The strength of an appraisal technique is gauged by its conformity to the criteria for legal defensibility.

The legal defensibility criteria include reliability, validity, fairness, job-relatedness, and non-discrimination. These criteria ensure that the appraisal technique is based on objective measures and is not influenced by subjective factors such as personal bias or discrimination. Adhering to these criteria enables a company to defend the appraisal technique in court, if necessary. Therefore, the strength of an appraisal technique is determined by its conformity to these criteria.