Comparing a forced-choice wug test and a naturalness rating test: an exploration using rendaku

• Experimentation is now common in linguistics.
• What kind of experimentation is best suited for phonological research?
• This study compared two studies on rendaku and Lyman's Law.
• A forced-choice wug test format is more reliable than a naturalness judgment task.
• Task effects in phonological experiments should be tested more extensively.

A growing body of linguistic studies is now deploying judgment experiments to probe both syntactic and phonological knowledge. Thus a research question arises as to what kind of judgment format is useful for probing our linguistic knowledge. Against this theoretical background, this study compares two types of phonological judgment experimentation: a scale-based naturalness judgment task and a forced-choice wug test. The current analysis uses the data from two previously published studies on rendaku, a famous voicing phenomenon found in Japanese compound formation, and Lyman's Law, which is known to inhibit rendaku. Although the two tasks at first sight show a close correlation with each other, a detailed examination of the data shows that the forced-choice wug-test reveals the influence of Lyman's Law on rendaku more clearly than the naturalness judgment experiment. To the extent that the effect of Lyman's Law is real, the current comparison shows that a forced-choice wug experiment is better than a naturalness judgment experiment. While the impact of the current results is limited and modest, this study provides a first step toward understanding how different tasks in phonological experimentation may compare to one another. It is hoped that the current study will plant a seed for a research program which addresses which kind of phonological judgment experimentation is best-suited to reveal our phonological knowledge.