Validity refers to the suitability of the investigative procedure to answer the question asked.

• A. The speed of the experiment.
• B. The reliability of the measuring device.
• C. The suitability of the procedure to answer the question, controlling conditions as needed.
• D. The number of repeats performed.

Answer: (C)

Validity means asking whether the method used is appropriate to answer the question you’re investigating. If the procedure is suitable and you control variables that could influence the outcome, the results will reflect the factor you’re studying rather than something else, so the investigation can validly address the question. That’s why focusing on how well the procedure fits the question, with necessary controls, is the key idea.

Speed of the experiment doesn’t determine whether it answers the question, and reliability of the measuring device is about whether measurements are consistent, not whether the method itself is appropriate. Similarly, the number of repeats affects precision and reliability, but even many repeats won’t fix a fundamentally unsuitable approach.