The Marschak Interaction Method (MIM) is a play-based, structured technique for observing and assessing the relationship between a parent/caregiver and child. It consists of a series of simple and fun tasks designed to elicit a range of behaviours in four dimensions: structure and challenge, engagement, nurture and playfulness. The MIM evaluates the parent or caregiver’s ability to set limits, engage the child through interaction while being attuned to the child’s needs, to meet the child’s needs for attention and soothing, and to support the child’s efforts to master developmentally appropriate tasks. Simultaneously, the method allows for assessment of the child’s ability to respond to the parent or caregiver’s efforts. The interaction is then coded by trained coders.