It is well-known that extraction out of indefinite NPs is allowed while the
definite NPs behave like syntactic islands. Moreover, although superlative
NPs in English (e.g. the smallest photo of Einstein) contain the definite
article, they pattern with indefinite NPs regarding extraction (Szabolcsi
1986). This claim has not been verified by experimental methods. The
purpose of the current study is two-fold: 1. use factorial design to verify
the status of this island effect (see also Keller 2000, Tollan & Heller
2015, Neal & Dillon 2021); 2. experimentally compare superlative NPs with
definite and indefinite NPs in terms of their islandhood.