The report provides a brief summary of the findings of work on data irreversibility relatedto the impact of the on-line filtering of data on the potential to discover yet unkown andperhaps even unexpected signals. For the time being we focus on radio astronomical datastreams to develop approaches and methods to evaluate the impact of on-line filtering onthe discovery potential. We found an unified approach to describe the filtering of differentkinds and identified preliminary approaches to measure the amount of information in datastreams in the framework of the Shannon information theory. We present a possible way togeneralize the signal detection procedure in the context of the statistical signal detection andshow a particular example how this generalization influences the signal discovery potential.