90% isn't all that great of a result considering only about 6.7% of the US population suffers from depression each year[1] and the study was done in California. Just returning false would give you better accuracy.
Still Eliza on steroids is pretty cool. Can't wait till they integrate it into emacs.
They give their hypothesis in the paper, and each is shown with a p value < 0.05, so is statistically significant (and better than just returning false :)
p values are a measure of the accuracy of the numbers. They are measuring how close the sample mean is to the population mean. In the case of the paper, the p values represent how close the sample mean of the head gaze, eye gaze, smile intensity and smile duration measurements are to the population means of the same values.
Still Eliza on steroids is pretty cool. Can't wait till they integrate it into emacs.
[1] http://www.nimh.nih.gov/statistics/1MDD_ADULT.shtml