Acta Universitatis Danubius. Relationes Internationales, Vol 9, No 1 (2016)

Abstract

When talking about the error made ​​during the conduct of surveys, usually is reported only one type of error, the simplest one that is identifiable and relates to the study of population sampling. One such error constitutes, as it were, "the tip of the iceberg" in the totality of the errors that are made during the survey process. It is calculated with the formula, or inferred from the so-called "curve of error depending on the sample size". This error is issued only for the types of probabilistic sampling. It will express statistically, errors we make when the results obtained from the study of sampling units seek to extend to all units in the study population.

Other errors are those associated with the reduction of the degree of representativeness of the sample to the population strata in the study. Also, unknown error it is one that enters by the decline of the quality of the interviews, or by the use of (on the last link of the sampling) a final quote. Another one is introduced by the lack of sincerity in respondents' answers when using probabilistic sampling tip and use questionnaires with questions perceived by the respondents as delicate.