There is a limit on how much effort a person can make in a given time slice. The best runners can only cover a quarter of a mile in one minute. The best analyst can only assimilate one stock quotation per second. The more effort a person makes per unit time, the shorter the time a person can sustain the rate of effort. A person can jog for hours, but can sprint for only seconds.
People have more choice-making opportunities than they have resources to make the choices.
They must therefore develop strategies deciding which choices to make and how much effort to spend on making those choices. This model posits that people expend their limited effort resources to achieve some set of desired end states, or goals. These goals may even be mutually exclusive. At any given time a person may be more aware of some goals and less aware of others. People will expend effort on choice making to the degree that they believe the effort will lead to some outcome they want.