Does tone matter? Exploring context-aware explanations in route recommendations

Recommendation algorithms support decision-making, yet their reasoning is often opaque. Explanations can improve user understanding, but the role of tone has received little attention, particularly in relation to situational context. This is especially relevant for route recommendations, where factors such as urgency shape travellers' needs. Using a mixed-method approach (focus groups, n = 15; validation study, n = 32; online experiment, n = 150), we examine how tone is perceived across contextual conditions in public transport. Unlike prior work comparing tone across domains and users, we focus on within-domain, situational context-dependent effects. Results show that situational context affects tone preferences. In urgent situations, humorous and empathetic tones are less appreciated than neutral or authoritative ones, and some tones are more context-sensitive than others. Our findings emphasise considering situational context when designing recommendation explanations, and offer guidance for designers and researchers.