Sample
A subset of the population of interest selected for a research study.  It is a
finite portion that is used to study the characteristics of concern in the
population.


Sample distribution
A frequency distribution of all the elements of an individual sample.


Sample population
The population from which the sample is obtained.


Sample space
The collection of all possible outcomes of an experiment.


Sampling
The method of selecting a specified portion, called a sample, from a
population, from which information concerning the whole can be inferred.


Sampling distribution of the proportion
A frequency distribution of the proportions of many samples drawn from a
particular population. It is normally distributed.


Sampling distribution of the sample means
A frequency distribution of the means of many samples drawn from a
particular population. It is normally distributed.


Sampling distribution of the sample statistic
The probability distribution associated with the various values that the statistic
could assume in repeated sampling.


Sampling error
The estimated inaccuracy of the results of a study when a population sample
is used to explain behaviour of the total population.


Sampling fraction
The proportion of the number of sample elements to the number of population
elements.


Sampling frame
A listing of all elements in the sampled population.


Sampling interval
Taking a given number of units equally selected over the full population of
study. The nth number interval is derived by dividing the total number of units
by the sample number desired.  Also known as nth selection or interval.


Sampling unit
The elements available for selection at during the sampling process.


SAQ (self-administered questionnaire)
A questionnaire completed with no interviewer involvement.


Scale
A closed-ended question for measuring attitudes. A set of symbols or numbers
so constructed that the symbols or numbers can be assigned by a rule to the
individual (or their behaviour or attitudes) to whom the scale is applied.


Scaled-response questions
Multiple choice questions in which the choices are designed to capture the
intensity of the respondent's answer.


Screener
Questions used to screen for appropriate respondents.


Secondary data
Data that has been previously gathered.


Secondary research
Analysing information from previously conducted research projects. See also
primary research.


Sectional centre facility (SCF)
Geographic areas represented by the first three digits of a ZIP code.

Segmentation
See Market Segmentation

Selection
Process of choosing records using specific criteria from a population.


Selection bias
Systematic differences between the test group and control group because of a
biased selection process.


Selection error
Error that results from following incomplete or improper sampling procedures.


Selective perception
The ability of a listener or reader to filter out some information for conscious
or subconscious reasons.


Selective research
Research to choose among several viable alternatives identified by
programmatic research.


Semantic differential
A method of examining the strengths and weaknesses of a product or company
versus the competition by having respondents rank it between dichotomous
pairs of words or phrases that could be used to describe it; the mean of the
responses is then plotted in a profile or image. See also Likert scale.


Sentence and story completion
Tests in which the respondent completes sentences or stories in their own
words. The purpose of this technique is to enable participants to delve into
certain areas that they may otherwise find difficult to discuss.


Sequential testing
A testing procedure in which a respondent tries one product, evaluates it, then
tries and evaluates a second product.


Sex ratio
The number of males per 100 females in a population.


Shopper patterns
Drawings that record footsteps of a shopper through a store.


Short census form
U.S. Census Bureau questionnaire that all Americans answer every 10  years.


SIC (standard industrial classification)
Classification (in a four-digit code) of business as defined by the U.S.
Department of Commerce.  Pseudo SICs are SIC modifications which add a
fifth or sixth character to allow for greater specificity.


Sigmoid curve
The S-shaped relationship that allows the dependent variable to tend to 100
percent or 0 percent rather than actually get there. More lifelike than a straight
line in regression but harder mathematics.


Sign-out sheets
A control document used by a facility to keep track of co-op payments to
participants.


Significant difference
In mathematical terms, difference between tests of two or more variables.  The
significance difference varies with the confidence level desired.


Simple random sample (SRS)
A sample selected in such a way that every element of the population has a
known and equal chance of being chosen for the sample. Also called random
sample.


Simulated sales test
A procedure designed to estimate a product's sales potential by simulating trial
and use conditions of the marketplace.


Simulated test market (STM)
Alternative to traditional test market; survey data and mathematical models are
used to simulate test market results at a much lower cost.


Single-number research
Placing too much emphasis on a single statistic.


Site evaluation
Determining, through an analysis of a given area's demographic and economic
characteristics, whether it offers a good market for a product or service.


