The article presents a research into oral mediation of complex abstract texts by means of one
language without translating into a second language. The research examines the hypothesis
that the success of the communicative task achievement depends on the number of mediation
strategies involved and the right choice of the major strategy. To set the background for the
research, a brief historical review of mediation is provided; the research methods, results and
implications are described. The primary focus is on the social importance of mediation for
educational institutions.