Which concept describes consistency of measurement across test items measuring the same construct?

• A. Internal consistency reliability
• B. Content validity
• C. Construct validity
• D. Predictive validity

Answer: (A)

Internal consistency reliability describes how consistently the items on a test measure the same construct. When items are intended to tap the same attribute, responses should tend to move together, producing meaningful correlations among the items. A common statistic, Cronbach's alpha, summarizes these inter-item correlations and the number of items; higher values indicate the items hang together well, suggesting a reliable measure of that construct. This differs from content validity (whether items cover the intended domain), construct validity (whether the test relates to related constructs in expected ways), and predictive validity (whether the test forecasts future outcomes). So, when the question asks about consistency of measurement across test items measuring the same construct, internal consistency is the best fit.