  The results of the National High School Examination (ENEM) are an important
tool for a diagnosis of educational deficiencies at the end of a training
cycle. This exam is a relevant source of data for the evaluation of what is
learned by high school students. In this paper, thirteen selected questions are
presented, from the Natural Sciences exam in the period between 2009 and 2014,
questions that were classified as "physics questions", in which the
alternatives reveal well-delimited non-scientific conceptions described in the
literature. From the students' performance on these items, observations about
the learning process in physics in basic education are made. This study reveals
that there are some permanent difficulties in understanding basic concepts of
mechanics, thermal phenomena and geometric optics. Many of these questions
point to the presence and even predominant role of non-scientific conceptions
described in the research literature in physics teaching. Even knowing how
difficult it is to modify these conceptions, the results reveal that, despite
all the research effort in physics teaching since the 1980s, there was little
impact of the results in the learning process, and only a few changes
incorporating this knowlege in the didactic materials and in the teacher
training courses. (Paper in Portuguese.)
