D

Data
Documented information or evidence of any kind.

Data Analysis
The process of systematically applying statistical and logical techniques to describe, summarize, and compare data.

Data Collection Instrument
A form or set of forms used to collect information for an evaluation. Forms may include interview instruments, intake forms, case logs, and attendance records. They may be developed specifically for an evaluation or modified from existing instruments.

Data Collection Plan
A written document describing the specific procedures to be used to gather the evaluation information or data. The document describes who collects the information, when and where it is collected, and how it is obtained.

Database
A collection of information that has been systematically organized for easy access and analysis. Databases typically are computerized.

Demographic Question
A question used in compiling vital background and social statistics. FOR EXAMPLE, age, marital status, or size of household.

Dependent Variable
A variable that may, it is believed, be predicted by or caused by one or more other variables called independent variables. FOR EXAMPLE, if it is hypothesized that the treatment will reduce rearrest for drug us, then "rearrest for drug use" is the dependent variable, which is impacted by the independent variable or treatment.

Descriptive Statistic
A statistic used to describe a set of cases upon which observations were made. FOR EXAMPLE, the average age of a class in high school calculated by using all members of that class.

Design
The overall plan for a particular evaluation. The design describes how program performance will be measured and includes performance indicators.

Dichotomous Variable
A variable with only two possible values. FOR EXAMPLE, "sex."

Direct Benefit
Result that is closely related with the program by cause and effect. FOR EXAMPLE, increased adherence to probation restrictions is a result of participation in a compliance and sanctions program.

Direct Costs
Resources that must be committed to implement a program. FOR EXAMPLE, program staff salaries.

Direct Impact
An effect of a program that addresses a stated goal or objective of that program.

Discrete Variable
A quantitative variable with a finite number of attributes. FOR EXAMPLE, day of the month.

Dispersion
The extent of variation among cases.

Distribution of a Variable
Variation of characteristics across cases.

Document Review
A technique of data collection involving the examination of existing records or documents. FOR EXAMPLE, the examination of court documents to collect offender sentences.

Dummy Variables
A dichotomous variable, typically used in regression analysis, which indicates the existence (and lack of existence) of a characteristic or group of characteristics in a case. FOR EXAMPLE, "white/male - 0=No, 1=Yes."