Inter- and intra-rater reliability of swimming teachers with different skill levels, in different conditions, evaluating front crawl arm movement in non-expert swimmers

Abstract

This study aimed (i) to test the inter-rater reliability of swimming teachers, (ii) to test the swimming teacher's discussion effect on inter-rater reliability and (iii) to verify the intra-rater swimming teacher's reliability.Method: Twenty-one learning swimmers (14.1 ± 5.1 years old) performed two 25-m front crawl courses at a comfortable speed without breathing between the sixth and 20-m, and had their displacements captured on film. Three swimming teachers with different academic backgrounds and skills evaluated the swimmer right upper limb using a 20-items checklist. In the 1 st -step, teachers assessed 20-items and in 2 nd -step discussed their particular evaluating criteriaselecting five items considered as the most relevant. The inter-and intra-rater reliability were tested using the Fleiss Kappa Coefficient. Results: In the 1 st -step substantial reliability was found for item three and in movement descriptor for items three and 20. Nearly perfect reliability was found in the movement descriptor for item 13. In 2 nd -step, moderate reliability was found only in the movement descriptor for item 20. Only the most experienced evaluator showed substantial intra-rater reliability for items four and 10 and moderate for item 20. Conclusion: The proposed discussion method did not cause the expected effect on inter-rater reliability. The swimming teacher with a higher degree and swimming skills showed better intra-rater reliability. Some items and movement descriptors proposed at the 20-items checklist can be used in practical settings.