TRA and TPB measures can use either 5- or 7-point scales. A person’s behavioral beliefs about the likelihood that performance of the behavior will result in certain outcomes are measured on bipolar “unlikely-likely” or “disagree-agree” scales. Evaluationsof each outcome are measured on bipolar “good-bad” scales. For example, one outcome of “my quitting smoking” may be that this “will cause me to gain weight.” A person’s behavioral belief about this outcome is measured by having him rate the likelihood that “my quitting smoking will cause me to gain weight.” The person’s evaluation of this outcome is measured by having him rate the degree to which “my gaining
weight” is good versus bad. These behavioral belief and evaluation ratings are usually scored from 3 to+3, capturing the psychology of double negatives, where a belief that a behavior will not result in a negative outcome contributes positively to the person’s attitude. An “indirect measure” of the person’s attitude toward per-the behavior is computed by first multiplying her behavioral belief concerning each outcome by her corresponding outcome evaluation ratings and then summing these product scores across all outcomes of the behavior.