Quality of Life Research

, Volume 22, Issue 8, pp 2005–2007 | Cite as

Commentary on “A new indicator for the measurement of change with ordinal scores”

  • Aaron Yarlas

The paper by Ferreira et al. [1] introduces a new statistic—the Indicator of Positive Change (IpC)—that evaluates, at the group-level, improvement on an ordinal rating scale following some intervention. As the authors point out, it is not uncommon to see distributional assumptions from interval or ratio scales improperly applied to ordinal scale data. Misapplying these assumption leads to the use of inappropriate statistical procedures for analysis of ordinal scale data, which often results in inaccurate and unwarranted interpretations. The IpC is proposed as a new approach for calculating a standardized statistic that captures the magnitude of group-level improvement on an ordinal scale measure without reliance upon distributional assumptions, which would avoiding these common problems.

Unfortunately, despite the authors’ claims, the calculation of the IpC does, in fact, incorporate unwarranted non-ordinal assumptions about the scale being evaluated, specifically the assumption of...


Ordinal Scale Distributional Assumption Ratio Scale Ordinal Outcome Ordinal Score 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Ferreira, M. L. P., Almeida, R. M. V. R., & Luiz, R. R. (2013). A new indicator for the measurement of change with ordinal scores. Quality of Life Research,. doi: 10.1007/s11136-012-0288-2.Google Scholar
  2. 2.
    Stevens, S. S. (1946). On the theory of scales of measurement. Science, 103, 677–680.CrossRefGoogle Scholar
  3. 3.
    Sonn, U., & Svensson, E. (1997). Measures of individual and group changes in ordered categorical data: application to the ADL staircase. Scandinavian Journal of Rehabilitation Medicine, 29, 233–242.PubMedGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2013

Authors and Affiliations

  1. 1.OptumLincolnUSA

Personalised recommendations