unobserved

adj

1. (not-comparable)Not seen or observed.

   “Such practices as Theſe, too groſs to lye / Long unobſerv'd by each diſcerning Eye, / The more judicious Iſraelites Unſpell'd, / Though ſtill the Charm the giddy Rabble held, […]”

   “The relation of the logit formula to the distribution of unobserved utility (as opposed to the characteristics of choice probabilities) was developed by Marley, as cited by Luce and Suppes (1965), who showed that the extreme value distribution leads to the logit formula.”

adv

1. (not-comparable)Whilst not being seen or observed.

   “The visitors we do not encourage are the many small boys who slip in unobserved and are a danger to themselves and the staff.”