Which example demonstrates within-class generalization after a training set for stopping fricatives (intermediate goal: stopping of fricatives; specific goal: /f/)?

• A. the child correctly articulates feather, field, knife, coffee on a generalization probe.
• B. the child's mother reports that he said I found four eggs correctly at a party.
• C. the SLP notices that the child is now producing /v/ sounds correctly some of the time.
• D. the SLP notices that the child is stimulable for /ɹ/ whereas he could not imitate this sound previously.

Answer: (C)

Within-class generalization means using what’s learned about one member of a sound class to improve performance on other members of that same class. In this case, the goal is stopping fricatives, with /f/ as the specific target. If the learner starts to produce another fricative, like /v/, correctly even after training on stopping fricatives, that shows the skill is spreading within the fricative class—not just improving on the exact sound practiced. Seeing /v/ produced correctly some of the time indicates this broader transfer within the class of sounds that share the fricative articulation category.

The other options don’t show that kind of spread across fricatives: producing /f/ in several words demonstrates generalization of the trained sound to new contexts, but not generalization to other fricatives; reporting on a different phrase or non-speech behavior doesn’t reflect the class-wide transfer; and stimulability for a different sound doesn’t indicate generalization within the fricative class.