This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
[{'content': 'Cronbach alpha is a measure of \nSelect and explain. \nA. Internal consistency, B. Content validity, C. Central tendency, D. Standard deviation', 'role': 'user'}, {'content': "Answer: A \nExplanation: Cronbach alpha / Guttman's lamdba 3 :\n\nIs measure of internal consistency.\nValue lies between 0 to +1.\nValue +0.7 or more is considered satis factory.", 'role': 'assistant'}]