To demonstrate disparate impact under condition (1) above, a plaintiff must identify a specific employment practice when possible to separate the employer’s practices, and show that it results in a significantly higher percentage of a protected group in the available population being rejected for employment, placement, or promotion. One method of evaluating whether such a disparity exists is called the four-fifths rule. This rule states that discrimination typically occurs if the selection rate for one group is less than 80 percent of the selection rate for another group.