwise. This is because copied images are translated into a large-size, uncompressed image format that is native to the operating system, no matter what kind of file the original image was.  For example, a 32 kB compressed JPEG image copied and pasted can become a 1119 kB uncompressed BMP image in Powerpoint. This greatly bloats the size of the ultimate Powerpoint file, and enormous files can cause presentation problems. In contrast, if the image is imported using the usual import button or menu item, the image remains in its original JPEG format and the ultimate Powerpoint file size remains small. The bigger and more complex the presentation file, the more likely there will be a problem. Keep things as simple and as small as possible.

Example: in a recent meeting I saw presentations that took several minutes to load, delaying the start of the talk and making everyone worried that the computer had crashed.  These Powerpoint presentations had file sizes up to 400 MB for 15 minute talks, ten to forty times the size that they needed to be.

Key Elements in Preparing and Presenting a Talk

Delivering a talk is not the same as writing a paper and should not be treated as such. Remembering this one point will do wonders for any presentation. The following suggestions will help refine and enhance your communications skills.

Introduce, Inform, Conclude

In most introductory communication courses the teacher will instruct the class, "Tell them what you are going to tell them (introduction), tell them (body), and then tell them what you told them (conclusion)."

A typical introduction uses a grabber, such as a rhetorical question, a statistic, or a story to grab the audience's attention. You should then clearly state in ONE sentence the thesis of the talk (e.g., I am here today to demonstrate that the wheel is most effective when patterned after a circle rather a square). Finally, in ONE sentence, state what the talk will cover. (For example, "This presentation will review wheel design and our wheel construction method, and will demonstrate why the circular design rolls better than the square design.")

In the body of the talk, present your information in the same order, using transition statements between each point to review the point just completed and introduce the next. The body should include basic information about your research method and your results. A talk is not being peer reviewed nor is it likely to be the basis for reproducing your research. (How many abstracts did you cite in your last publication?) Therefore, unless your talk is about a new method or a study of a method (methodology), a one- or two- sentence summary is enough. The body of the talk should be delegated to presenting your findings, which should be the points you listed in your introduction.

The conclusion should repeat the main thesis statement and the primary points covered, then link back to the introduction, perhaps by answering the rhetorical question or finishing the story.

Keep It Simple

Narrow the talk to between two and four key points. Most studies conclude that people cannot mentally organize more than that during a presentation. A common mistake in scientific talks is to put several years of research detail into a 20-minute talk. It cannot be done coherently. Details should be left to written materials. Audience members who want more detail will contact you later.

Talk to Me

Your audience cannot go back and review what you said or stop and consult a dictionary for words that are unfamiliar. Use short words whenever possible, decipher acronyms clearly and slowly, and avoid jargon even when speaking to peers. Moreover, creating new terms should be left to manuscripts and should only be done when no other combination of terms is practical. Geology is an incredibly diverse discipline, and it is a mistake to assume that everyone who attends your talk has enough background to understand the jargon and the acronyms specific to your subfield.

Body Language Matters

Much of an audience's response to you and your talk has nothing to do with what you say, but with how you say it. To ensure that the audience stays focused on what you are saying:

Watch the Clock

Practice a talk more than once, and time it, before stepping in front of a lectern. Then, watch the clock while speaking. Regardless of how interesting your topic may be, going past your allotted time is rude to your audience and to other speakers. Remember that it is the job of the session chair to stop you if you go over time. A typical maximum rate of speech is about 100 words per minute, so a 15-minute talk should include no more than 1500 words.

Remember Murphy's Law

Be prepared for equipment to fail:

Computers and Presentation Software

Computing hardware and software can allow speakers to create highly versatile digital presentations. This can be a boon or a bane. On one hand, it allows for colorful, dynamic presentations that can be edited up to the last minute. On the other hand, such presentations are subject to two types of problems.

  1. Equipment or software failure. If the computer decides not to work for whatever reason, you need some kind of backup (see Murphy's Law above).  Note that complicated presentations are much more likely to fail than simple ones.
  2. Presentation design flaws. Because presentation software often includes wild color schemes, complicated canned templates, animation and transition effects, and sound effects, you have the opportunity to be creative. Unfortunately, presentation software generally has few or no guidelines on what works: what color combinations are easy on the eyes, what types of text or graphic elements reproduce well on screen, and how to arrange things to make your real points.
  3. In addition, fancy background patterns, transition effects, and other such rubbish will probably just distract your audience, and make it harder for them to extract your points and information from the background of colors, patterns, and effects.

Use the following guidelines when designing your next digital presentation.

Preparing Slides (any projected image) Using a Computer

General Rules

Use of Color

Text Slides

Maps and Figure Slides

Summary

Source of the original material:

 

Cockerill, K and Wawrzyniec, T.F., 2001a, When presentations go bad: a commentary - Part I: GSA Today, v. 11, no. 2, p. 12-13.

Cockerill, K and Wawrzyniec, T.F., 2001b, When presentations go bad: a commentary - Part II: GSA Today, v. 11, no. 3, p. 24-25.

 
Contact:

Geology Department Chair

Geology Department

Union College

Schenectady, NY  12308

U.S.A.

Phone: 518-388-6770

FAX: 518-388-6417