AbstractBackgroundPeer support has a key role to play in national and local health services worldwide given growing need, pressure on resources, and strategic drives towards supporting people to manage their own health. Yet evaluation of peer‐only and multi‐component peer and professional group services is held back by research methodology gaps, including the absence of direct, within‐session evaluation tools. The current study evaluates the relationship between participation and conversational characteristics using linguistic analysis of a series of online bereaved support groups.MethodParticipants were bereaved family caregivers (N = 102) attending Rare Dementia Support bereaved support group meetings between March 2017 and March 2022. Attendance rates and (virtual) travel distance were compared for in person meetings (N = 9 sessions; 2017‐2019) and online meetings (N = 26 sessions; 2020‐2022). During each online session, notable phrases & contributions were recorded using a verbatim note‐making process and shared with participants post‐session as a reminder of the experiences shared by group members. These text files (660 phrases comprised of 9,600 words) were analysed using Linguistic Inquiry and Word Count (LIWC; Pennebaker et al., 2015) software, automatically classifying words into LIWC categories of analytical thinking, clout, authenticity and affect variables.ResultThe switch to online sessions increased accessibility to bereaved support in terms of attendance rates (Figure 1A), geographical proximity (Figure 1B) and group consistency (Figure 1C, e.g. higher proportion of online attendees returned for further sessions [in person 42%, online 69%; McNemar χ2 = 3.84, p = 0.0001]). Linear regression analyses with robust standard errors revealed that greater session attendance (mean number of sessions attended by participants present) was associated with conversations that were more authentic and less emotional and definitive (i.e. more reflective) over time (regression coefficients: Authentic: 0.111 [0.073, 0.149]; Affect: ‐0.637 [‐1.089, ‐0.185]; Clout: ‐0.066 [‐0.112, ‐0.020]; see Figures 2A‐C). The level of analytical thinking was maintained across sessions (Analytic: ‐0.012 [‐0.086, 0.061]; see Figure 2D).ConclusionOnline peer groups offer a practical and effective medium for bereavement support. Shifting the focus of evaluation to the processes of social support – how it is delivered and received – rather than just the outcomes, offers insights into the mechanisms of peer support.