After Orlando and San Bernardino and Paris, there is new urgency to understand the signs that can precede acts of terrorism. And with the Islamic State’s prolific use of social media, terrorism experts and government agencies continually search for clues in posts and Twitter messages that appear to promote the militants’ cause.

A physicist may not seem like an obvious person to study such activity. But for months, Neil Johnson, a physicist at the University of Miami, led a team that created a mathematical model to sift order from the chaotic pro-terrorism online universe.

In a study published Thursday in the journal Science, Dr. Johnson and Miami colleagues searched for pro-Islamic State posts each day from mid-2014 until August 2015, mining mentions of beheadings and blood baths in multiple languages on Vkontakte, a Russia-based social media service that is the largest European equivalent to Facebook. Ultimately, they devised an equation that tries to explain the activity of Islamic State sympathizers online and might, they say, eventually help predict attacks that are about to happen.

Experts who study terrorism and online communication said that the new research was informative, and that they appreciated that the authors would make their data available to other researchers. But they cautioned that the actions of terrorist groups are extremely difficult to anticipate and said more information was needed, especially to substantiate any predictive potential of the team’s equation.