*2.2. Measurement Instrument*

The instrument adapted is the *Indoor Physical Environment Perception* scale (iPEP scale), a 1–7 Likert scale. Students had to rate the degree of the learning space variables from 1 (low degree) to 7 (high degree). In the process of adaptation to the primary school context, the number of independent variables has been reduced to fourteen: Academic (the course), sex and age, and the physical learning space (11 variables); as well as two dependent variables: The GPA (Grade Point Average) obtained in the subjects of Mathematics and Arts. The statement of these items has been modified for students between the ages of 9 and 13. In addition, the variables School and Classroom were created in the database, based on the data obtained. The items related to the physical learning space are the following:


*Sustainability* **2020**, *12*, 2020

