## 2 Methodology
### Instrument  
The assessment scales that were used in our study were developed based on previous research on the educational use of a videoconferencing tool by the authors [44] and were also partly evaluated using two small convenience samples in an earlier pilot study on the use of Bing Chat for learning activities in higher education [45]. The survey that was used in our study consisted of demographic questions and questions related to respondents' previous use of LLMs and other AI-based systems like ChatGPT and GPT-4, as well as of assessment scales (with 4-7 items each) that were constructed to measure the variables associated with students' perceptions of usability and user experience characteristics of Bing Chat. The participants responded to each of the items in the assessment scales using the following 1-5 Likert-type scale: \"1--I totally disagree\"; \"2--I disagree\"; \"3--I neither agree nor disagree\"; \"4--I agree\"; \"5--I totally agree\". The variables (constructs) for which the assessment scales were developed are briefly explained (with the number of items and a sample item in brackets) in the continuation of this section. The complete assessment scales with all of their items can be found in the Appendix A. _Perceived Usefulness_ is a construct introduced in 1989 by [PERSON] [26] as one of the main variables of the Technology Acceptance Model (TAM), and as mentioned earlier, is frequently found in contemporary research that uses TAM/UTAUT as a theoretical background (5 items; an example item: \"I have determined that I can make good use of Bing Chat.\"). _General Usability_ is a construct related to the System Usability Scale (SUS) [46], a popular instrument for the measurement of perceived usability that was developed by [PERSON] in 1986. However, the structure of SUS comprises both usability and learnability [47], while in our study, this scale is used to specifically measure general usability. It must be noted that this scale is still very popular with numerous recently published studies that report its use for the evaluation of diverse technologies in various environments, including higher education, for instance, (a) concerning the use of the chat application _Differ_ for communication with students [48], as well as (b) the evaluation of text generation by ChatGPT [49] (5 items; a sample item: \"Bing Chat responds to my queries/commands as I expect it to.\"). _Learnability_ is often considered an important component of the usability of technological systems and is also one of the two factors measured by the widely used System Usability Scale [46]. For instance, in educational settings, it was a component of usability that was investigated concerning the Blackboard learning management system [50] (5 items; representative item: \"One can quickly learn the basics of working with the Bing Chat tool.\"). _System Reliability_ is one of the components of the DeLone and McLean Information System Success Model (ISSM) [29; 30] and an important aspect of information system quality (4 items; illustrative item: \"Bing Chat worked fast enough and reliably.\"). _Visual Design and Navigation_ is a construct related to the attributes of computerized display of information, which was first mentioned in the scholarly literature about hypertext (see: [51]). It must be noted that the components of visual design and navigation are interlinked, ensuring both usability and the desired user experience of websites [52] (6 items; exemplary item: \"Functionalities on the Bing Chat interface are well organized and easily accessible, e.g., menus, copying, etc.\"). _Information Quality_, as a component of the DeLone and McLean ISSM [29; 30], commonly includes attributes like [53]: accuracy, relevance, timeliness, understandability, completeness, and usefulness (6 items; sample item: \"The use of the Bing Chat service enabled the collection of accurate information.\").