In order to better evaluate bilingualism in deaf children, this study examined whether observers (N=37) from different backgrounds would agree on deaf children's use of either American Sign Language (ASL) or English signing. Observers represented a range of background experience in a variety of schools and programs; 6 were deaf; 31 were hearing; 10 identified themselves as primarily ASL signers; and 27 as primarily Pidgin Sign English users. Observers viewed a videotape and decided whether the child signer was using ASL or English signing. Judgments were compared to those of a panel of sign language specialists. General results indicated no significant differences among observers at different levels of experience nor between deaf and hearing observers. However, the average score of deaf observers was significantly higher than that of hearing observers in identifying one child using ASL. Observers made their judgments predominantly on the basis of language use rather than structure or content. Results suggest that professionals working with deaf children cannot reliably distinguish between ASL and English signing and that years of experience with the deaf or being deaf oneself was of minimal assistance. Continued study of differences and similarities in ASL and English signing is recommended. Includes 29 references. (DB)