biased sample

(redirected from Sample bias)
Also found in: Medical.

biased sample

[¦bī·əst ′sam·pəl]
(statistics)
A sample obtained by a procedure that incorporates a systematic error introduced by taking items from a wrong population or by favoring some elements of a population.

biased sample

a population SAMPLE which is not a true reflection of the parent population (see BIAS 2), i.e. not a REPRESENTATIVE SAMPLE.

When the incidence of a certain occurrence or piece of behaviour in a population is to be investigated, e.g. voting intention, it is often impossible to examine the total population, so a sample of this population is taken. For this sample to produce acceptable data, it must be a true representation of the parent population, so it is essential that it is selected in a way that ensures this. If this is not managed, bias will result and the information collected will not truly reflect the population being studied. Thus, to select a sample by questioning people in the street will bias it against people who do not walk, do not go shopping, are at work or school all day Postal QUESTIONNAIRES attempt to overcome this type of bias, but are likely to be biased against those who do not bother to fill in questionnaires and re turn them, and against the illiterate. To keep bias to a minimum, if random sampling is not possible, it is necessary to select the sample carefully by matching all relevant parameters of the population, e.g. age, class, residence, etc, and to ensure as high a response rate as possible, probably by personal INTERVIEWS.

Mentioned in ?
References in periodicals archive ?
The quasi real time data are also constructed such that the difference between estimates of output gap from real time data and that from quasi real time data reflects data revision and the difference between estimates of output gap from final data and that from quasi real time data portray other revisions including end sample bias.
12286/full) one study found that the research supporting detox teas were full of sample bias, small samples, and flawed methodology .
2 The Vendor shall also describe any unusual designed features to accelerate or decelerate the electrons, such as combined acceleration anodes and sample bias.
Stambaugh (1999) emphasizes the severity of small sample bias as the reason behind poor predictability.
But when Bristol researchers took a closer look at the research - which took a year to be sent to them under a Freedom of Information request - they identified what they said was missing data, sample bias and poor research design.
However, with regard to sample bias in the strong group, when Wiseman (2003) investigated strength of belief in luck in the United Kingdom, the weak group accounted for 14.
Sample bias may have influenced the model presented (Fig.
Among such issues are the sources of sample bias and how to compensate for the bias, appropriate units of analysis and techniques of quantitative analysis, the importance not only of large and diverse reference collections but also of information on the natural history of the fauna represented in an assemblage, and how methods link to research issues of concern to California archaeology generally.
Solution #2: To address sample bias, take these three steps:
It would be interesting for the AOP or College to research how deep this discourse is or if what I hear is heavily skewed by sample bias.