How does this question leads to a Bias and please state the direction of the bias?

In a 1995 Corporation for Public Broadcasting poll of TV viewership, one question was, “A
recent study by a psychology professor at a leading university concluded that the amount of
violence children see on television has an effect on their likelihood of being aggressive and
committing crimes. From what you have seen or heard about this subject, do you agree
strongly with that conclusion, agree somewhat, or disagree strongly?”

1 Answer
Nov 18, 2017

It may sway readers to change their opinion towards "TV violence does affect aggression and criminal tendencies in children."

Explanation:

What we seek is people's opinion on the impact of TV violence on children's behaviour. (This can be denoted #X#.)

But, by presenting the results of a study as part of the question, people who read this result before giving their opinion will now be answering the question in light of new information. (This can be denoted #X|Y#, read as "#X# given #Y#".)

Think of it this way. Let's say you are interested in knowing how people feel about adding a mandatory statistics class to the high school curriculum. What you seek is the answer to, "Do you think a course in statistics should be added to the required courses taken by high school students?"

But when your question presents the results of a study that says some people think it's a good idea, your survey readers see this: "Hey, did you know that lots of people already think a statistics course should be required in high school? Do you agree with the crowd?"

Anyone who already thought it was a good idea will still agree.
Anyone who already thought it was a bad idea will likely still disagree.
But, anyone who was on the fence may feel pressure to "go with the flow" and also agree.

You see? By including information from a study, the responses you get will likely be skewed towards "agreeing with the study." People have a tendency to rationalize whatever they're thinking. Anyone who is strongly opinionated will likely not be affected by the study, but anyone undecided will take the study and use it to rationalize which position they should take, which will likely result in them siding with the study.

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There is another factor in this question that would cause bias: the possible answers. We only have "strongly agree", "somewhat agree", and "strongly disagree". If we were to match these to numbers on a scale from 1 (bad) to 5 (good), these response options would be equivalent to 5, 4, and 1. This is not a good spread; if we must limit ourselves to 3 options, we'd be better off with something parallel to 5, 3, and 1 (or perhaps 4, 3, and 2).

Also, anyone who is indifferent will need to "round" their opinion to either "somewhat agree" or "strongly disagree", and they'll probably think their opinion is closer to a "somewhat" than a "strongly".