Developmental assessment of infants and toddlers presents a host of clinical challenges, many of which are unique to this age range. These include determining whether the child has a delay or a deficit, selecting the proper assessment tools, and accurately interpreting the findings. This process has four components: administration of structured items, direct observations, caregiver report, and history. Clinical Vignette Jenny is a 2-year, 1-month-old toddler whose parents report continuing concerns about her development. Her pediatrician has responded with a request for a detailed developmental assessment. Language is a major area of worry, although motor skills are delayed, and Jenny is described as "clumsy." Jenny was born at 25 weeks gestational age. She spent her first 130 days after birth in the hospital. She had numerous health issues, including respiratory distress syndrome, intraventricular hemorrhage (IVH) Grade IV, and bronchopulmonary dysplasia (BPD). Jenny had Apgar scores of 3, 5, and 7 at 1, 5, and 10 minutes, respectively. An early intervention specialist screened Jenny at 18 months but found her to be ineligible for services because the magnitude of delay was not enough to warrant intervention. Sharing the parents' concerns, the pediatrician is now asking for more detailed assessment, observation, and measurement of the toddler's current functioning and development. What tests should you give to obtain critical information regarding Jenny's developmental status? Will the test findings provide insight with regard to what interventions are needed? What developmental problems might you expect, given Jenny's medical history? Clinical Challenges Prevalence of Developmental Problems Approximately 15% of the pediatric population has developmental problems. Of this subset, 45% have speech or language issues, 38% display developmental delay in other domains such as motor or adaptive skills, and 17% have autism or other disabilities (Feldman, 2020).