{"id":440,"date":"2020-03-19T12:38:40","date_gmt":"2020-03-19T11:38:40","guid":{"rendered":"http:\/\/estatistika.ku.sk\/?page_id=440"},"modified":"2022-03-03T09:10:58","modified_gmt":"2022-03-03T08:10:58","slug":"korelacna-analyza","status":"publish","type":"page","link":"https:\/\/estatistika.ku.sk\/index.php\/induktivna-statistika\/korelacna-analyza\/","title":{"rendered":"Korela\u010dn\u00e1 anal\u00fdza"},"content":{"rendered":"<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Korela\u010dn\u00e1 anal\u00fdza sa zameriava sa na <strong>identifik\u00e1ciu s\u00favislost\u00ed\/korel\u00e1ci\u00ed\/vz\u0165ahov <\/strong>medzi dvomi alebo viacer\u00fdmi premenn\u00fdmi. Zis\u0165uje, \u010di zmeny\u00a0 v jednej premennej s\u00fa sprev\u00e1dzan\u00e9 zmenami v druhej premennej.<\/span><\/p>\n<blockquote>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Napr. m\u00f4\u017eeme zis\u0165ova\u0165, \u010di existuje vz\u0165ah medzi odme\u0148ovan\u00edm zamestnancov a ich v\u00fdkonom (tzn. zmena v odme\u0148ovan\u00ed sa prejav\u00ed v zmene pracovn\u00e9ho v\u00fdkonu); medzi \u00farov\u0148ou IQ a vedomos\u0165ami z matematiky; medzi spokojnos\u0165ou v pr\u00e1ci a syndr\u00f3mom vyhorenia; medzi osobnostnou charakteristikou svedomitos\u0165ou a akademick\u00fdm \u00faspechom; medzi po\u010dtom hod\u00edn u\u010denia sa na sk\u00fa\u0161ku a v\u00fdslednou zn\u00e1mkou a pod.<\/span><\/p>\n<\/blockquote>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Korela\u010dn\u00e1 anal\u00fdza sl\u00fa\u017ei na identifik\u00e1ciu existencie vz\u0165ahu medzi premenn\u00fdmi, pri\u010dom o sile tohto vz\u0165ahu n\u00e1s informuje <strong>korela\u010dn\u00fd koeficient (r). <\/strong>Tento koeficient sa m\u00f4\u017ee pohybova\u0165 v rozp\u00e4t\u00ed medzi -1 a\u017e 1, interpret\u00e1cia je nasledovn\u00e1:<\/span><\/p>\n<ul style=\"text-align: justify;\">\n<li style=\"list-style-type: none;\">\n<ul>\n<li><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">v\u00fdsledok bl\u00edzky &#8222;1&#8220; znamen\u00e1 siln\u00fd <strong>pozit\u00edvny<\/strong> vz\u0165ah (napr. \u010d\u00edm vy\u0161\u0161\u00ed plat, t\u00fdm drah\u0161ie auto),<\/span><\/li>\n<li><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">v\u00fdsledok bl\u00edzky &#8222;\u2013 1&#8220; znamen\u00e1 siln\u00fd <strong>negat\u00edvny<\/strong> vz\u0165ah (napr. \u010d\u00edm vy\u0161\u0161\u00ed plat, t\u00fdm menej vo\u013en\u00e9ho \u010dasu),<\/span><\/li>\n<li><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">v\u00fdsledok bl\u00edzky &#8222;0&#8220; znamen\u00e1 neexistenciu vz\u0165ahu (napr. v\u00fd\u0161ka platu a v\u00fd\u0161ka \u010dloveka).<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Korela\u010dn\u00fd koeficient sa pod\u013ea Cohena interpretuje nasledovne:<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"color: #ff0000; font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><strong>r &lt; 0,1 trivi\u00e1lna korel\u00e1cia,<\/strong><\/span><br \/>\n<span style=\"color: #ff0000; font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><strong>r = 0,1 &#8211; 0,3 slab\u00e1 korel\u00e1cia,<\/strong><\/span><br \/>\n<span style=\"color: #ff0000; font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><strong>r = 0,3 &#8211; 0,5 stredne siln\u00e1 korel\u00e1cia,<\/strong><\/span><br \/>\n<span style=\"color: #ff0000; font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><strong>r &gt; 0,5 siln\u00e1 korel\u00e1cia.<\/strong><\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Prvotn\u00fa anal\u00fdzu d\u00e1t zachyt\u00e1va bodov\u00fd graf (<em>Scatter Plot<\/em>), z ktor\u00e9ho m\u00f4\u017eeme us\u00fadi\u0165, \u010di pri sk\u00faman\u00ed premenn\u00fdch ide o line\u00e1rny vz\u0165ah (vtedy je korela\u010dn\u00e1 anal\u00fdza adekv\u00e1tna), alebo o neline\u00e1rny vz\u0165ah, kedy korela\u010dn\u00e1 anal\u00fdza nie je vhodn\u00e1 &#8211; vi\u010f graf, na ktorom je zobrazen\u00fd line\u00e1rny vz\u0165ah &#8211; \u010d\u00edm dlh\u0161ia prax, t\u00fdm vy\u0161\u0161\u00ed pr\u00edjem.<img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone size-full wp-image-441\" src=\"http:\/\/estatistika.ku.sk\/wp-content\/uploads\/2020\/03\/graf-bodovy.jpg\" alt=\"\" width=\"333\" height=\"260\" srcset=\"https:\/\/estatistika.ku.sk\/wp-content\/uploads\/2020\/03\/graf-bodovy.jpg 333w, https:\/\/estatistika.ku.sk\/wp-content\/uploads\/2020\/03\/graf-bodovy-300x234.jpg 300w\" sizes=\"(max-width: 333px) 100vw, 333px\" \/><\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Pri korela\u010dn\u00fdch anal\u00fdzach zis\u0165ujeme <strong>koeficient korel\u00e1cie (r), <\/strong>ako i\u00a0<strong>hodnotu signifikancie (p).