When a poll reports, for example, that 61% of the public supports a program of national health insurance, it usually also reports the sampling error. For example, a poll might report that the estimate is accurate to within plus or minus 3%. A classic essay in Time magazine ("How not to read polls," Apr. 2 1980) points out the following:
Readers consistently misinterpret the meaning of "warning label."... [The sampling error warning] says nothing about errors that might be caused by a sloppily worded question or a biased one or a single question that evokes complex feelings. Example: "Are you satisfied with your job?" Most important of all, warnirm labels about sampling error say nothing about whether or not the public is conflict-ridden or has given a subject much thought. This is the most serious source of opinion poll misinterpretation.
Carefully explain the difference between sampling error and non sampling error, both in general and in the context of the above quotation.