In Avery v. State, 514 P.2d 637 (Alaska 1973) the supreme court adopted the rule that, in this situation, the police officer's testimony should normally be confined to the fact that the officer's investigative efforts were prompted by information received from the informant--and that a trial judge should normally employ Evidence Rule 403 to bar the officer from repeating the details of the informant's tip (presumably, unless an understanding of a particular detail is necessary for an understanding of a particular investigative effort). Avery, 514 P.2d at 644-45.