A needs assessment is a systematic process for determining and addressing needs, or "gaps", between current conditions and desired conditions or "wants". Needs assessment is part of planning. It can be used to clarify problems and identify appropriate solutions. Needs assessments require sufficient data. Needs assessments can help improve policy or program decisions, individuals, education, training, organizations, communities, or products. There are three types of need in a needs assessment; perceived need, expressed need and relative need. Perceived needs are defined by what people think about their needs, each standard changes with each respondent. Expressed needs are defined by the number of people who have sought help and focuses on circumstances where feelings are translated into action. A major weakness of expressed needs assumes that all people with needs seek help. Relative needs are concerned with equity and must consider differences in population and social pathology. Considered the "father of needs assessment", Roger Kaufman developed a model for determining needs defined as a gap in results. This particular emphasis in results focuses on the outcomes that result from products, processes, or inputs. Kaufman argues that an actual need can only be identified independent of premature selection of a solution. To conduct a quality needs assessment according to Kaufman, determine the current results, articulate the desired results, and the distance between results is the actual need. Once a need is identified, then a solution can be selected. Kaufman's model identifies needs at the societal level, "Mega" planning, along with needs at the Macro (organizational) and Micro level (individuals and small groups). Organizational elements vary among the three different levels: outcomes at the Mega level, outputs at the Macro level, and products at the Micro level. Extensive research uses a large number of cases to determine the characteristics of a population while intensive research examines one or a few cases in depth.