Willie Baronet buys cardboard signs from people experiencing homelessness. It’s an ongoing collection the artist and professor has been building since 1993.

In 2014, Baronet launched an IndieGoGo campaign to trek across the country, buying signs from folks living on the streets in 24 cities for an ongoing art project called “We Are All Homeless.”

Two years later, Baronet is still going at it with We Are All Homeless. Earlier this week, the artist attended the opening of an exhibit at the University of Pennsylvania in conjunction with a research project that will be published this fall in the American Journal of Public Health.

The research project, according to Penn’s Center for Public Health, is a “qualitative content analysis” of the messages on cardboard signs. In other words, CPHI researchers will be treating the signs as data and explore how the messaging differs geographically.

“This is the first time anyone has done a research project based on these signs,” Baronet said in a statement. “We were humbled and honored to work with Rosemary and Allison at U. Penn to bring this to fruition.”

Baronet also released a documentary based on We Are All Homeless, titled “Signs of Humanity,” earlier this year.