subjective-test 0.0.2

Transforming the Mean Opinion Scores (MOS) values given their 95% Confidence Intervals to safely use rank based statictial techniques.

MOS-transformation

Implementation of MOS-transformation to be used with Rank based statistical techniques.

The rank correlation coefficients and the ranked-based statistical tests (as a subset of non-parametric techniques) might be misleading when they are applied to subjectively collected opinion scores. Those techniques assume that the data is measured at least at an ordinal level and define a sequence of scores to represent a tied rank when they have precisely an equal numeric value.

In this paper, we show that the definition of tied rank, as mentioned above, is not suitable for Mean Opinion Scores (MOS) and might be misleading conclusions of rank-based statistical techniques. Furthermore, we introduce a method to overcome this issue by transforming the MOS values considering their 95% Confidence Intervals. The rank correlation coefficients and ranked-based statistical tests can then be safely applied to the transformed values. We also provide open-source software packages in different programming languages to utilize the application of our transformation method in the quality of experience domain.

Code

How to use?

    mos = [10, 6, 5.5]
    ci = [4, 2, 0.2]
    t = transform_mos(mos, ci)
    #  expected_rank = [3, 1.5, 1.5]

Contact

Babak Naderi, babak.naderi[at]tu-berlin.de

Citation

Naderi B, Moeller S. Transformation of Mean Opinion Scores to AvoidMisleading of Ranked based Statistical Techniques 2020 Twelfth International Workshop on Quality of Multimedia Experience (QoMEX). IEEE, 2020.

License

MIT License

Copyright 2020 (c) Dr. Babak Naderi.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.