Bridging levels of ``granularity'' and ``scale'' are frequently cited as key problems for biomedical informatics. However, detailed accounts of what is meant by these terms are sparse in the literature. We argue for distinguishing two notions: ``size range,'' which deals with physical size, and ``collectivity,'' which deals with aggregations of individuals into collections, which have emergent properties and effects. We further distinguish these notions from ``specialisation,'' ``degree of detail,'' ``density,'' and ``connectivity.'' We argue that the notion of ``collectivity''--molecules in water, cells in tissues, people in crowds, stars in galaxies--has been neglected but is a key to representing biological notions, that it is a pervasive notion across size ranges--micro, macro, cosmological, etc.--and that it provides an account of a number of troublesome issues including the most important c...
Alan L. Rector, Jeremy Rogers, Thomas Bittner