Final answer:
A valid instrument for collecting data on dietary supplements accurately measures what it is intended to measure, ensuring the results truly reflect dietary supplement usage.
Step-by-step explanation:
An instrument to collect data on the use of dietary supplements would be viewed as valid if it measures accurately what is intended to measure. Validity is crucial in research studies involving dietary supplements as it ensures that the results are indeed about the dietary supplement usage. Valid instruments or tools used to collect data do so in a way that truly reflects the phenomenon being studied. For instance, a questionnaire with closed-ended questions that collects quantitative, numerical data can provide statistical analyses of dietary supplement usage patterns if designed with validity in mind, ensuring accurate reflections of the topic of study.