This work analyzes the temporal evolution for three active regions (ARs) (AR 2034, AR 2035, and AR 2036). In terms of complexity, these are objects with high a priori probability of flares. However, their actual flare scenarios proved to be very different. The temporal evolution of ARs is analyzed with modern prognostic parameters and descriptors obtained by methods of computational topology. We show that these methods are more suitable for describing the actual situation. We note that the change in complexity descriptors for prognostic problems is more important than the set of characteristics themselves.