The present paper reviews the psycholinguistic dimensions of code-switching research and discusses the methodological issues when experimenting with code-switching, such as subjects, language modes, stimuli and tasks. Emphasis is put on the evaluation of the bilingual model of word recognition proposed by F. Grosjean and its explanatory power. The analyses show that this model can explain the effects such as activation states and homophones in bilingual modes, but does not point out the role of language nodes in bilingual processing.