New publication by Roger Watson

Roger Watson has co-authored:

Roger Watson

Watson R, Thompson DR, Wang W (2014) Violations of local stochastic independence exaggerate scalability in Mokken scaling analysis of the Chinese Mandarin SF-36 Health and Quality of Life Outcomes 12, 149 

Roger says of the study: In assessing the psychometric properties of measurement scales - whether by factor analysis or item response theory - it is essential that items behave as they do - either forming factors or scales - due to their response to what is being measured (ie the latent trait). This property is called local stochastic independence (LSA). LSA is hard to assess, especially in polytomous items and we fear that some of us may have seen Mokkken scales (Mokken scaling is non-parametric item response theory) where none exist due to the violation of LSA. We investigated this by comparing two subscales of the SF-36: one which clearly violated LSA and one which probably did not and found that the scalability properties of the one violating LSA were very high and probably exaggerated. We discuss the consequences of this in the article.

New PLOS One paper by Roger Watson

Professor Roger Watson has co-authored:

Roger Watson

Shenkin SD, Watson R, Laidlaw K, Starr JM, Deary IJ (2014)  The Attitudes to Ageing Questionnaire: Mokken Scaling Analysis PLOS One 9, e99100

Of the paper, Roger says: this was a collaboration with colleagues in Edinburgh and the data come from the Lothian Birth Cohort 1936 study which is producing a lot of interesting data about ageing and psychology.  The paper shows the value of applying alternative methods of analysis to large datasets; in this case, Mokken scaling revealed some new dimension to attitudes to ageing not seen using factor and Rasch analysis.

New publication by Roger Watson

Roger Watson has published:

Professor Roger Watson

Watson R, Thompson DR, Wang W, Meijer RR (2014) Investigating invariant item ordering in the Mental Health Inventory: an illustration of the use of different methods Personality and Individual Differences 66, 74-78
Of the paper Roger says: I am especially pleased to work with international colleagues from Australia, Singapore and The Netherlands; the paper makes a theoretical and a practical contribution regarding the concept of invariant item ordering in clinical assessment scales and also the application of Mokken scaling.