Contact diary had been used since the 1960s (e.g. Gurevich) and continued with greater vigour from the 1970s (e.g. Pool and Cohen, Freeman and Thompson, Lonkila). Initial attempts mainly aimed to estimate the extent of the personal network surrounding an individual.

Since the mid-2000s, Fu's (2005, 2007, 2008) work has given a new impetus to the use of the contact diary method. In Hungary, the first diary data collection was carried out a few years later, in 2010, on an experimental basis. In terms of duration, different tools had been developed and implemented. In this presentation, we introduce the one-week contact diary and the strength of ties (SoT) index developed on this basis, we discuss the two-days diary tool and the operationalization of the strength of ties based Granovetter’s idea. We demonstrate the successful implication of the one-day diary during the pandemic. In the presentation, we will argue for the advantages of the contact diary, highlight its potential as well as discuss the method’s weaknesses and challenges.

Over the past two decades, contact diary studies have gained increasing interest, primarily relying on a quantitative perspective that focuses on statistical analysis. We employed a mixed-methods approach to understand how high school students used a smartphone application to record contact diaries. This approach allowed us to capture adolescents' interpersonal interactions, the quality of these interactions, as well as their emotions and perceived benefits following the interactions. A total of 46 participants (egos) were enrolled in the study. All of these students recorded diaries for 30 days, yielding a total of 25,608 contacts with 1,846 individuals (alters). This paper discusses the findings derived from in-depth interviews conducted with these students and reveals the core values of their participation as follows:

1. Keeping diaries reduces stress, reveals emotional changes, and helps students understand relationship patterns and social dynamics.

2. Reflecting on diary content provides deeper insights into social networks, fostering personal growth.

3. Families offer material support and companionship, while peers contribute to leisure and academic knowledge through interactions, enhancing both social and academic learning.

4. By keeping contact diaries, students can better understand how they manage their time, enabling them to plan their schedules more effectively.

Specifically, by recording reflections in contact diaries, high school students can better understand their thoughts and feelings. The contact diary study, as a methodology, effectively captured the realities of adolescents’ lives, encouraged them to reflect on their experiences, and enhanced their awareness of interpersonal networks. Finally, we discussed the evaluation criteria for contact diaries.

Mood and stress states dynamically shape social interaction patterns, influencing both the motivation to seek contact and the likelihood of social integration. Positive mood fosters open body language, thereby enhancing perceived social attractiveness, and strengthens relational bonds, whereas negative affect—such as stress and anxiety—can trigger social withdrawal or the seeking of social support as a coping mechanism. However, empirical evidence on how momentary affective states and physiological stress responses impact the formation and dissolution of social ties remains scarce.

This study leverages ecological momentary assessment (EMA) data from the Peer-Smart Network Study, a longitudinal whole-network dataset capturing real-world interactions among 50 university students in Germany. Over seven consecutive days, participants completed three daily contact diaries, reporting social interactions within their predefined cohort network. Emotional and instrumental support exchanges, as well as negative interactions, were systematically recorded. Momentary mood and emotional stress were assessed through short surveys, while continuous physiological stress markers were collected via Fitbit wearables, capturing heart rate, sleep quality, and physical activity patterns.

Using relational event models, I examine how fluctuations in mood and biosignals for stress influence personal contact ties, as well as the provision and reception of social support. The findings contribute to theories of affective social integration and advance methodological approaches by combining self-reported network data with passive sensor data collection.