Final answer:
Norms are useful for estimating how well a child's sounds are developing by providing average ages when most children reach specific language developmental milestones, but they should be used as general guidelines and not rigid expectations.
Step-by-step explanation:
The question pertains to how norms are used in assessing the development of a child's sounds or language skills. Normative approaches to development utilize norms, or average ages, to establish when the majority of children typically reach specific developmental milestones across physical, cognitive, and psychosocial domains.
Professionals can use these benchmarks to gauge whether a child’s development is on track with their peers. For example, while the norm for walking might be around 12 months, some children may walk earlier or later, and such variations can often be within normal limits. In this respect, norms are useful tools for estimating how well a child's sounds are developing but must be understood within the context of each child's unique developmental trajectory and cultural background.
Norms are derived from empirical studies that measure the abilities of a large sample of children at various ages. These norms are averages and should not be seen as prescriptive milestones every child must meet at a particular age. They provide a general guideline that can be helpful for comparing children with their same-age peers. This comparison offers a reference point rather than a definitive measure of development.