Random in one's state of knowledge. For example, if you have tossed a coin, but not yet looked at it, you would still treat it as a 50:50 odds if asked to bet, but actually it is already in one state or the other, you just don't know which. Contrast with ontologically random.
Also used in hcistats2e: Chap. 1: page 7
Used in glossary entries: ontologically random