MARKET RESEARCH GLOSSARY - N |
NA
No Answer
The accepted abbreviation to indicate no response to a question because the respondent refused to reply, the question did not apply or it was skipped for some reason.
National Proportions
The characteristics of the country where a research project is being conducted.
Natural Observation
The observation of behaviour in a natural setting.
Nested Sample - see Multi-Stage Sample
Neutral Value
Usually the mean of all responses to a question and it can be used as a substitute for a missing response.
NH or NAH
Not at Home
The accepted abbreviation to indicate that the respondent is not at home, there is no answer to the doorbell or the telephone.
Noise
Noise can be used to refer to a random variation in some data due to uncontrolled sources.
Nominal Group Technique
A type of face-to-face group discussion that is designed to minimise the group effect (where participants moderate their opinions and go along with a majority view). Participants are asked to consider a subject and then discuss it with one other member (or a small number of members) of the group before presenting it to the whole group.
Nominal Scale (aka Classified Scale)
A scale where the numbers act only as data labels (eg 0=male, 1=female or a social security number). The only analysis that can be performed is to observe how frequently each of the scale members occurs in the survey.
Non-Comparative Scale
A scale where each object is measured independently of the other objects in the same test and absolute results are obtained.
Non-metric Correlation
A correlation measure for two non-metric variables that relies on rankings to compute the correlation.
Non-Metric Data
Data that cannot be analysed statistically, such as that from a nominal or ordinal scale.
Non-Metric Multidimensional Scaling
A perceptual mapping technique that is based on an analysis of non-metric data such as rank ordering.
Non-Parametric Test
A test that involves non-metric data (ie data that comes from nominal or ordinal scales).
Non-Probability Sample (aka Non-Random Sample)
A sample in which the selection of units is based on factors other than random chance, eg convenience, prior experience or the judgement of the researcher. Examples of non-probability samples are: convenience, judgmental, quota and snowball.
Non-Random Sample - see Non-Probability Sample (above)
Non-Response Error
A type of non-sampling error caused by some sub-groups of the sample responding less than the rest of the sample.
Non-Sampling Error
Any error caused by factors other than sampling error. Examples of non-sampling error are: selection bias. population mis-specification error, sampling frame error, processing error, respondent error, non-response error, instrument error, interviewer error and surrogate error.
Norm
The standardised or hypothesised value against which a sample statistic is compared.
Normal Distribution
A symmetrical bell-shaped statistical distribution where the mean, the median and the mode all have the same value.
Normative Data - see Measures of Central Tendency
Null Hypothesis
A statement to be tested that is usually expressed in a negative (or null) way and suggests that no difference or effect is expected. If the statement is disproved, then the null hypothesis is rejected and the alternative hypothesis is accepted.
Numerical Scale
A type of scale where the intervals are represented by numbers (as opposed to pictures or words).