## 5 Discussion
### Discussion Research Objective One: Design of Open-Text Items for Assessing \"Selecting dLMs\"  
Regarding research question 1.1, the proposed approach is characterized by a suitable process since the items' operationalization and coding procedures are documented intersubjectively and comprehensibly. In addition, standardized online tests were used to capture the data consistently. The results of the inter-rater agreement indicated the objectivity of the coding and scoring. The reliability of the four-item instrument, as measured by [PERSON]'s \(\alpha\), was good (Study 1). A critical question is whether using [PERSON]'s \(\alpha\) to assess the reliability of the instrument is justified, given that the same items were used, albeit in different contexts (dLM1-dLM4). Other approaches, such as developing different items, retesting at different times, or using the existing items in more different contexts, as demonstrated in one of the pilot and interview studies we conducted [9; 63], are alternatives. However, the latter approaches carry other risks, as the reasoning for \"selecting dLMs\" may differ from the reasoning for selecting digital technology or the knowledge that test participants acquire over time. The variation of the dLMs used in this study presents sufficiently different contexts using the same four items to assess \"selecting dLMs\"; however, the high [PERSON]'s \(\alpha\) values may be explained by using the same items [72]. Participants in Studies 1 and 2 applied similar reasoning for dLM1 (research question 2.3), which further evidences reliability, despite the differing structure of the participant pool in both studies. The validity of the four-item instrument is theoretically supported by the frameworks used in its conceptualization, namely the TPACK framework [16] and the competence model by [PERSON] et al. [34]. In addition, the European DigCompEdu [44] and [PERSON]'s Anglo-American teacher practices [45] are utilized to establish the TCK, TPK, and TPACK reasoning model (see Figure 2 and Table 1). Moreover, involving peers, teacher educators, and in-service teachers in the genesis of the items and the smaller quantitative pilot [62; 63] and the qualitative interview study [9] further substantiated the approach and its validity. Figure 4: Proportions of no, generic, single TCK-x, TPK-x, and multiple TCK-x/TPK-x and TPACK reasoning used to justify the selection of dLM1 [65] in Study 2. Whether the four-item instrument assesses competence, particularly the competence facet of \"selecting dLMs\", we concur with the findings of [PERSON] and [PERSON] [43] that the instrument assesses something along the continuum of dispositional knowledge and competence, as articulated in the model by [PERSON] et al. [34]. Items (1-3) assess dispositional knowledge, and item 4 evaluates the interpretation and perception of the dLM regarding its suitability for learning content, learner age, and the special needs of learners, and thus competence. But does the four-item instrument capture TPACK? The literature and conceptualization support the notion that the instrument captures TCK, TPK, and thus TPACK reasoning. For obvious reasons, reasoning using just one TCK-x and TPK-x reason, hence TPACK reasoning, does not encompass TPACK in its entirety. Even if we were to expand the scoring, as established in Figure 2, so that all TCK-x and TPK-x reasons (Table 1) were required to obtain the maximum score, one could still argue it is only in the context of a single dLM and thus remains limited. However, similar limitations apply to other assessments, such as evaluating (fictitious) lesson plans, which also have a restricted scope. The study by [PERSON] et al. [73] cites three to ten selection opportunities for a lesson plan and four to eighteen justifications. The latter equates to an average of two justifications per selection, the same number of reasoning considered in our scoring as the maximum (see Figure 2).