  Document ranking based on probabilistic evaluations of relevance is known to
exhibit non-classical correlations, which may be explained by admitting a
complex structure of the event space, namely, by assuming the events to emerge
from multiple sample spaces. The structure of event space formed by overlapping
sample spaces is known in quantum mechanics, they may exhibit some
counter-intuitive features, called quantum contextuality. In this Note I
observe that from the structural point of view quantum contextuality looks
similar to personalization of information retrieval scenarios. Along these
lines, Knowledge Revision is treated as operationalistic measurement and a way
to quantify the rate of personalization of Information Retrieval scenarios is
suggested.
