Data
The collection of observations.


Data processing
Organization of data for the purpose of producing desired information; involves
recording, classifying, sorting, summarizing, calculating, disseminating and
storing data.


Data User News
A monthly newsletter issued by the U.S. Census Bureau.


Database management software
Computer programs in which data are captured on the computer, updated,
maintained and organized for effective use and manipulation of data.


Day-after recall
An advertising testing technique that measures the proportion of people
recalling seeing a TV commercial within 24 hours of its airing.


Daytime population
The population of an area during the daytime, which is usually far different
from the residential population measured by the census.


Decennial census
The census that is conducted by the U.S. Census Bureau every 10 years in the
first year of the decade.


Delphi technique
Method of expert judgment without adequate hard data, e.g., long-term
forecasting. Stage I is to poll experts, anonymously and separately. In Stage 2
the results are consolidated and fed back to the experts as a group. Stage 3
polls them individually again, in the light of peer group opinion. In theory, the
process continues until consensus arrives.


Demographics
Description of the vital statistics or objective and quantifiable characteristics
of an audience or population. Demographic designators include age, marital
status, income, family size, occupation, and personal or household
characteristics such as age, sex, income, or educational level.


Demography
A social science concerned with the size, distribution, structure, and change of
populations.


Density
A measure that is computed by dividing the total population of a geographic
unit by its land area measured in square miles or square kilometres.


Dependent variable
A symbol or concept expected to be explained or caused by the independent
variable.  It is the variable measured on each subject to determine whether its
value is affected by the independent variable. Also known as criterion variable.


Depth interview
One-on-one interviews that probe and elicit detailed answers to questions, often
using nondirective techniques to uncover hidden motivations.


Descriptive function
The gathering and presentation of statements of facts.


Descriptive studies
These studies answer the questions who, what, when, where, how.


Design control
Use of the experimental design to control extraneous causal factors.


Diagnostic function
The explanation of data or actions.


Diary panel
A survey in which the same respondents keep a diary of what they watch,
listen to, or buy, etc., over specified period of time.


Dichotomous questions
Questions that ask the respondents to choose between two answers.


Digitizing
The process of assigning latitude and longitude coordinates for each twist and
turn of a market area that is to be studied.


Direct computer interviewing
Consumers are intercepted in a mall or other central location and interviewed
by a computer that asks questions and accepts responses.


Directory database
Data available through directories or indexes of directory-type data.


Disappointment score
The proportion of respondents in a product test who indicate, after trying the
product, that they would not buy it.


Discrete variable
A quantitative variable that can assume a finite or at most a countable number
of values such as the number of children in a family.


Discretionary income
The amount of money people have for spending after taxes and necessities are
paid for. Also known as disposable income.


Discriminant analysis
A multivariate technique for analysing the predictive value of a set of
independent variables.


Discriminant coefficient
Estimate of the discriminatory power of a particular independent variable.


Discriminant score
The basis for predicting to which group a particular object or individual
belongs.


Discriminant validity
The lack of association among constructs that are supposed to be different.


Discussion guide
A written outline of topics to cover during a focus group discussion. See also
moderator guide.


Discussion question
A question which has no pre-listed answers and thus allows the respondent to
answer in his/her own words. Also known as open-ended question.


Disguised observation
The process of monitoring people, objects, or occurrences that do not know
they are being watched.


Disk-by-mail (DBM)
Self-administered surveying using a computer-based questionnaire which is
mailed to participants.


Disposable income
The income available to persons for spending or saving after taxes have been
deducted. Also known as discretionary income.


Disproportional or optimal allocation
Sampling in which the number of elements taken from a given stratum is
proportional to the relative size of the stratum and the standard deviation of the
characteristic under consideration.


Distribution check
A study measuring the number of stores carrying specified products, along with
the number of facings, special displays, and prices of the products.


DMA (Designated Marketing Area)
A television market, as defined by NPD/Nielsen, a firm which measures TV
audiences.


Door-to-door interviewing
Consumers are interviewed face to face in their homes.

Double Byte, UNICODE
Standard methods for dealing with non-European writing systems
such as Arabic or Japanese and which are supported by the latest
browsers and international versions of most operating systems.


Double jeopardy
The marketing problem in which smaller brands are bought both less
frequently and by fewer people.


Double sampling
Data is collected through an inexpensive sampling technique for a sample
larger than the final desired sample size. A sub-sample of this group is then
selected and sampled - usually with a more expensive technique.


Duplicate number validation
A service in the focus group industry in which the names and telephone
numbers of people recruited for groups are submitted to a central screening
organization in advance of the groups for the purpose of screening out people
who have recently participated in any session or are involved in focus groups
more frequently than is desired.


Dyad
A qualitative research methodology in which an interviewer works with two
participants at once. This technique is particularly appropriate for products and
services for which two persons are relatively equal partners in making a
purchase decision.