The Test of English as a Foreign Language (TOEFL) is intended to assess the ability of nonnative speakers to understand spoken English, to comprehend reading materials, and to recognize correct structural, grammatical, and lexical usage. Responses on the TOEFL may reflect both the influence of the examinees' native language and their level of English proficiency. Unlike previous research, this study appraised the influence of examinees' native language and level of English proficiency on the structure of the TOEFL. More specifically, it aimed to assess the interrelations among TOEFL items for groups of examinees that systematically varied in native language and level of English proficiency, going beyond the usual right versus wrong scoring to use all the information provided by the various responses to the items.