Methodological justifications

¹ Nominal Group Technique (NGT) is a structured participatory technique promoting systematic idea generation and equal participation (Claxton et al., 1980). Widely applied in sustainability research (e.g. Hugé et al., 2023), it offers an effective alternative to focus groups for fostering diverse ideas, reflection, and peer learning (Ko de Ruyter, 1996)

² Facebook (FB) served as a digital ethnographic space, capturing organic, lived sustainability experiences in a way that traditional in-person observations could not (Hine, 2020)

³ Digital diaries capture real-time records of participants’ practices, reducing reliance on memory and minimising recall bias, allowing us to capture subtle aspects of practice performance not observable through direct research (Lovett and Peres, 2018)

⁴ Participant observation allows deeper contextual insights by witnessing practices as they unfold (Kozinets, 2019) while fostering rapport and positioning participants as equal partners in the data-gathering process

⁵ Introspection enables researchers to critically reflect on their own experiences, identifying challenges and emotions that may resonate with participants and thereby strengthening rapport and interpretation (Wallendorf and Brucks, 1993)

⁶ Online interviews offered flexibility, allowing participants to reference their FB posts in real time. However, limited visibility of household environments and non-verbal cues restricted contextual insights

⁷ The post-study interview was essential for capturing participants’ reflections on their engagement, challenges, and motivations, providing insights into how they navigated sustainability practices during the campaign