3.1.2. Inclusion and Exclusion Criteria in the Stage of Identification

According to [79], the preferred reporting items for systematic reviews include the stages of identification, screening, eligibility, and inclusion. In the first stage, namely, identification, five inclusion and exclusion criteria were established to guide the authors when gathering the relevant studies for this review. First, both the boxes of "include patents" and "include citations" were unchecked on the Google Scholar page. Patents were irrelevant to this academic study, while citations were found to be repetitive and challenging regarding finding online sources for further investigation.

Second, the "Advanced Search" setting of "Find Articles" was utilized. Articles with the *exact phrase* were identified and the selected keyword strings were keyed in, as mentioned earlier. The selection of "with *all* of the words," "with *at least one* of the words," and "*without* the words" were ignored, as the search results would be too general to review. Third, only the word occurring *in* the article title but not *anywhere* was identified. This selection also narrowed down the search results. Fourth, both the boxes of "return articles *authored* by" and "return articles *published* in" were ignored, with no limitation to authors and publishers.

Finally, the first box for the search period was left blank, with "2017" written down in the second box. Though the search period included up to December 2017, the authors did not set a specific limit for the beginning of the search period. Unlike [76–78], the initial search periods were set in 1992, 1993, and 1997, in line with the argument that these years appeared in the literature that is relevant to smart city concepts. Nonetheless, this study revealed that the topic of citizen centricity in smart cities was relatively discursive and multidisciplinary, with insufficient and reliable sources for an estimated period of two decades. Furthermore, the authors intended to acquire as many articles as possible to define the indicators. The detailed numbers of exclusion records in the first stage of identification are shown in Table 1.


**Table 1.** Records of patents and citations that were excluded in the identification stage (source: authors).
