Research Methods

Home Visits

We're interested not only in what babies know when they come into the lab, but also what their home environment is like, from their perspective. To look at this, we go to families' homes, and put small light-weight cameras on a headband or hat, and record an hour of what infants are seeing and hearing every month.

There are two little cameras, one pointed slightly up, and one pointed slightly down, so that we can ensure we capture what babies see when they have something close to them, and when they look up at caregivers. A third camcorder records the global properties of the environment.

We also record all the audio input babies get in a typical day once a month using small recording devices (LENA recorders). This gives us a longer-and probably more typical--recording to figure things out about the language infants are hearing.


When babies come into the lab, we want to know what they know. Since babies understand a lot more than they say, we use their eye-movements as a way to see what they know. To do this, we have babies sit in their parent's lap in front of a special computer that has an eyetracking camera at the bottom of it (we use a remote eyetracker called the Eyelink 1000 Plus ).

During the study, babies see some pictures or videos on a screen and hear a sentence telling them to look at a specific picture or video. The computer and camera automatically measure where they look, and then we use that information to figure out what words they understand.

Analyses, Coding, and Modeling

Back in the lab, we have a stellar team of research assistants and lab technicians that help us crunch through this data and test hypotheses about what's driving early word learning, using corpus methods, and statistical models of the data.


We take the data we collect very seriously and never share any of it in any way without parents' written permission. That said, with parents permission, we share the recordings we get with other researchers using data-sharing libraries like CHILDES and Databrary .