Control beliefs have to do with the perceived presence of factors that
may facilitate or impede performance of a behavior. It is assumed that
these control beliefs — in combination with the perceived power of each
control factor — determine the prevailing perceived
behavioral control. Specifically, the perceived power of each control
factor to impede or facilitate performance of the behavior contributes to
perceived behavioral control in direct proportion to the person's
subjective probability that the control factor is present (see perceived behavioral control).