Dr. Anderson is a nutritionist who helps clients lose weight prior to surgery. She is working with W. J., a male client who is planning on undergoing a heart transplant. He currently eats more than...

Dr. Anderson is a nutritionist who helps clients lose weight prior to surgery. She is working with W. J., a male client who is planning on undergoing a heart transplant. He currently eats more than 3,500 calories a day and has been asked by his doctor to cut the number of calories to about 1,800 (400 for breakfast, 600 for lunch, and 800 for dinner). She is curious as to whether a food journal will help W. J. reduce the number of calories he eats. A food journal is used to record everything a person eats to help patients be more aware of what they’re eating. W. J.’s wife also recorded the food he consumed at each meal to have complete data before introducing the journal. Dr. Anderson decides to phase in the food journal gradually, initially only having W. J. record what he ate at breakfast during the first three days after baseline (days 4–6). During days 7–9, the journal is used at lunch, too, and during days 10–12, it also is used during dinner. The data for Dr. Anderson’s study are below.

Question:

In interrogating the construct validity of Dr. Anderson’s study might be asked:
A)
How accurate was W. J.’s wife in her calculation of the calories consumed at each meal?

but in interrogating the statistical validity. his study might be asked:
B)
By what margin did W. J.’s calorie intake improve?

I thought A is also interrogating the statistical validity. Why asking A can be considered as interrogating the construct validity? I am confused with the differences between A and B. Please explain. (no handwriting please)

Extracted text: 1800 1600 1400 1200 1000 Breakfast 800 Lunch 600 Dinner 400 200 I 2 3 45 7 9 10 II 12 Day Number of Calories Consumed