The study proposes the utility of time series methodology in the study of processes in educational psychology. Conjointly, the study applies time series in the study of cognitive achievement. Thirteen students from seventh to ninth grades performed an inductive reasoning test. The performance was measured in 20 different occasions and the observations were aggregated to generate a times series of 260 observations (20 different occasions by each individual multiplied by 13 participants). Result shows that a seasonal ARIMA (0,0,1) (1,1,1) adequately fits the data through a model comparative approach. Concluding, despites the complexity, ARIMA methodology is capable to investigate process, reducing the object of the study without lost its fundamental properties and dynamical aspects. Article visualizations
