Effective Graphs On Your Scientific Poster
Having short, informative graph titles helps to lead the viewer more effortlessly through your poster.
Interpreting legends is sometimes very difficult, and you should do anything in your power to make your graphs easy on the brain. Most graphing applications automatically give your graph a basic legend that you should replace with 'arrows' or 'callouts' so that you can directly label the different elements instead. Consider using miniature illustrations to your graphs (e.g., as to right) if at all possible. These visual additions help attract and inform viewers much more effectively than text alone.
Y-axis labels aligned horizontally are much, much easier to read, and should be used whenever space allows.
Acronyms and other shorthands for genotypes, strains, and the like are great when talking to yourself but are terrible for communicating with others. On your graphs, use "english" and then add the strain in parenthesis (e.g., "Control genotype (Col-0)").
Example
Looking at the graphs below, there is a significant difference in the way the information is being displayed. With the original graph to the left, there's a lot of ink that doesn't convey information relevant to the main point being made. The graph to the right is much easier to understand after applying the following changes.
1) Grey background: not only does it provide absolutely no information, it's also unsightly. After you remove it, you will likely have to darken some of the lines.
2) Grid lines: it's very unlikely that your audience cares about the exact values at each data point - it's the pattern that matters. The grid lines compete with the pattern you're trying to show.
3) Legend: it's taking up space that would be better spent on the graph
4) X-axis: The labeling between tick marks is confusing and the y-axis should cross at zero.
Hess, G.R., K. Tosney, and L. Liegel. 2006. Creating Effective Poster Presentations. URL=http://www.ncsu.edu/project/posters, visited 8/29/2005
Avoid using pattern fills in charts and graphs
When creating charts in Excel that will be in your poster, try to avoid using a pattern fill. Your patterned striped fill may look fine on your screen (Figure A), but when it is blown up to the full size the pattern will shrink and won't be visible (Figure B).
If you absolutely must use a pattern, there is a workaround you can apply. Double-click your chart in PowerPoint, and press Ctrl + A (to select all) then press Ctrl + C (to copy). This process will put your chart onto the PowerPoint clipboard. Once this is done go to the edit menu and select Paste Special. A dialog box will come up with a selection of different options. You'll want to pick the option "Picture" and press ok. This will convert your Excel chart into dumb objects. (WARNING: You will not be able to edit your chart once it's converted to objects.) Once this is done, position your chart in the poster. Right click the chart and select the option "Ungroup". After you have done these steps the stripes in your chart will blow up proportionality as seen in Figure A.
Other Suggestions
If you are using Prism GraphPad, please convert your charts to the WMF format, or break them into dumb objects as described above. Otherwise, erroneous output may occur.
Also avoid displaying two-dimensional data in three-dimensional graphs. 3-D graphs look attractive but obscure true difference among bar heights.
PowerPoint does not allow "wrapping" of text around inserted figures, so if you want this option for a particular section, you need to construct the section as a separate Microsoft Word file (which does allow text to wrap), and then insert this Word file into your PowerPoint poster by the menu command, Insert: Object (select the "create from file" option). When you want to change anything, you merely double-click the section and the Microsoft Word file will be called up, magically, for you to edit.