Identify two major reasons why psychological research typically does not involve probability samples

What will be an ideal response?

a. We generally don't have the resources necessary to sample randomly. It would take considerable time, money, and energy to collect information from diverse groups of people. So we take the easier route most of the time, using college students. It is an imperfect strategy but it does yield useful results.
b. We may not be able to identify our population of interest specifically enough to be able to specify the population, so we cannot develop a sampling strategy that would generate a probability sample.
c. When psychologists engage in theoretical research, the population may not be of great interest. The test of a theory should produce the expected results, regardless of the nature of either the sample or the population.