| A process model of interpersonal influence was presented focusing on dyadic influence. The model included the determinants of influence propensity, the evaluation of resources and alternative means of influence, the selection of an influence strategy, and influencing behaviors (issuing a directive, reasoning, and using resources).;The model was tested in the context of vendor selection for purchase decisions which were in the process of being determined. The sample consisted of 100 purchasing professionals from 21 large firms in the chemical and allied products industry. Subjects were personally interviewed regarding their potential influence over the vendor preferences of decision participants from other departments. A follow-up mail survey, administered three weeks later, focused on the means of influence used and their effectiveness.;Results indicated that influence propensity is a function of perceived benefits interacting with influence norms, and the need for power interacting with perceived decision outcome risk. Combinations contributing in a positive direction are high benefits with weak norms, low benefits with strong norms, a high need for power with low risk, and a low need for power with high risk.;In evaluating resources, the greater the influencee's dependency on the purchasing manager for a resource, the greater is the expected influence. This effect is contingent upon the probability of the influencee selecting the influencer's preferred vendor in the absence of an influence attempt. Specifically, the greater this probability, the greater is the contribution of resource dependency to expected influence.;When evaluating influence strategies, the greater the influencee's aggregate resource dependency, the greater is the purchasing manager's expected influence from both issuing a directive and using resources. Aggregate resource dependency however, was not found to be a predictor of expected influence from reasoning. In selecting an influence strategy, consideration is given to cost-effective approaches.;When attempting influence, the greater the number of influence approaches used, the greater is the interpersonal influence. This effect is contingent upon the pre-influence probability of the influencee selecting the influencer's preferred vendor. Specifically, the greater this probability, the weaker is the relationship between the number of influence approaches used and interpersonal influence. |
