The autism community is reeling with the news that three autistic children have drowned in just over a week. These tragic deaths highlight the need for more and better research into the issue of autistic wandering, more properly termed “elopement.”

Mikaela Lynch, 9, went missing on Mother’s Day. Her body was found three days later in a creek near her family’s Lake County, California, vacation home. Owen Black, 8, went missing in Perdido, Florida on Friday, May 17. His body was found two days later, in the Gulf of Mexico, a half-mile from where he went missing. On Saturday, May 18, 2-year-old Drew Howell wandered away from his family’s cottage. His family found him almost immediately, but it was too late: he had drowned in a nearby creek, about 100 yards away from the cottage.

When autistic kids wander, it’s not the same as what most people would call “running away.” The word “wandering” also kind of misses the point: autistic wandering isn’t just aimless wandering around; it’s an attempt to get to something or away from something. Elopement can occur for lots of different reasons, such as the child feeling overwhelmed and stressed. It can also just happen, for reasons not apparent to everyone else–but nevertheless important to the person doing the wandering.

A 2012 report by the Kennedy Krieger Institute found than nearly half of children with Autism Spectrum Disorders (ASDs) will elope. The problem is, that report was based on a parent survey, not a real, scientific study–so we really have no idea how prevalent autistic wandering is. Nor do we have any frame of reference for spectrum of elopement–how frequently does a child elope? How far does she usually go? Where does he go, and how much danger is he in? And most importantly, what triggers the elopement?

What we have is simply anecdotal evidence, and it’s not enough.