Substantial agreement on a five factor structure - the so-called "Big Five" - to represent personality structure has been reached in these last years. Psycholexical studies in several countries have produced similar structures that nonetheless at a closer inspection reveal some cross-cultural instability, especially for some dimensions. One possible explanation for this instability is that often studies relied on different criteria to select variables. This hypothesis has been tested in this contribution by comparing two independent psycholexical studies conducted in Italy and based upon different selection procedures. Analyses have been performed on the common set and the specific sets of adjectives and comparing the factorial solutions to a marker Big Five measure. Results suggest that the factorial structures recovered in the two studies are highly similar but they do not match exactly to the Big Five. Differences in selection criteria did not influence the results, with the exception of the fifth factor (Mental Openness/Intellect).