Traditionally, physics subjects are evaluated by asking students to solve numerical problems in such a way that teacher verifies, not only that students get the correct results, but also the use of correct solving problems methodologies.

In four bachelor’s degrees of the Universitat Politècnica de València (Aerospace Engineering, Electrical Engineering, Industrial Electronics Engineering and Industrial Design Engineering; about 500 students enrolled each year), Physics courses students have been following blended assessment. One or two days before the usual written exam, students take an online exam (usually numerical questions rather than multiple choice questions). The exam tool is part of the software application called PoliformaT, developed by the Universitat Politècnica de València through the Sakai project. Each student has a different exam, randomly generated from question pools. These online exams are part of the blended assessment and their main objective is to allow students to detect their weaknesses before the written exam. The detailed description of this blended assessment, and its validation, have been published elsewhere (references in the full version of this paper).

It is well stablished that feedback plays a very important role in the learning process. Some authors (Coll et al. 2014; Alvarez et al. 2012) suggest that when teacher offers feedback based on suggestions, the students are able to progress with their learning. In this paper one way of articulate teacher feedback is presented: performing a PoliformaT exam as a classroom practice, at the computer if the classroom has them or hardcopy otherwise. Students must solve the exam in groups of two or three members. These exams are designed as a bridge between the standard problems solved by the teacher, and the online assessment described above.

In order to fulfil their requirements, the most relevant features of these exams are:
- Exams include answer boxes in which students must write numerical figures.
- Exams are not limited to pose a problem and ask for the final result. Instead, students must demonstrate that they know the solving method. For example, if a problem requests the acceleration of a system, it is provided a set of equations that students must complete.
- The questions and the set of answer boxes are designed to detect the most common mistakes. This is an indirect way of highlight them, enabling active learning.
- Exams are performed during class hours. They consume a relative high amount of hours; for example, in a course of 90 hours, nearly 20 of them correspond to class in which these exams are performed.
- These exams are intended for provide teacher feedback and then do not contribute to the subject assessment. The teacher-students ratio is around 1 to 40.
- The exam is evaluated immediately, either by the online application, or by an answers sheet. The main advantage is that students can ask the teacher about their mistakes getting instant feedback.
-Students can solve the exam several times to improve their expertise.
- The exam is also available online, so students can repeat it limitless, although without the possibility to obtain immediate feedback from the teacher.