1. Presenting Data

2. Communication The goal of presenting data is to communicate ideas
Communication is not what you say but what your audience grasps
Know your audience
Be clear and precise
The simpler, the better
Eschew obfuscation

3. Including Numbers Text, table, or graph? Whole numbers
Text = 3 – 4 numbers
Table = < 20
Graph = > 10
Whole numbers
0 – 9 should be written as words
10 and greater should be written as digits
Decimals should have proper number of significant figures

4. Data Summaries
Large amounts of data can be summarized using tables and plots
Focus on data
Tables and graphs should be self-explanatory
Text should mention key points
Final version should agree with text (and vice versa)
Tables
Best used when numerical details are important
Best used when there are few (< 20) values
Also used to show data that cannot be smoothly incorporated in the text or shown as a plot
Plots
Graphs and charts
Graphs have a continuous scale on the x-axis
Charts have a discrete or categorical scale on the x-axis
Used to show trends and relationships

5. Tables Numerical data displayed in rows and columns Clarity
Patterns and exceptions should stand out
Clarity
Each column should have a clear and accurate heading
Reading down is easier than reading across
Make comparisons in columns
Widely spaced columns make comparisons difficult
CAREFUL use of lines, shading, fonts can enhance (or detract!) from readability

6. Tables Simplicity Tips Large tables can be overwhelming
Break them up, if possible
Omit columns that can be easily calculated from others
Try to combine minor or less relevant categories into one larger category
Small fonts are nobody’s friend
Tips
Title or caption goes at the top of the table
Units of measurement in column headings
Within text, refer to table as (Table 1) not “See Table 1”

7. Plots Many different types of plots
Scatter and bar plots most common (for us)
Avoid pie plots
Be aware that details are often lost with plots
Clear, thorough labeling
X-axis independent, Y-axis dependent
Horizontal labeling easiest to read
Keep it simple!
Avoid software/graphic gimmicks
Default values are not always best
Clarity is much more important than attractiveness
3-D plots (especially bar plots) can be difficult to interpret

8. Plots Tips Each figure should have a number, title, and legend
Legend should have enough information so that reader does not have to go to text
Titles and legends go below the figure
Label each axis and provide units
X-axis does not have to start at 0, Y-axis does, unless negative values are included