“…In previous research and papers on HPO, which we have published in the past years, we have already used the HPO definition as developed and proposed in this article. Other researchers have come across our proposed HPO definition and it seems to have struck a chord with them, possibly because they were also looking for an adequate definition, as an increasing number of them are using the proposed HPO definition and measurements in their own research (Abdullah et al , 2018; Do and Mai, 2020; Geleta, 2019; Hijal-Moghrabi et al , 2017; Honyenuga and Tuninga, 2013; Honyenuga et al , 2019; Kalimullah et al , 2019; Roijen et al , 2017; Thoman and Lloyd, 2018; Zbierowski, 2020).…”