The same data collection methods and sources are available when conducting training evaluation. Some common methods for collecting evaluation data include interviews, questionnaires, direct observation tests and simulations, and archival performance data. Questionnaires are most often used in HRD evaluation because they can be completed and analyzed quickly. Any or all of these methods are appropriate for collecting evaluation data, depending on their relevance to the questions being asked.

Interviews can allow for clarification and greater depth of answers; however, they can be both costly and time-intensive, and require a trained interviewer. Questionnaires can be relatively low cost, and allow for anonymous answers; however, respondents may misunderstand some questions, or simply not fill them out. Written tests can also be relatively low in cost and are easy to administer; however, a possible limitation is whether or not the test is valid for the job in question, like whether the test is truly related to job performance.

Direct observation can be an excellent way to measure behavioral change; however, a concern is whether individuals will act differently if they know they are being observed. There are many trade-offs in determining the most appropriate data collection method to use for evaluation purposes.