1. A computer-implemented method for performing a data analysis task having an associated analysis context, the method comprising: defining the analysis context associated with the data analysis task, wherein data items have a variable relevance in accordance with the context, and wherein the data items are grouped together to form logical transactions conducted by a user over a predetermined time period; receiving the logical transactions exchanged over a communication network, wherein the logical transactions include a first data item type and a second data item type that is different from the first data item type; processing the logical transactions with a set of prioritization rules to generate relevance scores that quantify a relevance of the logical transactions to the analysis context, wherein the relevance scores are assigned according to a common scale; and generating a prioritization of the logical transactions based on the relevance scores.