The parent-child interaction strongly influences the emotional, behavioural, and cognitive development of young children. The nature of parent-child interactions differs in families with children with autism spectrum disorder (ASD), but research still entails a lot of inconsistencies and there is no consensus as to how these interactions should be coded. The parent-child interaction between sixteen mothers and their child with ASD (M age = 68 months) and a younger sibling without ASD (M age = 48 months) in a within-family study were coded using both a global and frequency coding scheme. Global and frequency codes of the same sample were compared to explore the value of each coding method and how they could complement each other. In addition, each coding method’s ability to detect group differences was evaluated. We found that mothers used an interaction style characterized by more support and structure, and clearer instructions in interaction with their children without ASD. In addition, global rating results suggested that within the ASD group, mothers may adapt their behaviour to the specific abilities of their child. Regarding the evaluation of coding method, results showed overlap between conceptually similar constructs included in both coding schemes. Although frequency coding clearly has its value, more qualitative aspects of the interaction were better captured by global rating scales and global rating was more time efficient. For this purpose, global ratings might be preferable over frequency coding.