a means of measurement, the application of which is similar to that of the first stages of the thurstone scale, using the method of apparently equal intervals and based on stephenson's q-technique, was elaborated, by using this tool it was planned to carry out a study on the function perception of the public health educator on the health team. the study comprises two phases: the first dealing with the construction of the instrument it self and the second with the making of a research survey, using the same. it is described every step of the first phase which consists of: gathering of information on the function assigned to the public health educator; list of the functions; turning them into statements transcribed into cards; selection of a sample of 70 cards, by a highly specialized board of judges; tabulation of the data obtained and definition of the definitive instrument. to fulfil the requisites of validity the scaling distribution should present a certain balance among the pertinent, intermediate, and non-pertinent statements. for statistical convenience and to guarantee such a balance each judge is told to place varying numbers of cards on several piles, turning its totality into a continuum approaching a normal or nearly normal distribution. such a balance has been attained and a distribution of the frequency statements sampled by the judges has shown an excellent internal agreement which qualifies this study as satisfactory. the statements have been proved to be definitive components of the measuring tool - percep？？o da fun？？o do educador na saúde pública (perception of the function of the educator in public health).