# Improving User Experience with Recommender Systems by
## 5 Discussion and Conclusions
### Limitations and Opportunities for Future Research  
Despite the scenario used in this study and the validation of the two levels of situational complexity through a manipulation check prior to their use, situational complexity was not found to have any effects on either user beliefs or behaviors. This was an unexpected finding as the factor and its two levels were tested through two rounds of manipulation checks involving (i) nine participants prior to the start of this study, who reported unanimously that the high-complexity situation was indeed more complex than the low-complexity situation based on the information presented in the recommendation messages, and (ii) thirty participants responding to the question \"How challenging was the situation you were faced with?\" (simple = 1... 5 = complex). It is plausible that while the high-complexity stimuli were indeed significantly higher in complexity than the low-complexity stimuli, given the brevity of the messages, the complexity was not sufficiently high to induce significantly higher levels of cognitive load (and by extension, time needed), more negative emotions (either valence or arousal), and/or worse beliefs and attitudes. Another possible explanation for the insignificance of situational complexity could be the likely lack of domain knowledge on the side of participants. Nuances in complexity of messages pertaining to product perishability and ease of product storage might require knowledge that is likely to be unique to those with significant experience in the restaurant or catering industry. Hence, we have two sets of recommendations for future research. First, future research could focus on assessing situational complexity where the role of domain-specific knowledge might be less significant. Second, future research that aims to inform RS design according to situational complexity should first explore for situational complexity 'thresholds', above which effects are observed in regard to users' cognition, emotion, or behavior, and design stimuli accordingly. While this study undertook an investigation of an extended research model, observing the variance extracted from the mediating and dependent variables, additional explorations of the effects of additional factors on message- and system-level outcomes are needed. Other factors that can be identified in the literature and could be tested in future studies include message detail, message length, the use of subjective versus objective language, personification, affective language use, personality, and vague language [16; 62; 63; 64; 65; 66; 67; 68]. Building upon results from this experiment, future work should also involve triangulated attentional and physiological measurements to gain a richer understanding of the mechanisms at play. Using eye fixation-related potential [69], future research could explore the cognitive mechanism involved in user decision making at the moment of the recommendation's consideration. Lastly, future research should explore potential interactions between message characteristics, e.g., revisiting situational complexity, such user perceptions may in fact be the outcomes of interactions with specificity and information sequence as they are inherently dimensions that add to or reduce message complexity, revealing that situational complexity may be a second-order construct comprised of various message characteristics that add to complexity. Finally, an extended study could also be performed with the three significant factors used here (i.e., problem information specificity,solution information specificity, and information sequence) to find the best combination for the optimal presentation of recommendation messages. Conceptualization and methodology, all authors; writing--original draft preparation, A.F. and C.K.C. ; writing--review and editing, J.B., W.V.O., S.S. and P.-M.L. ; supervision, C.K.C. and P.-M.L. ; funding acquisition, C.K.C. and P.-M.L. All authors have read and agreed to the published version of the manuscript.