Q

Qualitative Analysis
An analysis that ascertains the nature of the attributes, behavior, or opinions of the entity being measured. FOR EXAMPLE, in describing a person, a qualitative analysis might conclude that the person is tall, thin, and middle-aged.

Qualitative Data
Information that is difficult to measure, count, or express in numerical terms. For example, how safe a resident feels in his or her apartment is qualitative data.

Qualitative Research
Research involving detailed, verbal descriptions of characteristics, cases, and settings. Qualitative research typically uses observation, interviewing, and document review to collect data.

Quantify
To attach numbers to an observation.

Quality Control
A procedure for keeping quality of inputs or outputs to specifications.

Quantitative Data
Information that can be expressed in numerical terms, counted, or compared on a scale. FOR EXAMPLE, the number of  911 calls received in a month.

Quantitative Analysis
An analysis that ascertains the magnitude, amount, or size, for example, of the attributes, behavior, or opinions of the entity being measured. FOR EXAMPLE, in describing a population, a quantitative analysis might conclude that the average person is 5 feet 11 inches tall, weighs 180 pounds, and is 45 years old.

Quantitative Research
Research that examines phenomenon through the numerical representation of observations and statistical analysis.

Quasi-Experimental Design
A research design with some, but not all, of the characteristics of an experimental design. While comparison groups are available and maximum controls are used to minimize threats to validity, random selection is typically not possible or practical.

Questionnaire
A printed form containing a set of questions for gathering information.

Quota Sampling
A nonprobability stratified sampling procedure in which units are selected for the sample to adhere to certain proportions of characteristics desired. FOR EXAMPLE, an interviewer is instructed to interview 100 individuals in a mall (half male and half female). If the interviewer obtains 50 female interviews first, only males will be interviewed until that quota is also met.