RESUMO
Background: Portfolio is an innovative instrument that promotes reflection, creativity and professionalism among students. Aitn: To describe the development and validation process of a questionnaire to evalúate the use of portfolio in undergraduate medical students. Material andMethods: Focus groups with students and teachers were employed to identify aspects related with portfolio in undergraduate teaching. The Delphi technique was used to prioritize relevant aspects and construct the questionnaire. The validated questionnaire, consistingin 43 Ítems and 6factors, was appliedto 97students (response rote of99.9 percent) in2007and 100students (99.2 percent) in 2008. Each question had to be answered using a Likert scale,from 0 (completely disagree) to 4 (completely agree) The validity and reliability of the questionnaire was evaluated. Results: The questionnaire showed a high reliability (Cronbach alpha = 0.9). The mean total scores obtained in 2007 and 2008 were 106.2 ± 21.2 (61.7 percent ofthe maximal obtainable score) and 104.6 ± 34.0 (60.8 percent ofthe maximal obtainable score), respectively No significant differences were seen in the analysis by factors. Changes in portfolio during 2008 showed differences in Ítems related with organization, evaluation and regulation. Conclusions: The questionnaire is a valid and highly reliable instrument, measuringperceptions about the portfolio by undergraduate medical students. The students perceived an improvement in their creativity and professionalism as one ofthe strengths of portfolio. The weaknesses identified during the implementation process helped us to focus changes in organization and evaluation to improve the portfolio as a dynamic process.