An information determination apparatus includes a first storage unit configured to store stream data pieces obtained in time sequence; a first determining unit configured to determine whether the number of stream data pieces stored in the first storage unit is at least equal to a predetermined value; and a second determining unit configured to determine, when the number of the stream data pieces stored in the first storage unit is equal to or greater than the predetermined value, whether an individual can be identified based on a dataset composed of a plurality of the stream data pieces stored in the first storage unit, and output the dataset used for the determination and the determination result.