The use of the Krippendorff’s coefficient in determining intra-rater reliability in human visual quality control of furniture manufacturing processes

Abstract

The use of the Krippendorff’s Coefficient in determining intra-rater reliability in human visual quality control of furniture manufacturing processes. The article presents the results of research on the effectiveness of human visual quality control of furniture manufacturing processes. The aim of this experiment was to check the inter-rater reliability of three elements: the judge, the instruction of which the quality of individual objects made of laminated MDF was determined and the quality assessment by a human. The Krippendorff’s Coefficient was used as a measure of visual control effectiveness. The results of the experiment showed that the use of human visual quality control of furniture manufacturing processes can be a good solution. The values of all three coefficients K1, K2 and K3 gave alpha> 0.8, which is considered a guarantee of high compliance. Therefore, the tested judge turned out to be reliable and competent, the instructions were clear and sufficient, and the figures obtained were reliable. It turned out that the Krippendorff’s Coefficient values differ depending on the number of categories (for two categories K2 = 0.904, K3 = 0.902; for three categories K1 = 0.849). The way the categories were created did not affect the stability of the assessment. The alpha coefficient can undoubtedly be considered a good, convenient measure of monitoring the reliability of the measurement system, because by giving a specific numerical rating, it allows one to control the effectiveness of implemented improvement actions.