Background: The ability of descriptive assessments to differentiate functions of problem behaviours might be increased by systematically sampling natural contexts characterized by different establishing operations. This study evaluated the stability of such characteristics, and variability in challenging behaviour, for three school contexts. Method: A 10-year-old girl with severe intellectual disability and her carers were repeatedly observed in three situations hypothesized to vary in levels of demand and attention presented by carers. Results: Levels of demand and attention were stable within, and varied systematically between, contexts; however, characteristics of one situation were not as expected. Levels of problem behaviour were reliably higher in one context than in the other two. Conclusions: The demand and attention characteristics of two natural contexts were found to reliably resemble some antecedent conditions typically used in experimental functional analyses. Context sampling may improve the power of descriptive assessments to differentiate functions of problem behaviour.