In this session, we will answer the question:

• HOW are you going to present the data?

The progression of your decisions up to now should help you with the most challenging aspect of planning your data presentation—choosing a medium. There are four basic ways to present data: in writing, orally, through the media, and electronically, or online. For most of this session, we will focus on an approach to sharing information that involves all of these means: the Detailed Chart approach. As we discuss this approach, we will touch on many principles that apply to any type of data presentation. At the end of the session, we will provide an overview of other data presentation methods, supplemented by supporting materials.

The Value of Charts

Often the most effective way to describe, explore, and summarize a set of numbers—even a very large set—is to look at pictures of those numbers. Furthermore, of all methods for analyzing and communicating statistical information, well-designed data graphics, or charts, are usually the simplest and at the same time the most powerful.

— Edward Tufte, Professor Emeritus, Yale University

Charts are data snapshots. They should form the basis for your presentation, clearly leading the viewer through the information and emphasizing key points. One way to think about developing charts for presentation is in a progression from raw data, to data tables, to illustrative charts, complete with labels and contextual writing. Let’s look at an example:

Click here to view some raw data. What do you think?
Imagine staying awake through an entire presentation of raw data
tables.

Now, click here to view the same data (plus a little more) in a table
format. Notice how much easier it is to read. Still, it’s a lot of
information to take in at a glance.

Finally, click here to see how the same data looks in a chart format.
They’re like a breath of fresh air, aren’t they?

But what exactly is it that makes these charts so helpful and easy to understand? Some reasons include the following:

• They are clean, simple, and professional. They don’t use what Tufte refers to as “chartjunk,” such as three-dimensional bars, multiple font types, or excessive writing.
  
  
• They are not overly “technical.” They can be read easily by both professional and lay audiences.
  
  
• They include additional information necessary to understand the data (e.g., the footnotes at the bottom of the charts, which contain important definitions).
  
  
• They are consistent. They do not jump back and forth between formats. For example, the axes always run between 0% and 100%.
  
  
• They are bar charts. Often, bar charts are the most effective and informative way to present data. Other charts (such as line, scatter, and area charts) are also useful in the right conditions. However, pie charts are far less effective in presenting most data, especially when the differences are small, but significant.

The Detailed Chart Approach
There is a way to take the charts shown above to yet another level. Detailed charts include additional information related to a chart, without detracting from its main point or points. The additional information is used to either clarify or supplement something in the chart. The Detailed chart approach is an effective way to present your data to virtually all audiences, allowing you to make multiple points using one display and giving you the most “bang for your buck.”

To describe the detailed chart approach, we will refer to a set of charts based on the Smithtown survey. We will refer to these materials as the Smithtown packet.

The detailed charts in the Smithtown packet actually represent the same data that you reviewed above as raw data printouts, data tables, and finally, charts. Now, in their new format, they serve multiple functions:

• They can be used as an executive summary of the data.
• They can be used to guide an oral presentation.
• They can be easily transformed into Web-based material.

Detailed charts are often presented as a set, which, when taken together, tell a story. When assembling a packet of charts, it is useful to include these components:

• A cover page that describes the enclosed content and provides contact information.
  
  
• A table of contents that provides more detail about the enclosed data.
  
  
• A methods page that briefly describes how the data were collected (e.g., survey procedures).
  
  
• A caveats page that addresses some of the important issues that may arise when looking at the data. For example, validity is an important issue when conducting student surveys—how do we know that the students told the truth? You want to be prepared to address such issues at the start of your presentation. You may also want to address the limitations of the data.
  
  
• Data pages that are grouped in a logical sequence (discussed below)

Data pages typically contain three sections: the chart (discussed above); one or two examples that show how to read the chart; and notes. The purpose of the examples section is to help the audience understand the information contained in the chart by providing them with examples that show how to read the data. The notes section serves to either clarify or highlight particular information. For example:

• On the detailed charts included in the “Alcohol and Drug Use” section of the Smithtown packet, the notes are used to highlight definitions contained in the chart. (See, for example, the chart entitled Current Substance Use for Smithtown High School Students (2000)). Because each chart addresses a large number of variables (about six substances per page), it would be too confusing to try to use the notes section to address issues such as sub-population differences or comparisons.
  
  
• However, on the detailed charts contained in the “Vehicle-Related Risk Behavior” section, the notes are used to address multiple issues. (See, for example, the chart entitled Percent of Smithtown High School Students Who, in the Past 30 Days, Rode With a Driver Who Had Been Using Alcohol or Marijuana (2000)). Rather than creating four separate charts to address differences by gender, differences by grade, comparisons to statewide data, and trends, the notes section addresses each of these.

In an oral presentation, the notes section gives the presenter the option of addressing only selected additional points while allowing the audience to pursue the other information if they so choose. If the packet is used as a written executive summary or is on a Web page, it allows the reader to search for information that is of interest to them. You can also include in the notes section any qualitative data that you might have to illustrative your quantitative findings.

Other Data Presentation Methods
The detailed chart approach can be incorporated into a variety of reporting methods. Click on the links below for brief summaries of each of these methods:

As we mentioned yesterday, the method you select should be driven by audience needs. For example, in the case example above, a community forum was deemed the best “fit” for reaching parents in Smithtown. Table 1 (below) pairs potential audiences with optimal presentation approaches.

Table 1. Selecting the Best Reporting Method for Your Audience

Adapted from Borden, L., DeBord, K., and Snipes, S. Beyond DATA. Department of Family and Consumer Sciences at North Carolina State University. Morris, L. L., Gibson, C. T., and Freeman, M. E. (1987). How to Communicate Evaluation Findings. Newberry Park, CA: Sage.

A Final Note about Language
Writing will, and should, be a part of all your presentations—even if your data is mostly quantitative. Avoid jargon and, whenever possible, use words that conjure up action in your audience’s mind. Make sure that you reread everything that you write, putting yourself in the shoes of your intended audience, or have someone else read what you have written and provide you with detailed feedback. Also, check your writing carefully for consistency, spelling, grammar, dates, and usage, and revise as needed and then read and proof once more.

You’ve made it through the hard part—figuring out what you want to present and how. What’s left are logistics: figuring out how much data to include, who should present the information, and where and when the presentation should take place. We will address these important topics in tomorrow’s course materials.

You have completed today’s presentation. Please proceed to
Activity 3: Choosing a Presentation Method.

References

Cummins, M. (2002). What Now? Effective and Useful Data Presentation. Newton, MA: CSAP's Northeast Center for the Application of Prevention Technologies.

Tufte, E. R. (1983, reprinted in 1992). The Visual Display of Quantitative Information. Cheshire, CT: Graphics Press.