Project-Based Learning (PBL) in Bioengineering - Advanced Design and Manufacturing Technologies for Biomedical Devices - page 331

that have proved their worth in prior research or in teaching experiences like the one
described in this document.
When the projects or problems to be solved are tackled in a group, certain stu-
dents usually take on the role of leaders, while others tend to “let themselves be led”
or even cease to participate, particularly if the fi nal mark is the same for all members
of the group.
Our understanding is that the alternatives for putting an end to this situation are
to assign individual projects, although somewhat easier tasks than would be assigned
to a group of students, supplement student assessment with co-assessment (among
students of the same team) either including some individual component that is usu-
ally a result of their class participation, or a supplementary exam. In whichever
case, the presence of “parasite” students that benefi t from others' efforts may also
turn out to be good experience for the most assiduous students to prepare them-
selves for the reality of the world of work.
On other occasions, PBL experiences give students some freedom when propos-
ing the problem or project to be solved. This can boost creativity and be highly
enriching if common goals are sought. However, this can sometimes lead to consid-
erable discrepancies in the projects' degree of diffi culty or the amount of time
required to complete them, which, in turn, will make it more diffi cult for teachers to
carry out the assessment. To limit these diffi culties, teachers can resort to verifying
(or modifying) the projects put forward by students by offering the freedom to
choose from a wide list of possible projects or a selection of monographic studies
with certain variations (toy design, the synthesis of certain mechanisms, the devel-
opment of products for a single sector, etc.).
On the other hand, when PBL experiences are conducted in a subject over several
consecutive courses, there is a repetition of some similar developments, which
makes it much easier to copy works from other years. Therefore, it is not advisable
to use the same fi eld or area of application for the projects being developed for more
than three or four courses. It is also highly advisable in product development-related
courses to allocate each course a different single topic in order to avoid a gradual
loss of creativity and the inevitable “ageing” of the topic dealt with. This is also
applicable to other experiences such as student competitions and other play-based
activities.
A more diffi cult problem to solve, especially when PBL experiences are linked to
product development (including defi ning specifi cations, conceptual design, select-
ing alternatives, basic design, detailed design and, on occasions, prototype produc-
tion), is the diffi culty in reaching the detailed design stage, above all, if the
experience is linked to a single subject that is only timetabled for a 4-month period
or semester.
Obviously, defi ning the specifi cations for a new product and proposing and eval-
uating alternatives for a thoroughly explored conceptual design stage are complex
but enriching tasks. However, they are also slow to carry out, which is why some
subjects devote whole PBL experiences to the “detection of a relevant need” and
“conceptual design” phases.