RESEARCH STUDY 12.3 Dr. Anderson Is a Nutritionist Who Helps Clients Lose Weight

RESEARCH STUDY 12.3
Dr. Anderson is a nutritionist who helps clients lose weight prior to surgery. She is working with a client (W. J.) who is a male 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 reduce the number of calories. A food journal is a book in which a person writes down everything he or she eats. She decides to phase in the food journal gradually, initially only being used 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. Each day, Dr. Anderson's client sends her the food journal and the number of calories he ate at each meal (as calculated by his wife, whose help she enlisted) . The data for Dr. Anderson's study are below.

-Refer to Research Study 12.3 above to answer the following question. Which of the following aspects of Dr.Anderson's study might be susceptible to observer bias?

A) The use of the food journal to track calories consumed
B) The conversion by Dr. Anderson of the food journal entries into calories consumed
C) The use of only one manipulation (e.g., the food journal)
D) The use of only one dependent variable
E) There is no risk of observer bias in Dr. Anderson's study