  There is growing recognition that the overall client-vendor relationship, and
not only the contract, plays a critical role in Information Technology
Outsourcing (ITO) success. However, our understanding of how ITO relationships
function is limited. This paper contributes to this understanding by reviewing
empirical literature on ITO success in terms of relationship satisfaction. A
key finding is that the majority of reviewed studies concentrates on client
satisfaction, thus neglecting the vendor perspective. We argue that this raises
questions about the construct validity of these studies. Consequently, concerns
exist about the validity and reliability of their empirical findings. Some
scholars have acknowledged the problem and use a dyadic perspective. However, a
review of these studies reveals that the authors have underestimated their
contributions and do not explain why there is a problem. Therefore, the purpose
of this paper is to highlight their contributions by comparing the findings of
the dyadic perspective studies with those of the "client perspective" research.
In doing so, we assess whether the dyadic studies produce better explanations
for ITO success than the client-oriented studies. We argue that this is indeed
the case, by producing a better view on how underlying mechanisms of ITO
relationships work.
