Certified Advanced Alcohol and Drug Counselor (CAADC) Practice Exam

The most important factors in test instrument selection are validity and reliability.

Validity refers to the extent to which a test measures what it claims to measure. It is crucial for ensuring that the results are meaningful and applicable to the population being studied. If a test is not valid, the conclusions drawn from its results may be misleading or irrelevant, leading to ineffective or inappropriate interventions.

Reliability, on the other hand, refers to the consistency of a test's results over time. A reliable test will produce similar outcomes under consistent conditions, which is essential for tracking progress and making informed decisions based on those results. Without reliability, it is impossible to ascertain whether observed changes are due to actual changes in the individual or fluctuations in the measurement process.

In contrast, the other considerations, while they may be relevant to specific contexts, do not hold the same weight as validity and reliability when it comes to the foundational aspects of test instrument selection. Factors like power and speed testing, test-retest construction, and developmental stages (concrete and pre-operational) may pertain to specific tests or contexts, but they are secondary to ensuring that the chosen instrument accurately and consistently measures the intended construct.