The document discusses methods for gathering data to measure the return on investment of training sessions. It identifies qualitative and quantitative data gathering techniques including questionnaires, surveys, tests, interviews, focus groups, and observation. It also outlines different levels of data gathering based on the needs of the analysis from basic feedback questionnaires to more in-depth skills evaluations, interviews, and program follow up. Sources of data include participants, supervisors, subordinates, peers, records, and staff. Key factors in designing effective questionnaires are ensuring they are valid, reliable, easy to administer, protect anonymity, and are cost effective.