Instrumental Analysis is a subject located in the second year in the Pharmacy degree. This is an obligatory subject with 5 ECTS.
The Department of Analytic Chemistry in the Faculty of Pharmacy is responsible for four groups of students; this work has been carried in a group shared by two professors with schedule of morning during the course 2007-2008 and with a total of 325 registered students. A high percentage of students had already been registered in this subject previously.
The aim of people involved in this project is the improvement of the learning process of this topic, the Analytic Chemistry that creates a great difficulty among the students of Pharmacy. It is necessary to find new educational strategies, more active, more attractive, more modern and more efficient, to make easy the study and the understanding of this subject and also to achieve the objectives of Bologna. With this aim we propose to incorporate a new learning method, a work group used as test group. Only the students belonging of this group received periodically material for working, and professor supervised the works carried out by these students. To prove the efficiency of this method, final qualifications obtained by these students were comparing with those obtained by the students belonging of a control group. Statistical test, parametric and non parametric, will performed with the aim to know the possible statistical difference between the two groups.
To know if we have achieved our purpose of advancing in the learning process a carefully statistical study had carried out. The sampling is an essential piece of the work. The Object Population consists on the total students registered in the well-known group A.
The official document of this register constitutes an appropriate mark of poll since it is a list of units well defined and completely identified.
Sampling will be applied in the Origin Population. Both populations are different because the selective factors appear between them, in this case, the probed class attendance. Before sampling, professors checked the attendance.
Once the Origin Population was established the level of knowledge of the students was verified with a test about practical and theoretical questions (basic knowledge of Mathematics, Analytical Chemistry and Physical Chemistry that student need to understand this subject) allowing books and notes.
Origin Population was divides in five sub-populations according with the basic level of knowledge showed in the test .
The variance of each sub-population is lower than the variance of the origin population, what means that groups relatively homogeneous were formed when the variable qualification was considered. This homogeneity justifies the use of the stratified sampling method that allows improving the precision of the estimations versus the simple random sampling method. Sample was obtained by the simple random sampling method in each of the stratus and the number of units took from each stratus was established by proportional assignment.
The 60 students that make up the stratified sample were arranged according to their qualification and by random balanced division. To assure the comparability of the groups, each student was assigned to one of the following groups: work group and control group.