Abstract:

Project-Based Learning methodologies are increasingly applied in the most diverse areas from social courses to technical subjects. The focus of the selected project varies from analysis and discussion of certain relevant aspects of the subject to the completion of a technical project with all the results and documents related to it.

In the latter case, the success of the PBL depends on the selection of the appropriate hypotheses and on the correctness of the numerical results. The evaluation of these outputs cannot be based on a group discussion or in an easy review of the deliveries of the students. The problem arises when considering a populated class of 60 or 70 students gathered in about 15 different groups assigned with a project having different inputs, as is the case of the undergraduate course of Soil Mechanics in the School of Architecture of the UPM (Madrid). A thorough evaluation and review of all the projects may be extremely time-consuming for the teacher resulting in an ineffective PBL method.

We define the Iterative Silent Feedback (ISF) as a method to solve that problem and, at the same time, increase the student proactivity in its learning process.
The ISF is based in a semi-automated procedure to thoroughly review the numerical results obtained by the students in the project. The teacher prepares an excel-type form, based on different groups variable data, where the students should introduce those results in a certain order. The form creates an ordered group of data in an excel sheet (checking sheet) that the teacher can compare with the correct excel-based solution of the problem. This check takes only minutes and the wrong data can be marked, for example, with a special color in the checking sheet.

The teacher gives the marked checking sheet back to the students with no other comments (or maybe only some comments for clarification). This is the reason why it is called “silent feedback”. Instead of receiving the correct solution, the students only get the wrong/right marks and should rethink the hypotheses made and the decision-making process followed to obtain the results. In our opinion, this process is far more instructive than the regular procedure. Besides, the wrong/right marks, and eventually some comments, allow the teacher to redirect the work of the students when it goes along the wrong path.

After rethinking the work done, the students are welcome to deliver the project again and the process may be repeated until the results are completely correct. This is the reason why it is called “iterative feedback”. The flexibility of this iterative process is reported by the students with a very positive assessment. They also indicate that using this method they become strongly aware of the difficulty of obtaining an error-free project and of the necessity of following a detailed audit process in every technical project.

From the point of view of the teacher, an enormous reduction of the correction time is achieved at the same time that a thorough review is performed.

Keywords:

Project-based learning, assessment, feedback, large classes.