It is assumed that the psychological structure of a practical task (as compared with a theoretical, or cognitive task) can be conceptualized only as a system of tasks regarded as a unity of mono-problem and multi-problem characteristics. Psychological specificity of practical tasks is seen by the author in their content, in the manner of realization of their components, and in the relations (contradictions) between the latter; all these in their turn are determined by objective qualities of the object and of the means of corresponding practical (work) activity, by the most general experimental aims, and by the theoretical ideas of the sides participating in the experiment concerning the psychological mechanisms of development and functioning of thinking.