How might one use an IGDI to monitor individual child progress?

In the same way that the pediatrician plots growth in a child's height and weight during each well-child visit every 3 months or so, an IGDI can be used to track a child's progress acquiring key skills. In assessing early communication using an IGDI, the child is engaged in a 6-minute play session by a familiar adult using a standard toy item like a house or barn, and the number of communicative behaviors produced by the child are counted and recorded. Charting growth in these communicative behaviors provides information on the child's rate of growth over time. This rate can be compared to normative expectation, falling above, at, or below age expectation, and this rate can be forecasted ahead to predict future performance three months or six months into the future. Thus, questions about acceptable progress or inadequate progress can be addressed, and interventions developed and implemented for those children whose rate of growth needs acceleration. For children whose growth and development are not acceptable, interventions can be implemented along with more frequent assessments (i.e., every other week or monthly), to reflect the immediate effects of the intervention and to inform subsequent decisions about intervention effectiveness.