In the recent decade, real-time comments in live video streaming and Danmaku in streaming media are gaining popularity and prevalence in many different systems as a type of novel comment feature that alters users’ virtual interactive experience and has a great impact on users’ holistic system usage. Regardless of whether the streaming is going live, they share a common key characteristic, which is to present comments simultaneously with the corresponding streaming context of their generation, so as to allow users to interact in the same specific situation. Therefore, these comments are conceptualized as situational comments (SC), and the systems incorporated situational comments are named as situational comments systems (SCS).

Various systems are attempting to leverage SC, but SC is not always beneficial to users’ system usage. Some preliminary studies have demonstrated the adverse effects of SC, in which users complain about unwanted comments and a great deal of SC that disturbs them (e.g., Chen et.al, 2015). Within a short period of time, we can observe a user get a very different impact from SC across different times of usage. Though in the same SCS use situation, different users may have different or even contrary experiences. There is significant dynamic variance in the impact of SC on system usage across situations and individuals. Regarding the salient dynamic variance in users’ SCS experience and behavior and the prevalence of SC in a variety of systems, a conundrum troubling a great many practitioners awaits investigation: when and how do situational comments enhance users' experience and bring benefits to their system use?

The conventional comment function has long been used across various systems to allow for users’ social interactions and opinion sharing, such as comments on social media, and consumer reviews on e-commerce platforms, which resemble the form of online communities. However, what situational comments enable is beyond an online community but a virtual collective situation (VCS), due to its essentially distinctive characteristics of temporality, situation embeddedness, and diversity. Situational comment interactions in VCSs are serendipitous along a communally ongoing streaming background and dynamic across different moments. Unlike online communities or social networking sites, peer interactions in a VCS do not necessarily maintain long-term or rely on connections among users. In the SCS use process, individual users are situated in flowing SCs and ongoing shared activity. In terms of the impact of SC on user system usage, it is largely determined by the match between users and the SCS-created situation during the interaction process. The individual situational interaction states (e.g., momentary focus and momentary emotion match), which are users’ momentary reactions to the SCS-created situation, are imperative to explain the dynamic impact of SC.

Extant literature about the effects of SC focuses on users’ general use of SCS and applies surveys or qualitative methods to collect subjects’ general psychological perceptions and general use of SCS. With the assumption that SCS usage is longitudinally stable, researchers have been trying to explain how SCS induces positive outcomes, by focusing on long-term factors such as group identification (Hu et al., 2017), sense of community (Hamilton et al., 2014), attitude (Chen & Lin 2018), perceived value (Chen & Lin 2018), platform attachment (Li & Cai 2021), and satisfaction (Wang & Li, 2018). However, constrained by the assumption, the existing studies fail to capture or explain the dynamic variance of SCS experience and usage. Furthermore, there is a lack of understanding about how the IT capacities of situational comment systems can help users mitigate annoyance and promote the benefits of situational comments.

To investigate the above-mentioned problems, this dissertation takes a virtual collective situation perspective and draws on Interaction Ritual Theory to propose that transient situational interaction states (i.e., virtual emotional entrainment and virtual mutual focus) and their two instant positive outcomes (i.e., emotional energy and solidarity) are the impactful antecedents to users’ retention in one SCS usage. This study complements previous literature that mainly focuses on long-term factors such as attitude, habit, and group identification, by offering more nuanced insights in terms of usage time frame. Furthermore, two IT capabilities of SCS (i.e., dislike-focus personalization and activity-comment priority) are theorized, and their effects are tested on two critical situational interaction states. A 2×3 factorial experiment was conducted online to empirically test the hypotheses. Most hypotheses get supported.