Program Evaluation Glossary

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Needs Assessment: A systematic process for gathering information about current conditions within a group that underlie the need for an intervention.
Nominal Variable: A quantitative variable whose attributes have no inherent order.
Nonequivalent Comparison Group Design: Evaluation designs that use nonrandomized comparison groups to evaluate program effects. Also referred to as quasi-experimental designs.
Non-experimental Data: Data not produced by an experiment or quasi-experiment.
Non-probability Sample: A sample not produced by a random process.
Non-respondent: A person who fails to answer either a questionnaire or a question.
Non-response Bias: The bias created by the failure of part of a sample to respond to a survey or answer a question. If those responding and those not responding have different characteristics, the responding cases may not be representative of the population from which they were sampled.
Normal Distribution (Curve): A theoretical distribution that is closely approximated by many actual distribution of variables.
Normative Question: A type of evaluation question requiring comparison between what is happening (the condition) to norms and expectations or standards for what should be happening (the criterion).
Null Hypothesis: A hypothesis stating that two variables are not related. Research attempts to disprove the null hypothesis by finding evidence of a relationship.