Arbitrary sample
Arbitrary samples (choice at random, English convenience sampling ) are special selection procedures in empirical research . Elements from the population are included in the sample more or less arbitrarily (e.g. by an interviewer ) ; it is entirely at the discretion of the interviewer or the investigators themselves. The probability with which a certain element is included in the sample cannot be stated . The arbitrary sample is therefore not suitable for deriving inferential statistical (generalizing estimating) statements. It cannot be stated which population the respective sample refers to ( representativeness ).
Problems are distortions in the direction of the selection mechanism and self-selection .
Examples:
- Survey of people in a pedestrian zone ("Mall Interception Technique"): Overrepresentation of participants whom the interviewer wants to address and who are at the survey location at the time of the survey.
- Open online surveys ( online surveys in which participation is not limited to certain people): Overrepresentation of participants who use the Internet and go to the survey page.
literature
- Schnell among others: Methods of empirical social research. 1995, p. 279ff. ISBN 3486234897
- Andreas Diekmann : Empirical social research. Rowohlt-Taschenbuch-Verl., Reinbek 2002, p. 328ff. ISBN 3499555514