This article introduces innovative methodological aspects of an intervention research that followed the model development paradigm proposed by Rothman and Thomas (1994). It focuses on the design process, measuring fidelity and its graphic representation, and the use of current technology such as computer-assisted qualitative data analysis software (CAQDAS). The measurement process for estimating fidelity is explained, as well as how qualitative and quantitative methods can be integrated. How the results of the observation of the implementation process are displayed graphically in an innovative and precise way is shown. Implications for future research are discussed.