Vagueness, fuzzy transform, F-transform, fuzzy natural logic, componentsof time series

In this paper, we discuss the difference between probabilistic and fuzzy techniques used in time series analysis. First, we focus on the fundamental difference between vagueness and uncertainty phenomena. Then we briefly describe probabilistic view of time series. In the main part, we demonstrate how special fuzzy techniques, namely the fuzzy natural logic and fuzzy transform can be applied in the analysis of time series and what is their outcome in comparison with the probabilistic approach.We argue that fuzzy techniques enable to obtain knowledge that is eithermore difficult or impossible to obtain using probabilistic techniques.