Answer to Question 1
The first researcher could measure the size of the pumpkins by placing them on a scale. Because weight is concrete, as opposed to hypothetical, there is no doubt that the researcher really is measuring size. Also, the scale can be checked for accuracy and reliability. As a result, the first researcher has no concerns about reliability or validity. The second researcher, however, is measuring self-esteem which cannot be measured directly. Therefore, the second researcher will need to develop an operational definition and will need to demonstrate that the operational definition really is measuring self-esteem and is measuring reliably.
Answer to Question 2
b