Weave open-source data visualization offers power, flexibility

Computerworld - When two Boston-area organizations rolled out an interactive data visualization website last month, it represented one of the largest public uses yet for the open-source project Weave -- and more are on the way.

Three years in development so far and still in beta, Weave is designed so government agencies, non-profits and corporate users can offer the public an easy-to-use platform for examining information. Want to see the relationship between low household incomes and student reading scores in eastern Mass.? How housing and transportation costs compare with income? Or maybe how obesity rates have changed over time? Load some data to generate a table, scatter plot and map.

In addition to viewing data, mousing over various entries lets you highlight items on multiple visualizations at once: map, map legend, bar chart and scatter plot, for example. Users can also add visualization elements or change data sets, as well as right-click to look up related information on the Web.

The benefits of Weave's interactivity go beyond the visual appeal of selecting an area on a chart and seeing matches highlighted on a map, said consultant James Farnam, project coordinator for the Connecticut Data Collaborative and an early Weave backer. "You're creating subsets of data on the fly," he said. With a single click on a scatter plot, "you can recalculate regression lines and relationships that you're testing."

Users are already working on a set of quality tests within Weave to help find data errors visually, he said.

Weave demo visualization of foreclosures in Lowell, Mass. See the interactive version.

Data visualization tools have long been in the hands of the technically savvy, but Weave aims to help organizations democratize them, creating what project head Georges G. Grinstein calls a Wikipedia of data -- a way for anyone interested in a topic to explore and analyze information about it, instead of leaving the task solely to computer and data specialists.

"Now [you're] engaging the public in a dialog with the data," said Grinstein, director of the University of Massachusetts at Lowell's Institute for Visualization and Perception Research. "That's why Weave is open source and free" -- even though it contains some university-patented technology (the institution agreed to allow it in the software).

Weave is "ridiculously powerful," said Holly St. Clair, data services director at the Metropolitan Area Planning Council. The MAPC is using Weave in its MetroBoston DataCommon site, created jointly with the Boston Foundation's Boston Indicators Project. "The power that we see and the versatility is amazing." In fact, one of the challenges of implementing Weave was how to narrow down its offerings so that end users wouldn't be overwhelmed with options, she said. Story continues on next page.