{"id":4644,"date":"2026-08-12T15:47:52","date_gmt":"2026-08-12T13:47:52","guid":{"rendered":"https:\/\/ellistat.com\/?post_type=guide-dutilisateur&#038;p=4644"},"modified":"2026-08-12T15:47:52","modified_gmt":"2026-08-12T13:47:52","slug":"appendix-definitions-4","status":"publish","type":"guide-dutilisateur","link":"https:\/\/ellistat.com\/en\/guide-dutilisateur\/annexe-definitions-2\/","title":{"rendered":"Appendix: Definitions"},"content":{"rendered":"<ul class=\"wp-block-list\">\n<li><strong>Short-term dispersion<\/strong>\u00a0: variability within samples, excluding deviations. What the process is capable of at that moment.<\/li>\n\n\n\n<li>\u00a0<strong>Overall dispersion<\/strong>\u00a0: all observed variability, including drift.<\/li>\n\n\n\n<li><strong>Cp, Cpk<\/strong>\u00a0: short-term capabilities \u2014 potential.\u00a0<strong>Cpk<\/strong>\u00a0takes alignment into account.<\/li>\n\n\n\n<li><strong>Pp, Ppk<\/strong>\u00a0: Performance calculated based on overall variance \u2014 actual results.<\/li>\n\n\n\n<li><strong>Compliance with the Law<\/strong>\u00a0: the quality of the fit between the data and the chosen model. This determines the validity of all subsequent conclusions.<\/li>\n\n\n\n<li><strong>Henry's Right<\/strong>\u00a0: A graph in which a population following the fitted law aligns with a straight line.<\/li>\n\n\n\n<li><strong>EWMA<\/strong>\u00a0: exponentially weighted moving average, sensitive to small, sustained deviations.<\/li>\n\n\n\n<li><strong>Overdispersion<\/strong>\u00a0: variability greater than that predicted by the binomial or Poisson distribution, typical of large batches. This explains the Laney charts.<\/li>\n\n\n\n<li><strong>Phase I<\/strong>\u00a0: reference period used to establish control limits.<\/li>\n<\/ul>","protected":false},"featured_media":0,"menu_order":110,"template":"","meta":{"_acf_changed":true},"menu-guide-dutilisateur":[22],"class_list":["post-4644","guide-dutilisateur","type-guide-dutilisateur","status-publish","hentry","menu-guide-dutilisateur-4-statistiques-descriptives"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Annexe : d\u00e9finitions - Ellistat<\/title>\n<meta name=\"description\" content=\"Dispersion court terme, ad\u00e9quation de loi, EWMA, Phase I, sur-dispersion : toutes les d\u00e9finitions essentielles pour comprendre le contr\u00f4le statistique de proc\u00e9d\u00e9.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/ellistat.com\/en\/users-guide\/appendix-definitions-4\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Annexe : d\u00e9finitions - 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