Final answer:
Validity refers to measuring what it's supposed to measure, while reliability refers to consistency. A valid measure accurately measures a construct, while a reliable measure produces consistent results. Both reliability and validity are important considerations in data collection.
Step-by-step explanation:
Validity refers to the extent to which a given instrument or tool accurately measures what it's supposed to measure. For example, if a research study is measuring intelligence, the study would be considered valid if the instrument used accurately measures intelligence and not something else. Reliability, on the other hand, refers to the consistency of a measure, meaning that the same results are produced given the same circumstances. So, if a research study consistently produces the same results when measuring intelligence, it would be considered reliable.