Design & Design Principles
5. Images, Graphs, & Colors: A Picture is Worth a Thousand Words
Jump to Section: Resolution | Scanning Pictures | Graphs & Charts | Colors
It has been proven that visual aids (charts, graphs, diagrams, images, etc.) increase the effectiveness of research posters
Be sure to use the right visual aids to have the right effect! An attractive poster will catch a reader's eye at first glance and draw them in to read your poster or listen to your presentation. Whenever possible use an image or graphic to portray information rather than a paragraph or text.
A few things to consider when inserting images and graphs:
- Respect the fact that the viewer has a limited amount of time to spend looking at posters by making sure the time spent at your poster is effective and informative. Communicating a concept visually will help you to communicate the message faster, and will help the reader retain the information.
- Be sure to include a brief caption for your figures, and explicitly refer to the figure in the text.
- Charts and graphs must include a title and labels for each axis in order to be meaningful. Failure to include these will require you to constantly explain what the chart or graph means.
- Consider using QR codes to link to supplemental materials1. They are a great way to get your viewer more information. You can use it to include your contact information, a link to a webpage, or even an online video that further explains your research!
When looking to add images to a poster, many people go straight to the internet. A word of caution however if you are going to use an image you got using a search engine such as Google. Most web images have 72 dots per inch (dpi) of resolution and printing at that resolution looks absolutely terrible. Choosing to put a low resolution graphic on your poster shows a lack of care and attention to detail, and can detract from the quality of your research.
Try not to enlarge a graphic once it is brought into PowerPoint as this will decrease the resolution and result in a lower quality image. Try to have the resolution of all of the images on your poster be at least 150 dpi, but no more than 300 dpi. If you are unsure about the quality of an image, visit our link on checking how your poster will look when printed. If you are taking photographs, be sure to use a high quality digital camera. Take plenty of pictures from different angles and with varying lighting to ensure that at least one has crisp detail, good composition, non-distracting background, etc.
If you plan on scanning pictures that will be included in your poster, we recommend saving them in .JPG format. PowerPoint can import most JPG files easily. As far as what resolution you should scan your file at, 300 dpi is usually a good starting point.
To get an idea of how well a scanned image will print, open the file and zoom in on it until the image fills your entire screen. This should give you a general idea of how well it will print when it's enlarged. If it looks pixelated and jaggy the resolution is probably too low and the image should be rescanned at a higher resolution.
On the flip side, if you use a resolution that is too high you may end up creating a graphic (and therefore PowerPoint file) with an unnecessarily large file size that becomes hard to transmit and open. There is indeed a point of diminishing return with image resolution. We would suggest that anything over 300 dpi is unnecessary.
Borders & Lines
When adding an image to you poster we recommend that you add a contrasting border to set it apart from the background. This will also give the image a clean “framed” look. Choose a line color that is complimentary to both your poster and the image. Now is not the time to get crazy with your colors by picking something bold and distracting. Be sure to avoid using lines with a thickness less than 2 points as they won't show up on your poster because they are so thin!
Effective Graphs & Charts
Be sure to give your graphs and charts clear and concise titles that give your reader direction.
Interpreting legends is sometimes very difficult, and you should do anything in your power to make your graphs clearly understood by the viewer. Don’t just take you graph “as is” from the program you have created it in. Add ‘arrows’ or ‘callouts’ to directly label various elements. Giving the reader additional visual cues (e.g. below) will help the reader better understand the information on the graph without having to get into nitty gritty of the data they contain.
Avoid using labels on your graphs that are aligned vertically. It’s not comfortable or natural to have to tilt you head to the side to read something, so don’t make your readers do this. The less painful the interaction with your poster is, the better.
Do not use acronyms or abbreviations unless they are widely used within your field of study. If you do use abbreviations, be sure to first write out the full word or phrase followed by the abbreviated term in parenthesis. Afterwards, you can use the abbreviation alone. This will provide a reference to readers who may not be familiar with the abbreviation.
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.
- 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.
- 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.
- Legend: it's taking up space that would be better spent on the graph.
- 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. http://www.ncsu.edu/project/posters, visited 8/29/2005
Avoid Using Pattern Fills in Charts and Graphs
Avoid using a pattern fills when creating charts in Excel. 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).
Don’t try to get fancy and make your graphs 3-D. As seen above, when you add depth to a chart it is harder to get an accurate reading on the Y-Axis.
If you absolutely must use a pattern, there is a workaround you can apply
- Once the chart is placed on your poster in the right position and at the correct size, click the left mouse button on the chart so that it is selected.
- Next press Ctrl + X (to cut). This process will put your chart onto the PowerPoint clipboard.
- Then press Ctrl + Alt+ V for Paste Special. When the dialog box comes up pick the option Picture (PNG) and press ok. This will convert your Excel chart into a graphic. (WARNING: You will not be able to edit your chart once it's converted to an object.)
Once this is done, position your chart in the poster. After you have done these steps the stripes in your chart will blow up proportionality as seen in Figure A.
The colors used in a poster can have a very positive, or conversely, a very negative effect on your presentation. Take a moment to look over each of the sections below for a quick crash course on color use.
Choosing Your Colors
We have provided a couple of guidelines for choosing a color palette for your poster. Make sure to keep the number of colors to a minimum.
1. Use colors from your school or organizations logo.
2. Choose an image or graph from your poster.
3. Use an online resource like http://www.colourlovers.com/palettes/
Create a Pattern
No we’re not suggesting you use a plaid background or fill your boxes with polka dots; we’re talking about the flow of colors on your poster.
When using different colors for your text, headlines, etc. be sure to use the colors in the same way throughout your poster. If you use blue for the heading of one section, make sure to use blue for all of the other headings as well. The goal is to cause recognition and aide in the navigation of your poster, not to introduce chaos.
Consider the Color Blind
Sometimes the colors in a given image are unavoidable, but when choosing the colors you use in charts and graphs keep in mind that not everyone can see the same variations in color. There are two simple things to keep in mind when considering visibility your viewers who may have color deficiencies. You can learn more about designing with partial sight and color deficiency in mind at usability.gov.
- Increase the contrast of the colors that will be used next to each other. For example yellow on red would be a bad color combination, but if you use a light yellow and a deep burgundy it will be much easier to see the difference.
- Pick colors from opposite sides of the color wheel. The further away the colors are from each other on the color wheel, the easier it is to tell them apart.
Dress To Impress (And to Match!)
You probably don’t give too much thought to your outfit for the day of your poster presentation beyond looking professional, but this can be another great opportunity to present both yourself and your research poster well. Much like deciding on the colors for you poster by looking at a logo, picture, or color palette, you can use the colors in your poster help you match your poster.
Going the extra mile to match your clothes to your poster presents a unifying visual and shows that you have literally thought of everything!2