Towards a unified criteria model for usability evaluation in the context of open source software based on a fuzzy Delphi method

Abstract

A plethora of models are available for open-source software (OSS) usability evaluation. However, these models lack consensus between scholars as well as standard bodies on a specific set of usability evaluation criteria. Retaining irrelevant criteria and omitting essential ones will mislead the direction of the usability evaluation. This study introduces a three-step method to develop a usability evaluation model in the context of OSS. The fuzzy Delphi method has been employed to unify the usability evaluation criteria in the context of OSS. The first step in the method is the usability criteria analysis, which involves redefining and restructuring all collected usability criteria reported in the literature. The second step is fuzzy Delphi analysis, which includes the design and validates the fuzzy Delphi instrument and the utilisation of the fuzzy Delphi method to analyse the fuzziness consensus of experts' opinions on the usability evaluation criteria. The third step is the proposal of the OSS usability evaluation model. A total of 124 usability criteria were identified, redefined, and restructured by creating groups of related meaning criteria. The result of the groupings generated 11 main criteria; the findings of the fuzzy Delphi narrowed down the criteria to only seven. The final set of criteria was sent back to the panellists for reconsideration of their responses. The panellists verified that these criteria are suitable in the evaluation of the usability of OSS. The empirical analysis confirmed that the proposed evaluation model is acceptable in assessing the usability of OSS. Therefore, this model can be used as a reference metric for OSS usability evaluation which will have a practical benefit for the community in public and private organisations in helping the decision-maker to select the best OSS software package amongst the alternatives.