M

Management
The guidance and control of action required to execute a program. Also, the individuals charged with the responsibility of conducting a program.

Management Information System
An information collection and analysis system, usually computerized, that facilitates access to program and participant information. It is usually designed and used for administrative purposes.

Marginal Distribution
The distribution of a single variable based upon an underlying distribution of two or more variables.

Matching
A method utilized to create comparison groups, in which groups or individuals are matched to those in the treatment group based on characteristics felt to be relevant to program outcomes.

Matrix of Categories
A method of displaying relationships among themes in analyzing case study data that shows whether changes in categories or degrees along one dimension are associated with changes in the categories of another dimension.

Maturation Effect A threat to the internal validity of an evaluation in which observed outcomes are a result of natural changes of the program participants over time rather than because of program impact. FOR EXAMPLE, age cohorts generally mature and/or change crime commission tendencies over time. This may naturally alter crime commission patterns independent of program participation.

Mean
A measure of central tendency, the arithmetic average; a statistic used primarily with interval-ratio variables following symmetrical distributions. FOR EXAMPLE, the average age or average height of a group of middle school students.

Measurement
A procedure for assigning a number to an object or an event.

Measurement Error
The difference between a measured value and a true value.

Measures of Association
Statistics that indicate the strength and nature of a relationship between variables.

Measures of Central Tendency
Measures that indicate the midpoint or central value of a distribution. These measures include the mean, median, and mode. FOR EXAMPLE, one measure of central tendency of a group of high school students is the average (mean) age of the students.

Median
A measure of central tendency, the value of the case marking the midpoint of an ordered list of values of all cases; a statistic used primarily with ordinal variables and asymmetrically distributed interval-ratio variables.

Meta-analysis
The systematic analysis of a set of existing evaluations of similar programs in order to draw general conclusions, develop support for hypotheses, and/or produce an estimate of overall program effects.

Methodology The way in which information is found or something is done. The methodology includes the methods, procedures, and techniques used to collect and analyze information. FOR EXAMPLE, questionnaires or use of secondary information.

Mission The part of a goal or endeavor assigned as a specific responsibility of a particular organizational unit. It includes the task, together with the purpose, which clearly indicates the action to be taken and the reasons.

Mode
A measure of central tendency, the value of a variable that occurs most frequently; a statistic used primarily with nominal variables.

Monitoring
An on-going process of reviewing a program's activities to determine whether set standards or requirements are being met.

Monitoring System
An on-going system to collect data on a program=s activities and outputs, designed to provide feedback on whether the program is fulfilling its functions, addressing the targeted population, and/or producing those services intended. FOR EXAMPLE, a computerized intake system may be utilized which captures client characteristics, and subsequently provides monthly reports on the numbers of clients processed and receiving services.

Mortality Threat
A threat to the internal validity of an evaluation caused by participants withdrawing or dropping out prior to program conclusion. FOR EXAMPLE, the impact of the success of a drug awareness program is difficult to assess in a school with a high attrition rate.

Multivariate Analysis
An analysis of the relationships between more than two variables.