Abstract:

PBL has supposed an unquestionable change in low and high educational practices. Since it became popular in the 1960s it has been satisfactorily introduced into many fields of knowledge. Science is one of the areas with more applications of PBLs. Nonetheless, how to evaluate PBL practices is not an easy task. Should we evaluate all the tasks? Should we give a feedback to all the jobs? Has been the strategy followed adequate and useful? Are typical doubts within teachers.

Usual evaluation systems are typically quantitative, using numbers to assess learner achievement and are normally focused on how well a learning task is going on. This is the case of the summative evaluation system, between others. Formative assessments, on the contrary, give the possibility to ensure that the objectives of the learning are being achieved. In most of the cases, moreover, it provides useful information to identify the problematic aspects of the strategy carried out.

Although it has been preferably applied in lower educational levels we propose a formative assessment to carry out together with a Problem Based Learning strategy within an experimental subject of the degree in chemistry. The principal objective of this methodology is to go deeper in the Analytical chemistry knowledge of students; therefore, it will be applied in the fundamental or in the advanced block of the degree. That is, in the second or in the third course.

For the development of the methodology we proposed a strategy which combines seminaries and experimental work in the laboratory. In the first session the teacher will introduce the problem in hands, which will be the common threat for the next sessions. The problem proposed is based on the parameters usually used to define the quality of drinking water. In this way some concepts belonging to the field of analytical chemistry will be addressed, such as acid-base titrations, atomization techniques for elemental analysis, techniques for molecular analysis, etc.

The tasks proposed (bibliographic searches, the elaboration of a first report, and the design of the experimental work to do in the lab…) will be carried out individually and/or in groups. The evaluation process will also be mixed, including evaluations from the teacher, evaluations from the other students, and also self-assessment. Students, therefore, would be evaluated and evaluators, so the evaluation would suppose less time consuming, and will involve all the students. Meanwhile the PBL strategy carried out will also be analysed.

In order to verify the applicability of the combination of PBL and formative evaluation the methodology proposed here would be simultaneously applied in two different faculties of the University of the Basque Country; in the Science and Technology faculty in Bilbao, and in the faculty of Chemistry in Donostia-San Sebastián