This paper presents the semantic framework for the description and automatic
composition of the data analytical processes. The framework specifies how to describe
goals, input data, outputs and various data operators for data pre-processing and
modelling that can be applied to achieve the goals. The main contribution of this paper is
the formal language for the specification of the preconditions, postconditions, inputs and
outputs of the data operators. The formal description of the operators with the logical
expressions allows automatic composition of operators into the complex workflows
achieving the specified goals of the data analysis. The evaluation of the semantic
framework was performed on the two real-world use cases from the medical domain, where
the automatically generated workflow was compared with the implementation manually
programmed by the data scientist.
