Final answer:
The number of participants in a study divided by the number initially chosen for the sample is called the response rate. The response rate is crucial in ensuring that the research findings are reliable and valid, considering that high attrition rates can lead to a biased representation of the population.
Step-by-step explanation:
The number of participants in a study divided by the number initially chosen for the sample is called the response rate. In research studies, especially those involving surveys, it is important for the sample of participants to be representative of the larger population. However, if individuals refuse to participate, or if there is a high dropout rate, it can result in a decline in response rate and potentially bias the results. This is a critical concept in research methodology as it pertains to the reliability and validity of the study's findings. Researchers must often address attrition rates by recruiting more participants than needed, anticipating that some will drop out over the course of the study.