We are carrying out a three-year research which purports to assess to what extent teaching and assessment methods of university professors have an influence on how students learn (Biggs, 1993; Pintrich and Schrauben, 1992; Ramsden, 1985; Valle, González Cabanach, Núñez and González-Pienda, 1998). The conclusions herein exposed are the result of our first year of work and they refer to professors. Due to the lack of an assesment instrument fitted to our research objectives, we developed a questionnaire for this purpose (TAMUPQ, Teaching and Assessment Methodology of University Professors Questionnaire), based on previous works of other researchers (Dall'Alba, 1991; García Valcárcel, 1993; Gow and Kember, 1993; Kember, 1997; Kember and Gow, 1994; Martin and Ramsden, 1992; Samuelowicz and Bain, 2001). This questionnaire evaluates the conception of learning, the teaching and assessment methodology, as well as teaching abilities of a competent professor. It is a 51-item questionnaire divided into three scales: the first scale, consisting of 16 items, understands the conception of learning as a reproduction of what it is established in subjects, and a traditional view of teaching and assessment; the second scale, consisting of 17 items, understands knowledge, teaching and assesment from a constructivist point of view; the third scale, consisting of 18 items, evaluates the most important teaching abilities: planning, information for students, preparation of lessons, a methodology appropriate to objectives, an evaluation consistent with well-established and public criteria, etc. The questionnaire is constructed using Likert-scale format with five possible answers for each item, ranging from "strongly disagree" to " strongly agree". The questionnaire was validated with a sample of 233 professors from the two public universities of the city of Valencia (Spain): the University of Valencia/Estudi General (UVEG), and the Polytechnic University of Valencia (UPV). Previously, we had carried out a representative sampling of professors from both universities, which was balanced proportionally for both of them, with a level of confidence of 95% and a maximum margin of error of 5%. The questionnaire obtained a high degree of internal consistency: Cronbach's alpha coefficient was .879 for the first scale, .832 for the second scale, and .839 for the third scale. Later, we performed a hierarchical cluster analysis following k-means procedure using as classifying variables those factors found in every scale (during the validation of the questionnaire, these factors were obtained through an analysis of principal components with varimax rotation for each scale) and we found out five groups of professors with the following characteristics: Group 1 (43 professors): professors more focused on learning than in teaching from a conceptual viewpoint, with constructivist ideas, but traditional in their work: they use a traditional and descriptive methodology and examination as method of assessment. Group 2 (76 professors): professors more focused on teaching than in learning from a conceptual viewpoint -traditional conception of teaching-, who use traditional methodologies of teaching and assessment and with some gaps in necessary teaching abilities. Group 3 (46 professors): professors focused on learning -constructivist conception- and with teaching abilities: they use diverse and complementary methodologies as well as formative assessment methods. Group 4 (36 professors): traditional professors, focused on teaching and with educational abilities: good planning, use of diverse and complementary methodologies as well as use of examination together with other assessment procedures. Group 5 (31): traditional professors, focused on teaching and with educational abilities: good planning, use of a mainly descriptive methodology, allowing other complementary methodologies and a conception of summative assessment, through examination. The results show that the dimensional structure of different styles is complex and also that they interact in a complex way with teaching abilities. During the second year, taking these results as a starting point, we have chosen professors with different teaching and assessment styles and we are monitoring them and their students, in order to examine to what extent their methods have an influence on how students deal with learning.