Skewed
A distribution whose frequency curve has one tail longer than the other - not
symmetrical about its mean.  If the left tail is longer than the right, it is called
skewed left.


Skip pattern
Requirement to pass over questions in response to respondent's answer to a
previous question.


Snowball samples
Samples in which selection of additional respondents is based on referrals from
the initial respondents.


Social indicator
A numerical measure of the quality of life.


Solomon four-group design
Research using two experimental groups and two control groups to control for
all extraneous variable threats.


Spearman rank-order correlation
Correlation analysis technique for use with ordinal data.


Specialized service or support firms
Companies that handle a specific facet of research, such as data processing or
statistical analysis, for many corporate clients.


Specifications
The criteria for participants in a focus group, involving their demographic
characteristics, product usage, product awareness, and so on.


Split-half technique
Method of assessing the reliability of a scale by dividing into two the total set
of measurement items and correlating the results.


Spurious association
Another variable or variables may cause changes in the dependent variable.


Stability
Lack of change in results from test to retest.


Standard deviation
The positive square root of average squared distance of the population or
sample values from the mean. It is the most widely accepted measure of
dispersion.


Standard error
The standard deviation of a distribution of sample means; the square root of
the variance of the sampling distribution.


Standard Metropolitan Statistical Area (SMSA)
An outdated U.S. Bureau of Census term for an area consisting of one or more
counties around a central urban area.


Standard normal distribution
A normal distribution with a mean of zero and a standard deviation of one.


Stapel scale
A scale, ranging from +5 to -5, that requires the respondent to rate how close
and in what direction a descriptor adjective fits a given concept.


Starting point
The first number selected of an Nth sampling interval.


State data centre
An organization within a state, generally a planning agency, university, or
library, to which the Census Bureau furnishes products, training in data access
and use, technical assistance, and consultation.


Static-group comparison
Pre-experimental design that uses an experimental and a control group.
However, subjects or test units are not randomly assigned to the two groups
and no pre-measurements are taken.


Statistic
A numerical quantity calculated from observations in a sample.


Statistical control
Adjusting for the effects of confounded variables by statistically adjusting the
value of the dependent variable for each treatment condition.


Statistical inference
Drawing conclusions about populations based on a sample.


Statistics
The science of collecting data, organizing or describing it, and ultimately
drawing conclusions from it.


Stochastic fancy
Phrase  for random or chance.


Strata
Segments of the population.


Strategic partnering
The alliance of two or more marketing research firms with unique skills and
resources.


Stratified random sample
Probability samples that force sample to be more representative of the
population. It is obtained by dividing the population into groups called strata,
then simple random samples are taken from each of the strata.


Structured observation
A study in which the observer fills out a questionnaire form or counts the
number of times an activity occurs.


Stub
The responses to the question being tabulated, which run vertically down the
left side of a computer table.


Sub-block
Along with enumeration districts, the smallest segment of the country for
which the U.S. Bureau provides demographic data.


Subject
The basic element on which the experiment or study is conducted.  Also
known as a participant, experimental unit, respondent, unit or unit of analysis.


Subjective question
A question that has no pre-listed answers which requires the respondent to
answer in his or her own words. Also known as open-ended question.


Sugging
Selling Under the Guise of market research
Marketing Under the Guise of market research (Mugging)


Sum of squares due to regression
The variation explained by the regression.


Sunbelt
The U.S. Census regions South and West.


Supervisor's instructions
Written directions to the field service on how to conduct a survey.


Surrogate information error
Error that results from a discrepancy between the information needed to solve
a problem and that sought by the researcher.


Survey objectives
The decision-making information sought through the questionnaire.


Survey research
Research in which an interviewer interacts with respondents to obtain facts,
opinions and attitudes.


Syndicated research
Studies in which the sponsoring research company defines the audience to be
surveyed and the interval between studies and the questions to be asked. 
Clients share the same results and costs.


Syndicated service research firms
Companies that collect, package and sell the same general market research data
to many firms.


Systematic sample
A procedure that selects every Nth unit (skip interval) of a population until the
desired sample size is reached.  The starting point should be a random position.


Systemic error
Error that results from the research design or execution.