Final answer:
A QDDP can determine if plans/active treatments are working by monitoring the progress of the individual and using data collection methods to assess the effectiveness of the interventions.
Step-by-step explanation:
One very important way a QDDP (Qualified Developmental Disability Professional) can determine if plans/active treatments are working is by monitoring and assessing the progress of the individual receiving services. This can be done through regular evaluations and observations to measure the effectiveness of the interventions. For example, if a QDDP is working with an individual with developmental disabilities who is receiving behavioral supports, they may use data collection methods, such as tracking the occurrence of challenging behaviors or assessing the individual's ability to use new skills, to determine if the treatments are resulting in positive outcomes.