A great image “Four types of evidence” appears in a recent paper on probabalistic argumentation schemes ((‘Dempster-Shafer Argument Schemes‘ by Yuqing Tang, Nir Oren, Simon Parsons, and Katia Sycara (2013) in Proceedings of ArgMAS 2013.)). The delineation of 4 types of evidence ((These, the authors mention, were drawn from an earlier technical report: K. Stentz and S. Ferson. Combination of evidence in Dempster-Shafer theory. Technical Report SAND 2002-0835, Sandia National Laboratories, 2002. See especially pages 10-13. The context in that technical report, is sensor fusion using Dempster-Shafer Theory, which as I have since learned, is a common approach to combination of evidence.)) serves the larger goal of the paper — which is to describe how to combine evidence of different types.
The four types of evidence depicted are:
- Consonant Evidence – each set is wholly contained in another (all sets can be arranged in a nested series of subsets)
- Consistent Evidence – have a common element (nonempty intersection of all sets)
- Disjoint Evidence – in which there is no overlap (pairwise disjoint intersection of sets)
- Arbitrary Evidence – where none of the three preceding situations holds (i.e. there is no consensus but some agreement)
Evidence classification could possibly be thought of in conjunction with argument classification; for the latter, see my earlier musings Towards a Catalog of Argumentation Patterns.