<\/strong><\/span><\/p>\n<blockquote>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Vz\u0165ah zisten\u00fd korela\u010dn\u00fdm koeficientom m\u00f4\u017ee odzrkad\u013eova\u0165 ist\u00fa existuj\u00facu z\u00e1vislos\u0165, av\u0161ak m\u00f4\u017ee by\u0165 aj <strong><em>n\u00e1hodn\u00fd<\/em><\/strong> (t. j. korela\u010dn\u00fd koeficient neodzrkad\u013euje skuto\u010dn\u00fd vz\u0165ah, ale premenn\u00e9 stoja v s\u00fabore vo vz\u0165ahu len n\u00e1hodou). Ak by sme sa pozerali len na hodnotu \u201er\u201c, je mo\u017en\u00e9, \u017ee by sme ozna\u010dili n\u00e1hodn\u00fd vz\u0165ah za existuj\u00faci. Preto je potrebn\u00e9 najsk\u00f4r si v\u0161\u00edma\u0165 hodnotu <strong>signifikancie<\/strong> <strong>(p),<\/strong> ktor\u00e1 ozna\u010duje ve\u013ekos\u0165 tejto chyby a potom ve\u013ekos\u0165 korela\u010dn\u00e9ho koeficientu (r).<\/span><\/p>\n<\/blockquote>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Tradi\u010dne je hodnota signifikancie ustanoven\u00e1 na hladine 0,05, tzn., \u017ee mo\u017enos\u0165 chyby je 5 %. <strong>Hodnoty rovn\u00e9, alebo men\u0161ie ako 0,05 umo\u017e\u0148uj\u00fa pova\u017eova\u0165 vz\u0165ah za existuj\u00faci (resp. systematick\u00fd, nen\u00e1hodn\u00fd) <\/strong>(Gr\u00f6pel, 2008).<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Pri v\u00fdbere relevantn\u00e9ho \u0161tatistick\u00e9ho testu pri korel\u00e1ci\u00e1ch sa prvotne orientujeme v z\u00e1vislosti od typu premennej, pri\u010dom plat\u00ed, \u017ee rozhoduj\u00faca je t\u00e1 premenn\u00e1, ktor\u00e1 je v hierarchii merania na ni\u017e\u0161om stupni (ak napr. meriame vz\u0165ah medzi ordin\u00e1lnou a kardin\u00e1lnou premennou, vyberieme korela\u010dn\u00fd koeficient pre ordin\u00e1lne premenn\u00e9):<\/span><\/p>\n<ul style=\"text-align: justify;\">\n<li><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">vz\u0165ahy medzi <a href=\"http:\/\/estatistika.ku.sk\/index.php\/induktivna-statistika\/komparacna-analyza\/komparacia-suborov-podla-nominalnej-premennej\/\">nomin\u00e1lnymi<\/a> premenn\u00fdmi,<\/span><\/li>\n<li><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">vz\u0165ahy medzi <a href=\"http:\/\/estatistika.ku.sk\/index.php\/induktivna-statistika\/komparacna-analyza\/komparacia-suborov-podla-ordinalnej-premennej\/priklad-kruskal-wallis-test\/\">ordin\u00e1lnymi <\/a>premenn\u00fdmi,<\/span><\/li>\n<li><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">vz\u0165ahy medzi <a href=\"http:\/\/estatistika.ku.sk\/index.php\/induktivna-statistika\/komparacna-analyza\/komparacia-suborov-podla-kardinalnej-premennej-2\/\">kardin\u00e1lnymi <\/a>premenn\u00fdmi.<\/span><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Korela\u010dn\u00e1 anal\u00fdza sa zameriava sa na identifik\u00e1ciu s\u00favislost\u00ed\/korel\u00e1ci\u00ed\/vz\u0165ahov medzi dvomi alebo viacer\u00fdmi premenn\u00fdmi. Zis\u0165uje, \u010di zmeny\u00a0 v jednej premennej s\u00fa sprev\u00e1dzan\u00e9 zmenami v druhej premennej. Napr. m\u00f4\u017eeme zis\u0165ova\u0165, \u010di existuje vz\u0165ah medzi odme\u0148ovan\u00edm zamestnancov a ich v\u00fdkonom (tzn. zmena v odme\u0148ovan\u00ed sa prejav\u00ed v zmene pracovn\u00e9ho v\u00fdkonu); medzi \u00farov\u0148ou IQ a vedomos\u0165ami z matematiky; medzi [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":17,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"templates\/template-full-width.php","meta":{"footnotes":""},"class_list":["post-440","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages\/440","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/comments?post=440"}],"version-history":[{"count":14,"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages\/440\/revisions"}],"predecessor-version":[{"id":2259,"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages\/440\/revisions\/2259"}],"up":[{"embeddable":true,"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages\/17"}],"wp:attachment":[{"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/media?parent=440"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}