In the case of internal auditors, the population considered was made up of those discharging their functions in
Spanish municipalities from 20,000 inhabitants onwards. The establishment of a bottom limit at the level of
20,000 inhabitants is founded on the fact that that is the size determined by Spanish local regulations (LRBRL,
art. 26) from which councils have to deliver social services in a compulsory way. At the same time, the authors
considered that councils under that size would not have enough resources to accomplish an effective internal
control on their performance, at least on the terms required by Spanish Law.
As previously explained, the size of the population of internal auditors was determined by the number of Spanish
councils exceeding 20,000 inhabitants, which amounted to 387 in 2010 (National Institute of statistics, INE). On
the other hand it must be taken into account that this population was comprehensive of a wide variety of sizes in
terms of inhabitants or population covered. The number of inhabitants is related to the volume of budget and
resources available. This fact suggested dividing the population into different strata (see table 1), on an attempt
to obtain more homogenous groups. Besides, this division by strata would allow exploring the diversity of
perceptions of internal auditors belonging to councils of different size.