Towards a quantitative measure of verbal effectiveness and efficiency in the Amsterdam-Nijmegen Everyday Language Test (ANELT)

Abstract

Background: A well-known test for measuring verbal adequacy (i.e., verbal effectiveness) in mildly impaired aphasic speakers is the Amsterdam-Nijmegen Everyday Language Test (ANELT; Blomert, Koster, & Kean, 1995). Aphasia therapy practitioners score verbal adequacy qualitatively when they administer the ANELT to their aphasic clients in clinical practice.

Aims: The current study investigated whether the construct validity of the ANELT could be further improved by substituting the qualitative score by a quantitative one, which takes the number of essential information units into account. The new quantitative measure could have the following advantages: the ability to derive a quantitative score of verbal efficiency, as well as improved sensitivity to detect changes in functional communication over time.

Methods & Procedures: The current study systematically compared a new quantitative measure of verbal effectiveness with the current ANELT Comprehensibility scale, which is based on qualitative judgements. A total of 30 speakers of Dutch participated: 20 non-aphasic speakers and 10 aphasic patients with predominantly expressive disturbances.

Outcomes & Results: Although our findings need to be replicated in a larger group of aphasic speakers, the main results suggest that the new quantitative measure of verbal effectiveness is more sensitive to detect change in verbal effectiveness over time. What is more, it can be used to derive a measure of verbal efficiency.

Conclusions: The fact that both verbal effectiveness and verbal efficiency can be reliably as well as validly measured in the ANELT is of relevance to clinicians. It allows them to obtain a more complete picture of aphasic speakers' functional communication skills.

Keywords:

• Functional communication
• Quantitative measure
• Verbal effectiveness
• Verbal efficiency
• ANELT

Acknowledgments

The study described in this article was supported by the rehabilitation centre of the Sint Maartenskliniek in Nijmegen and conducted in collaboration with the Donders Centre for Cognition as well as the Department of Linguistics of the Radboud University Nijmegen. We would like to thank Marjolein Bruijstens, Lea Maessen, and Berber Spliethoff for their help in collecting the data. We would also like to thank the two anonymous reviewers for their valuable and constructive comments on an earlier version of this paper.

Notes

¹The definition of Content Units implies that words that were produced together were considered to form a unit; however, some inconsistency remains in the definition of CUs. This for example holds for adjectives. Regarding the Cookie Theft Picture of the BDAE, Yorkston and Beukelman (1980) sometimes analysed adjectives as an individual CU (e.g., little) and sometimes as part of another CU (e.g., on the high shelf).

²As the PDT had yielded homogeneous verbal responses of the 10 healthy control speakers in the study by Ruiter (2008), the criterion for relevance was set at 75% for the PDT, which is in line with Christiansen (1995) as well as Huber (1990). As discussed above, the ANELT had yielded much more heterogeneous responses from healthy control speakers (Blomert, 1990). That is the reason why the criterion for relevance was set at 30% for the ANELT-CU scoring procedure.

³Because of a ceiling effect, the ICC is not given for the ANELT-traditional administered to the healthy control speakers.