Three-item statements analysis

This idea is clearly embedded, but not particularly elaborated, by Nelson and Platnick (1981) in the sense that ancestors, whether taxa or characters, appear to be based on the absence of evidence. All cladists agree that cladistics is about grouping by synapomorphy and that synapomorphy is evidence of relationship. Three-item statements analysis codes data in the sense that taxon and homology represent the same relationship (Nelson and Ladiges, 1994), and unlike all other methods, it focuses on the smallest possible unit of relationship, the three-item statement, and then finds the tree to accommodate the most statements (Nelson and Ladiges, 1991d, 1994,1995). Viewed this way, three-item statements analysis shows an entirely different appreciation of data and accordingly, it improves the precision of parsimony (Nelson and Platnick, 1991 Morrone and Carpenter, 1994). 

Williams, D.M., Three-item statements analysis, in Cladistics The Theory and Practice of Parsimony Analysis, 2nd ed., Kitching, I.J., Forey, P.L., Flumphries, C.J. and Williams, D.M., Systematics Association Publication 11, Oxford University Press, Oxford, 1998, pp. 168-186. 

This approach to the understanding of homology has recently been implemented using parsimony analysis of three-item statements (Nelson and Platnick, 1991 Nelson, 1996 Kitching et al., 1998). This has been mistakenly considered to be simply a method of analysis, and criticism has so far dwelt only on technical matters. Little has been said about the possibilities offered by specifying statements of relationship, the problems presented by... 

Like other assessment instillments, the QLS was developed using patient interviews and factor analysis to derive those dimensions and questions that are most relevant to the patient s experience (Heinrichs et al., 1984). The QLS scale contains 21 items and is intended to be administered as a semi-structured interview. Each item consists of three parts a brief statement is provided to help the interviewee understand and focus on the parameter to be assessed a number of suggested questions are provided that may help the interviewer begin his exploration with the subject and a seven-point scale is provided for each item, with a brief description at four points to help the interviewee make... 

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