## 3 Materials and Methods
#### Systematic Literature Review Process  
Different combinations of keywords were used to find the most relevant documents. The final query used consisted of a combination of keywords relevant to the main topics explored in this study and was as follows: \"(\"augmented reality\" OR \"virtual reality\" OR \"extended reality\" OR \"mixed reality\" OR \"metaverse\" OR \"ar\" OR \"vr\" OR \"mr\") AND (\"learning analytics\" OR \"educational data mining\" OR \"edm\"). This query was selected as it yielded the most relevant documents. Although the abbreviations can identify additional related documents, their use also results in the identification of documents that are not related to the topic. For example, \"mr\" and \"edm\" are also acronyms for different things besides mixed reality and educational data mining. However, it was deemed more appropriate to be included not to miss any related document. Hence, a large volume of documents was omitted during the initial screening. Additionally, the search query did not have any limitations regarding the year of publication and publication type. However, only English documents were considered and examined in this study. The relevant documents were searched on a topic level, namely the document title, document abstract, and document keywords.  
The final search was performed in December 2024 and resulted in the identification of 773 documents. Specifically, 404 documents returned from Scopus, 184 from WoS, 102 from IEEE, 37 from ScienceDirect, 22 from ERIC, and 19 from ACM. Given that most highly regarded outlets are indexed in a combination of these databases, 259 documents emerged as duplicates based on their title and were removed. Throughout the process of assessing the eligibility of the documents, the authors worked independently and cross-checked their results. In the cases where there was a different outcome, the related document was further discussed. The values reported reflect the final outcomes of the procedure. Therefore, 514 documents were then screened manually according to their title and abstract for eligibility. For a study to be included in this review, 4 inclusion criteria were set and had to be met. Specifically, the study had to (i) involve extended reality technologies; (ii) involve educational data mining and learning analytics methods; (iii) focus on or be applied in educational settings; and (vi) focus on the combination of learning analytics and/or educational data mining with extended reality technologies. Hence, only studies that met these inclusion criteria were included in the document collection.  
Through the initial screening, 422 documents were omitted since they did not satisfy the inclusion criteria. This number can be justified based on the strict criteria set, as well as the use of multiple abbreviations within the search query. However, we deemed that it would be better to eliminate more documents that are not suitable than miss some documents because abbreviations were not used in the search query. Hence, 92 documents remained and were sought for retrieval. Since all documents were retrieved, all potentially relevant documents were manually assessed for eligibility by examining the documents' full text. Taking the inclusion criteria into account, 22 more documents were excluded because they did not satisfy one or more of the criteria specified. Particularly, 14 documents were removed because they did not focus on the combination extended reality technologies with learning analytics and/or educational data mining, 3 documents were excluded because they did not involve educational settings, 3 documents were removed because they did not focus on educational data mining or learning analytics, and 2 documents were excluded as they were not related to extended reality technologies. As a result, 70 studies satisfied the criteria set and were included in the document collection examined. The complete process of document identification, processing, and selection, which followed the PRISMA framework, is showcased in Figure 2.