Sander (1972) summarized normative data from many studies and identified the age at which 90% of all children produced each consonant correctly more often than not. This age for the group is referred to as the...

Sander (1972) summarized normative data from many studies and identified the age at which 90% of all children produced each consonant correctly more often than not. This age for the group is referred to as the...

• A. Age of mastery
• B. Median age of acquisition
• C. Age of customary production
• D. Normal limit of acquisition

Answer: (A)

In phonetic development, the term used for the age by which about 90% of children produce a consonant correctly is the age of mastery. Sander’s work pooled data from many studies to identify the point at which a sound has become reliably produced by the vast majority of children, not just a few. That 90% criterion signals a stable, typical achievement across the group, marking when the sound can be considered mastered for practical purposes in development. This differs from the median age of acquisition, which would indicate the age by which half of children have acquired the sound, a different threshold and not the same level of reliability. The other labels aren’t standard terms used to describe this 90% mastery criterion, so age of mastery best captures the concept described by Sander’s normative data.

In phonetic development, the term used for the age by which about 90% of children produce a consonant correctly is the age of mastery. Sander’s work pooled data from many studies to identify the point at which a sound has become reliably produced by the vast majority of children, not just a few. That 90% criterion signals a stable, typical achievement across the group, marking when the sound can be considered mastered for practical purposes in development.

This differs from the median age of acquisition, which would indicate the age by which half of children have acquired the sound, a different threshold and not the same level of reliability. The other labels aren’t standard terms used to describe this 90% mastery criterion, so age of mastery best captures the concept described by Sander’s normative data.