Professor Victor Vroom is renowned for his work on the theory of motivation in which he examines why people choose to follow a particular course of action.
In Work and Motivation, Vroom defines the central problem of motivation as "the explanation of choices made by organisms among different voluntary responses". To understand how these choices are made, he defines the three concepts of valence, expectancy and force, and describes how these work in conjunction to determine how people will decide to act, given possible routes of behaviour leading to possible outcomes.
Is a term referring to a preference for one outcome over another. An outcome is said to be positively valent when a person prefers attaining it to not attaining it; when he or she prefers not to attain an outcome, then it has a negative valence; and when he or she is indifferent to whether an outcome is attained or not, it has a valence of zero. The valence of an outcome, Vroom suggests, is directly related to its value for the person concerned. If a manager particularly wants a promotion, for example, and thinks that successful completion of a certain project will earn that promotion, then he or she will attach a positive valence to completing the project, and be motivated to do so by the perceived value of the reward.
A person's behaviour, however, is affected not only by their preference for one outcome over another, but also by how likely they believe these outcomes to be. Vroom defines expectancy as "a momentary belief concerning the likelihood that a particular act will be followed by a particular outcome" (p.17). Expectancy can be assigned a value from zero (the belief that the outcome will not follow on from the action) to one (the belief that the outcome certainly will follow on from the action). If someone wants a cup of coffee, for example, and knows that there is a drinks machine in the staff room, that person will walk straight there. The act of walking there has a high expectancy value in terms of obtaining coffee, whereas the act of walking to, say, the post room has a low expectancy value, as the person does not believe that he or she will find coffee there.
The third concept which Vroom outlines is force. He argues that a person's behaviour is the result of a field of forces, each of which has direction and magnitude. Mathematical values assigned to the valences and expectancies for acts are combined to produce their hypothetical force, and the act which produces the highest level of force is assumed to be the one that the person will choose. Highest levels of force will be produced by actions with high levels of both valence and expectation. If either valence or expectation is zero, there will be no force to adopt that course of action, since anything multiplied by zero is zero.
Vroom's model is summed up in an equation:
M = [Sigma] (E x V)
M is the motivational force resulting from the sum of expectancy and valence, E is the expectancy measure reflecting the probability of a particular first level outcome and V represents the valence for the individual of a particular outcome. (Source: Martin, J., (1998), Organizational Behaviour, London, International Thompson Business Press)
Vroom's theory can be put into practice by interviewing individuals or giving them questionnaires to assess their expectancies and valences. These are then scored, and the expectancy score is multiplied by the valence score. The results for all outcomes that could be produced by a particular behavioural alternative are added together. This gives the expected value (EV) of that alternative. Each possible course of behaviour can be assigned an EV in this way, and the model predicts that the one with the highest EV will be a subject's most likely choice....