Parallel and identical test–retest reliability of the Tower of London test – Freiburg version

• Published in: Journal of the International Neuropsychological Society Vol. 29; no. 8; pp. 783 - 788
• Main Authors: Schyle, Valentin, Schumacher, Lena V., Rahm, Benjamin, Unterrainer, Josef M.
• Format: Journal Article
• Language: English
• Published: New York, USA Cambridge University Press 01.10.2023
• Subjects: identical test–retest reliability; Tower of London Test – Freiburg version; parallel test–retest reliability; intraclass correlation coefficients
• ISSN: 1355-6177; 1469-7661
• DOI: 10.1017/S1355617722000911

The Tower of London - Freiburg version (TOL-F) was developed in three parallel-test versions (A, B, and C) that only differ in their physical appearance by interchanged ball colors, but not in their cognitive demands. We addressed the question whether the test-retest reliability of an identical problem set differs from the parallel test-retest reliability of a structurally identical problem set with a marginally different physical appearance. Reliabilities were assessed in two samples of young adults over a 1-week interval: In the parallel test-retest sample ( = 93; 49 female), half of the participants accomplished version A at the first session and version B at the second session, while the other half started with version B in the first session and continued with A in the second session. In the identical test-retest sample ( = 86; 48 female), half of the participants performed on version A in both the first and the second session, while the other half went through the same procedure with version B. For overall planning accuracy, intraclass correlation coefficients for absolute agreement were = .501 for the parallel test-retest and = .605 for the identical test-retest sample, with Pearson correlations of = .559 and = .708 respectively. Greatest lower bound estimates of reliability were adequate to high in the two samples (ranging between .765 and .854) confirming previous studies. Although the TOL-F revealed only moderate intraclass correlations for absolute agreement, it showed some of the highest psychometric indices compared to repeated assessments with other TOL tests.