Psychometric Evaluation

The process of assessing whether a measurement instrument (such as a questionnaire or survey) possesses desirable statistical properties including validity, reliability, and consistency. In accessibility and usability research, psychometric evaluation is used to determine whether instruments like the System Usability Scale accurately and reliably measure what they claim to measure. Key properties assessed include internal reliability (whether items correlate with each other), criterion validity (whether scores correlate with other established measures), and construct validity (whether the instrument measures the intended real-world phenomenon).