The development of a theory-based method of estimating the impact of p
harmacy clerkship students on clerkship sites is described. A job-anal
ysis approach was used to estimate the impact of pharmacy clerkship ac
tivities on the clerkship sites. Two models - an employee model and a
nonemployee model - of the student-preceptor relationship were used to
evaluate clerkship student activities. Pairs of clerkship students an
d their preceptors were interviewed about student activities and super
vision. Activities were assigned three-digit codes expressing (1) the
level of preceptor supervision required, (2) the necessity of the acti
vity to the functioning of the site, and (3) the complexity and amount
of patient contact involved. The fit of each activity to the models w
as determined, and the impact of the clerkship students on a composite
clerkship site was estimated. Twelve pairs of clerkship students and
preceptors were interviewed. Degree of required supervision was the pr
imary determinant in assigning an activity to a model. Student activit
ies that tit the employee model were determined to have the greatest p
otential for having a positive or negative impact on the clerkship sit
e. Performance of nonemployee-model activities could represent a net l
oss to the site because of the demand on preceptors' time. A method of
categorizing and evaluating the value of specific student activities
at pharmacy clerkship sites was useful in estimating student impact on
the productivity of the site.