Sifting is the best method cuz all the dirt will be carried by wind.
Answer:
Option c. Inter-rater Reliability
Explanation:
Here, the rating is done by a group of data collectors under training for evaluation children's pain on Faces scale which is a scale ranging from 0 to 10 with different expressions or faces with a happy face at 0 to a crying face at 10.
Also in Inter-rater Reliability, the relative consistency of a study or test is assessed and the extent to which different group members rated the same behavior, the consistency of which is evaluated.
Thus it can also be helpful in interviews, etc.