Are you okay?”

Words like these appeared on the screens of mil­lions of Boston res­i­dents’ and vis­i­tors’ mobile phones on April 15, the day two bombs exploded near the Boston Marathon finish line. The attacks set off a cas­cade of social inter­ac­tions: par­ents called chil­dren, employees texted bosses, hus­bands called wives. Some called to make sure their loved ones were safe; others called for emer­gency help, sup­plies, information.

Each of these inter­ac­tions is now stamped with a time and a loca­tion and stored in the call logs of the phones them­selves. Pro­fessor David Lazer and his team of net­work sci­en­tists want to use these data to better under­stand how we use our social net­works during times of crisis.

The group has devel­oped an app for Android phones users to help them do exactly that. “The cen­tral idea is to see with whom people com­mu­ni­cated during the day of the bombing, and how that com­pared to their reg­ular com­mu­ni­ca­tion, to find out whether people were able to get the infor­ma­tion and resources and emo­tional sup­port they needed,” said Lazer, who holds joint appoint­ments in the Col­lege of Social Sci­ence and the Col­lege of Com­puter and Infor­ma­tion Sci­ence.

Avail­able on the Google Play store, the app will first ask par­tic­i­pants a series of mul­tiple choice ques­tions: Are you single? Do you have chil­dren? Are your par­ents living? It will want to know how you learned about the bomb­ings and when. It will want to know who you were with when you heard the news.

It will then “reach into the phone’s call logs,” as Lazer put it, to iden­tify the most fre­quently con­tacted people in the hours after the bombs went off. It will ask ques­tions about eight of them: how are you con­nected to this person? Why did you reach out them? Did you get what you needed? For each com­pleted survey, the researchers plan to donate three dol­lars to the One Fund Boston, a fund aimed to help those most affected by the attacks.

Net­work sci­en­tists have already done quite a bit of research on mobile phone logs, Lazer said. While this infor­ma­tion can reveal inter­esting patterns—for instance, in periods fol­lowing an emer­gency, the number of calls between people 20 years apart increases—but they can’t pro­vide many con­clu­sions. Common sense would say that those 20-​​year sep­a­ra­tions indi­cate parent-​​child inter­ac­tions. “But you can’t just assert things in sci­ence,” said Lazer.

He hopes the app will add impor­tant con­tex­tual infor­ma­tion to the raw data researchers are already inves­ti­gating. The effort could afford a better under­standing of how infor­ma­tion dif­fuses through society and thereby enable better emer­gency response strate­gies in the future.

Addi­tion­ally, with enough data like this and the lab’s pre­vious app sur­rounding Hur­ri­cane Sandy, they hope we’ll one day be able to use our social inter­ac­tion pat­terns on devices and media to detect and pos­sibly even pre­dict emer­gency situations.