Predicted probabilities that a subject generated the eye movement sample are evaluated using the log loss metric.
Log loss is defined as:
$$\text{log loss}=-\frac{1}{N}\sum_{i=1}^N\sum_{j=1}^My_{i,j}\log\left(\hat{y_{i,j}}\right),$$
where
\\(N\\)
is the number of samples,
\\(M\\)
is the number of subjects,
\\(\text{log}\\)
is the natural logarithm,
\\(\hat{y_{i,j}}\\)
is the posterior probability that the
\\(j^{th}\\)
subject generated the
\\(i^{th}\\)
sample, and
\\(y_{i,j}\\)
is the ground truth
(\\(y_{i,j}=1\\)
means that the
\\(j^{th}\\)
subject generated the
\\(i^{th}\\)
sample,
\\(y_{i,j}=0\\)
means that they did not).