For the first time, recently developed time-series classification based on qualitative space fragmentation (QSF) was applied to simple and complex voltammetric responses and their components in order to describe peak shape and symmetry. Symmetrical and asymmetrical reduction signals were obtained experimentally by square wave voltammetry (SWV) and differential pulse polarography (DPP) in model systems. It was found that, through the properties of color matrices, the method recognizes (a) symmetry of the peaks as well as some other details - not visible by the naked eye. Therefore, it could be useful to accept symmetry and shape of the electrode response as additional diagnostic criteria during studies of unknown processes, i.e. to introduce the mentioned treatment of voltammetric responses as a new branch of software packages for signal processing. (C) 2013 Elsevier B.V. All rights reserved.