Existing socioeconomic databases were used to ensure a fair population sample. Once identified, the interviewees were telephoned and asked to complete a short questionnaire with a trained interviewer.

为了确保公平性所选择的的人群样本全部使用现有的社会经济数据库，受访者打电话有专门经过培训的工作人员询问，并且在受访期间要求填写一份简短的问卷。

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For example, if an employer can demonstrate that a typing test and skills tests using Microsoft Office software products constitute a fair sample of the content of an administrative assistant job, then the tests will probably be considered content valid.

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To be fair, Hulbert does note that he was looking at a small sample size and that there have been instances where the CAPE ratio has stayed at high levels before a bear market set in.

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