Question

The owner of a large company is conducting a survey about job satisfaction, including questions about salary, hours, stress, and other conditions. There are about eight hundred employees in the company, including one hundred executive positions, six hundred fifty middle-management positions, and fifty custodial positions. The owner wants to include about ten percent of his employees in the survey sample.

Identify a sampling method that might produce a biased sample. Explain why using the method for this survey would be a poor choice.