Classifier constructions are universal to sign languages and exhibit unique properties that arise from the nature of the visual-gestural modality. The major goals are to highlight critical issues related to the study of classifier constructions and to present state-of-the-art linguistic and psycholinguistic analyses of these constructions. It is hoped that by doing so, more researchers will be inspired to investigate the nature of classifier constructions across signed languages and further explore the unique aspects of these forms.