A

Accidental Sample
This sampling technique makes no attempt to achieve representativeness, but chooses subjects based on convenience and accessibility. FOR EXAMPLE, the "person-on-the-street" interviews.

Activities
Services or functions carried out by a program (i.e., what the program does). FOR EXAMPLE, treatment programs may screen clients at intake, complete placement assessments, provide counseling to clients, etc.

After-Only Designs
One-shot studies; evaluation designs involving only measures taken after the program has been completed.

Analysis
A systematic approach to problem solving. Complex problems are made simpler by separating them into more understandable elements. This involves the identification of purposes and facts, the statement of defensible assumptions, and the formulation of conclusions.

Analysis of Covariance
A method for analyzing the differences in the means of two or more groups of cases while taking account of variation in one interval-ratio variable.

Analysis of Variance
A method for analyzing the differences in the means of two or more groups of cases.

Anchors
Anchors are items that serve as reference points from which other items in the series or other points in the scale are judged or compared. FOR EXAMPLE, the opposite ends or poles of a scale identify the extremes so all values within the scale are either greater or less than one of these extremes. Also, the scale midpoint serves as an anchor in that it either divides the scale into categories or quantifies the half value.

Applied Research
Research designed for the purpose of producing results that may be applied to real world situations.

Association
General term for the relationship among variables.

Asymmetric Measure of Association
A measure of association that makes a distinction between independent and dependent variables.

Attitude Surveys
Data collection techniques designed to collect standard information from a large number of subjects concerning their attitudes or feelings. These typically refer to questionnaires or interviews. FOR EXAMPLE, a questionnaire may be mailed to residents in a community to assess how 'safe' they feel in their neighborhoods.

Attribute
A characteristic that describes a person, thing, or event. FOR EXAMPLE, being female and male are attributes of persons.

Attrition
The loss of subjects during the course of a study. This may be a threat to the validity of conclusions if participants of study and comparison/control groups drop out at different rates or for different reasons. FOR EXAMPLE, if treatment participants fail to appear for treatment and are subsequently excluded from the follow-up, the treatment and control subjects remaining may not be "comparable" due to attrition.

Audit
The systematic examination of records and the investigation of other evidence to determine the propriety, compliance, and adequacy of programs, systems, and operations. The auditing process may include tools and techniques available from such diverse areas as engineering, economics, statistics, and accounting. The U.S. General Accounting Office auditing standards are applicable to all levels of government and not only relate to auditing of financial operations, but also are concerned with whether governmental organizations are: (1) achieving the purposes for which programs are authorized and funds made available, (2) operating economically and efficiently, and (3) complying with applicable laws and regulations.