Cross-linguistic adaptations of The Comprehensive Aphasia Test: Challenges and solutions

Aphasia is characterized by extensive variation in degree and type of language impairment as well as in management strategies and impact on quality of life, both within and across speakers with aphasia and their families (Whitworth, Webster, and Howard, 2014). Thus, aphasia research and rehabilitation is heterogeneous and characterized by language-, region-, and discipline-specific features. Hence, comparison across borders (linguistic, regional or disciplinary) is often difficult or impossible to achieve. A particular obstacle to comparative research on aphasia and aphasia rehabilitation is the lack of comparable assessment tools across different languages. In English, there is a vast array of tools available, while in most other languages, the selection is scarce, and often the tools are not standardized and lack norms. As a first step in meeting the needs for comparable assessment tools across the languages of Europe and thus paving the way for more robust research on aphasia and aphasia rehabilitation, The Comprehensive Aphasia Test (CAT) (Swinburn, Porter, and Howard, 2005) is currently being adapted into 14 European languages belonging to a variety of language families: Basque, Catalan, Croatian, Finnish, French, Greek, Hungarian, Lithuanian, Norwegian, Portuguese, Serbian, Spanish, Swedish, and Turkish. This collaborative effort is carried out by members of COST Action IS 1208: "Collaboration of Aphasia Trialists". For each language, local, ideally interdisciplinary, working groups have been established, and the adaptation process is informed by guidelines that have been jointly established and agreed upon. Each language group follows a committee approach in the adaptation (Hambleton, 2005). Following the adaptation, each language version of the CAT will be standardized and normed based on a common set of instructions. The CAT consists of three parts: a cognitive part, a linguistic part, and a disability questionnaire. The test items in the linguistic part of the test battery are selected on the basis of a range of underlying variables, including phonological, semantic (e.g. imageability), syntactic, and usage based (e.g. frequency) ones. A key feature of the adaptation process is to ensure comparability across the various languages on the level of these underlying variables. Several of the languages involved lack the necessary background data on variables such as frequency and imageability. Hence, as part of the adaptation process these data have also been established. In our presentation, we will discuss some of the key challenges of adapting an existing aphasia test battery into several other languages, as well as the solutions we propose to ensure that the resulting assessment tools be linguistically and culturally equivalent.