Q-sorting
A sophisticated form of rank ordering using card sorts.


Q-spread
The distance between the first and third sample quartiles.


Qualitative Research
Research data not subject to quantification or quantitative analysis;
characterized by the absence of empirical measurements and an interest in
subjective evaluation.  Often used in developmental research, using
elicitative, probing techniques, to generate salient attributes, opinions,
scales, etc..
Qualitative methodologies include focus groups, mini-groups,
and depth interviews (usually face-to-face).  All these methods are usually
recorded (often transcribed) and interpreted later.


Quantitative variable
A variable whose values are classifications or categories and are not subject to
qualitative interpretation.  Examples include sex, occupation, marital status,
etc.


Quantitative research
Research conducted for the purpose of obtaining empirical evaluations of
attitudes, behaviour or performance. Designed to generate projectable numerical
data about a topic.


Quantitative variable
A variable whose values are numerical in nature. Examples include weight,
age, income, etc. Quantitative variables are further classified as being either
discrete or continuous.


Quartiles
The division of the observation distribution into quarters (in the same way the
median divides the distribution in half).


Quasi-experiments
Studies in which the researcher lacks complete control over the scheduling of
treatment or must assign respondents to treatment in a non-random manner.


Questionnaire
A set of questions designed to generate data necessary for accomplishing the
objectives of the research project.


Quota sample
A sampling procedure that includes specified numbers of respondents having
characteristics known or believed to affect the subject being researched.
Selection is by non-probability means. A moderator might set a quota of having
half the group be users of Brand X, or one-fourth be aware of Product Y.