Quick sign-in first — it saves your answers so you can come back and find your results later. Totally free; this is purely so your data isn't lost, and there's no spam, ever.
Your responses are saved to your account so you — and only you — can revisit them.
You'll see a series of faces. For each one, drag the slider to your best guess of how old she was when the photo was taken. At the end you'll get a score for how good your guesses were.
Anonymous. Your guesses (and, if not already known, your age & gender) are recorded to study how well people read age from faces — nothing that identifies you.
Saved to your account, and matched to Glosso's questions so your answers carry over if you ever sign up there.