Final answer:
Validity refers to the accuracy of a claim, measurement, or conclusion. Reliability indicates the consistency and repeatability of a study's findings. Operational definition ensures that variables are measured in a precise and replicable manner.
Step-by-step explanation:
The term validity refers to how accurate or appropriate a claim or conclusion is. On the other hand, how repeatable or consistent a study finding can be is known as reliability. How well a variable has been manipulated or measured is referred to as operational definition.
Validity is about the correctness and appropriateness of a claim or measurement, ensuring that a study measures what it is intended to measure. Reliability refers to the consistency and repeatability of the study's findings, indicating that the results can be replicated if the study is reproduced. The operational definition is critical in a study as it defines every concept or variable in terms of physical or concrete steps required to objectively measure it, ensuring that data can be collected in a systematic and replicable manner.
To clarify, a reliable measurement consistently produces the same results under the same conditions, much like a kitchen scale giving the same reading every time a fixed amount of cereal is weighed. However, the scale's validity comes into question if it is not properly calibrated and does not measure the cereal's weight accurately.