question: What is the main idea of the passage ?
answer: a survey on the relations between children 's happiness and their parents ` ability to earn in Sydney
turker_answer: The maid idea of the passage is a survey on the relations between children 's happiness and their parents ` ability to earn in Sydney .
rule-based: The main idea of the passage is a survey on the relations between children 's happiness and their parents ` ability to earn in Sydney .