Small Multiples for Qualitative Data
A small multiple is a series of miniature, similar graphs displayed together for easy comparison. The term was popularized by Edward Tufte in reference to the display of quantitative information.
However, small multiples can also be used to visualize qualitative data, allowing users to quickly perceive differences in objects or changes over time. I’ll explore two popular forms of visualization in qualitative research: the word cloud and the social network diagram, demonstrating how these methods can benefit from a small multiple approach.
Word Clouds / Word Storms
Word cloud creators, like Wordle and Tagxedo, generate visualizations from text, giving frequently used words greater size and prominence in the swarm. While word clouds are tools for generating high-level summaries of single documents, word storms* are useful for creating comparisons between multiple documents. Presented together, word storms compose a powerful visualization. This display might be used to demonstrate differences or similarities in how disparate groups discuss a given topic or how different news outlets present the same news story.
Social Network Diagram
Social network diagrams are often presented in a pre/post format to show how an intervention strengthened and expanded collaborative ties. The concept of small multiples takes the display to the next level, allowing users to discern differences over time. Here, I use MIT’s Immersion tool** to visualize how people are connected through emails. The small multiples below use metadata from 9 years of my personal emails to visualize my social network as I graduate college, join the workforce, enter a career-field, plow through graduate school, and move across the country.*** Displaying the social network diagrams together in a small multiple formation allows viewers to consider each year individually, while making comparisons.
In conclusion, small multiples are effective for presenting qualitative data as well as quantitative.
* Faculty with the University of Edinburgh are publishing exciting work on word clouds. To read more about their methods, visit: http://groups.inf.ed.ac.uk/cup/wordstorm/wordstorm.html
** Check out a video on MIT’s Immersion program here: http://vimeo.com/69464265
*** Each node represents a person in my “email life” and each tie denotes a piece of communication. The larger the node, the greater the number of emails.