1. The judging in artistic gymnastics crucially determines outcome. Currently, final score is a sum of difficulty score and execution (E) score by the panel of 6 judges. E score is calculated by subtracting deductions for various mistakes from 10 points, including the deductions for flaws in artistry. Evaluation of artistry could be associated with serious insufficiencies of reliability and validity. We have analyzed the reliability and validity of deductions in artistry at one of the top gymnastics competitions. Introduction Methods The evaluated categories of artistry are: inappropriate gesture or mimic, insufficient variation in rhythm, sureness of performance and lack of creative choreography. We have used the data from judge evaluation sheets to examine the deductions for artistry for each individual contestant. We have calculated the correlation coefficients (Kendall's tau-b) for association between the total artistry deduction and final E score. Same method was used to calculate the correlations in separate categories of artistry between all possible judge-pairs. Finally, the special aspect of judging validity was examined by calculating the Kendall's W statistic - this method gives high and statistically significant values of W, when individual judges systematically give relatively high or low deductions (systematic bias). RELIABILITY AND VALIDITY OF JUDGING ARTISTRY ON BALANCE BEAM AT WORLD CHAMPIONSHIP IN TOKIO 2011 M. Bučar 1, I. Čuk 1, J. Pajek 2, M. Kovač 1, B. Leskovšek 1 1 Faculty of sport, University of Ljubljana Slovenia 2 University Medical Centre, Ljubljana Slovenia Results The number of contestants penalized for other components of artistry was highly variable between the judges: no deduction for insufficient variation in rhythm was given to either 10 contestants (judge 5), 46-88 contestants (judges 1,3 and 4), but even up to 138 contestants (judge 2). High variability was found in the magnitude of deductions: for the sureness of performance judge 1 used the 0,3 deduction in 158 contestants and judge 3 in only 9 contestants. The range of mean total deductions for artistry was 0,18-0,39. The average Kendall's tau-b correlation coefficient between the total artistry deduction and final E score for the 5 judges was -0,61 (range -0,49 to -0,71, p for all <0,001). The average correlation between judge pairs in same artistry categories was 0,45 (range 0,01-0,83). When the total artistry deductions were examined for validity, the Kendall's W statistic was high: 0,53 (p<0,001). The highest problems in validity were found in sureness of performance: Kendall's W 0,53 (p<0.001). Conclusions Our results have shown that reliability of judging artistry is low: there was a high variability between the judges in the number of penalized contestants in separate categories of artistry and a very low average correlation between judge- pairs for the same categories of artistry. Of highest concern is our finding of significant systematic bias between judges implicating a lack of validity. It is clear that we have to monitor the judging of artistry in future and if such findings are repetitively found, the justification for including artistry deductions should be reassessed by the regulating body (FIG). maja.bucarpajek@fsp.uni-lj.si