The purpose of the study was to design, construct and validate the contents of an instrument that can be used to evalu- ate the performance of teachers at a Montessori school. The instrument was validated for pertinence, coherence and the drafting of each item. The assessment was done by three expert judges. Their reliability was determined through the con- cordance coefficient or Kappa index,
... [Show full abstract] which was high (complete agreement). Based on the results, 27 out of 102 proposed items were eliminated and 75 were left in the instrument to be applied. The focus of the instrument is on the dimensions of the teacher in terms of being, knowing, knowing how and being able to understand. A pilot application was done with 30 participants who teach at the Montessori British School, which is an institution that uses the Montessori method of education. In the analysis of internal consistency, obtained with Cronbach's alpha, the coefficients were high for all the dimensions evaluated (average .88).
