A manual used by the Dallas County district attorney's office from 1968 to 1976 advised, "Do not take [. . .] a member of any minority race on a jury no matter how rich or well educated."
a. Was this an attempt to bias trial results at the sampling stage or at the stage where jurors must reach a conclusion of guilty/not guilty?10
b. In this example, which of these best describes the source of bias: using a volunteer sample, sampling frame not matching population, using a convenience sample, taking a haphazard sample?