Purpose: This paper aims to investigate small-scale, qualitative observations of interviewer-respondent interaction in the Organisation for Economic Co-operation and Development's Programme for the International Assessment of Adult Competencies (PIAAC). Design/methodology/approach: The paper uses video-ethnographic methods to document talk and gesture in assessment in Slovenian household settings. It presents an in-depth case study of interaction in a single testing situation. Findings: Observing interaction in assessment captures data on assessment performance that is not available in quantitative analysis of assessment response processes. The character of interviewer-respondent interaction and rapport is shaped by the cognitive demands of assessment and the distinctive ecological setting of the household. Research limitations/implications: Observational data on assessment response processes and interaction in real-life assessments can be integrated into and synthesized with other sources of "process data". Practical implications: Assessment programs such as PIAAC should consider the significance of the household setting on assessment quality and observations of interaction in assessment as a valid source of paradata. Social implications: There is a place for small-scale observational studies of assessment to inform public understanding of assessment quality and validity. Originality/value: The paper provides qualitative insights into the significance of interaction and "interviewer effects" in household assessment settings.