{"id":635,"date":"2020-03-31T13:41:31","date_gmt":"2020-03-31T11:41:31","guid":{"rendered":"http:\/\/estatistika.ku.sk\/?page_id=635"},"modified":"2022-01-09T02:25:36","modified_gmt":"2022-01-09T01:25:36","slug":"nahodny-vyber","status":"publish","type":"page","link":"https:\/\/estatistika.ku.sk\/index.php\/vyber-vyskumnej-vzorky\/nahodny-vyber\/","title":{"rendered":"N\u00e1hodn\u00fd v\u00fdber"},"content":{"rendered":"<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><strong>N\u00e1hodn\u00fd\/ pravdepodobnostn\u00fd v\u00fdber<\/strong> je korektnou vedeckou met\u00f3dou v\u00fdberu, ktorej <span style=\"text-align: justify;\">z\u00e1kladnou charakteristikou je, \u017ee s ve\u013ekou pravdepodobnos\u0165ou odr\u00e1\u017ea vlastnosti celej popul\u00e1cie. Takto z\u00edskan\u00e9 d\u00e1ta s\u00fa reprezentat\u00edvne a v\u00fdsledky je mo\u017en\u00e9 zov\u0161eobecni\u0165. Nie je z\u00e1visl\u00fd na subjekt\u00edvnom odhade v\u00fdskumn\u00edka ako je to napr. v pr\u00edpade kv\u00f3tneho v\u00fdberu.<\/span><\/span><\/p>\n<blockquote>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><em>Napr. v\u00fdskumn\u00edk zis\u0165uje \u00farove\u0148 \u0161tatistickej gramotnosti u \u0161tudentov Pedagogickej fakulty Katol\u00edckej univerzity. Zist\u00ed, \u017ee popul\u00e1ciu (z\u00e1kladn\u00fd s\u00fabor) tvor\u00ed 1 500 \u0161tudentov. Prostredn\u00edctvom kalkula\u010dky ve\u013ekosti v\u00fdberovej vzorky: <a href=\"https:\/\/www.surveysystem.com\/sscalc.htm\" target=\"_blank\" rel=\"noopener noreferrer\">sample size calculator<\/a>, zist\u00ed, \u017ee do v\u00fdberov\u00e9ho s\u00faboru potrebuje 306 \u0161tudentov. Cel\u00e9mu z\u00e1kladn\u00e9mu s\u00faboru, teda 1500 \u0161tudentom prirad\u00ed \u010d\u00edsla od 1 do 1500 a n\u00e1hodne (prostredn\u00edctvom napr. <a href=\"https:\/\/www.itnetwork.cz\/javascript-online-generator-nahodnych-random-cisel-se-zvolitelnym-rozsahem\" target=\"_blank\" rel=\"noopener noreferrer\">gener\u00e1tora n\u00e1hodn\u00fdch \u010d\u00edsel<\/a>) vyberie v\u00fdberov\u00fd s\u00fabor &#8211; teda 306 \u0161tudentov (respondentov). E\u0161te vhodnej\u0161\u00edm sp\u00f4sobom v\u00fdberu v\u00fdskumn\u00e9ho s\u00faboru s\u00fa \u0161pecializovan\u00e9 postupy v programe SPSS.\u00a0 Mus\u00ed by\u0165 zachovan\u00e1 podmienka toho, \u017ee ka\u017ed\u00fd \u0161tudent m\u00e1 rovnak\u00fa \u0161ancu dosta\u0165 sa do v\u00fdberov\u00e9ho s\u00faboru.<\/em><\/span><\/p>\n<\/blockquote>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\"><strong>Jednoduch\u00fd n\u00e1hodn\u00fd v\u00fdber<\/strong> &#8211; ka\u017ed\u00fd subjekt m\u00e1 rovnak\u00fa \u0161ancu (pravdepodobnos\u0165) dosta\u0165 sa do v\u00fdberov\u00e9ho s\u00faboru.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">V\u00fdber jednotiek do v\u00fdberov\u00e9ho s\u00faboru sa realizuje napr. losovan\u00edm, pomocou tabuliek n\u00e1hodn\u00fdch \u010d\u00edsel \u010di pomocou online gener\u00e1tora n\u00e1hodn\u00fdch \u010d\u00edsel.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">S<strong>tratifikovan\u00fd n\u00e1hodn\u00fd v\u00fdber <\/strong>&#8211; podstata spo\u010d\u00edva v tom, \u017ee z\u00e1kladn\u00fd s\u00fabor je rozdelen\u00fd do homog\u00e9nnych podskup\u00edn (podmno\u017e\u00edn), na z\u00e1klade ur\u010dit\u00fdch podstatn\u00fdch znakov (napr. kraj, pohlavie, vek, n\u00e1rodnos\u0165, bydlisko, vzdelanie a pod.). Z ka\u017edej podmno\u017einy sa potom respondenti vyberaj\u00fa samostatne, n\u00e1hodn\u00fdm sp\u00f4sobom. <em>Napr. potrebujeme vybra\u0165 v\u00fdskumn\u00fd s\u00fabor rozlo\u017een\u00fd propor\u010dne pod\u013ea kraja.\u00a0<\/em><\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">V\u00fdberov\u00fd s\u00fabor by mal by\u0165 vytvoren\u00fd tak, aby v men\u0161om rozsahu kop\u00edroval zlo\u017eenie z\u00e1kladn\u00e9ho s\u00faboru. <em>Ak by sme napr. chceli sk\u00fama\u0165 \u00farove\u0148 \u0161tatistickej gramotnosti \u0161tudentov Pedagogickej fakulty v\u00a0Ru\u017eomberku (na pedagogickej fakulte \u0161tuduj\u00fa \u0161tudenti r\u00f4zne u\u010dite\u013esk\u00e9 kombin\u00e1cie, ale aj soci\u00e1lnu pr\u00e1cu&#8230;.) a\u00a0v\u00fdberov\u00fd s\u00fabor by sme vytvorili len zo \u0161tudentov u\u010dite\u013estva matematiky a informatiky, nemohli by sme tento v\u00fdsledok zov\u0161eobecni\u0165 pre cel\u00fa fakultu.<\/em><\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">Probl\u00e9my, ktor\u00e9 b\u00fdvaj\u00fa s t\u00fdmto typom v\u00fdberu spojen\u00e9 s\u00fa, \u017ee nie v\u017edy m\u00e1me k dispoz\u00edcii zoznam v\u0161etk\u00fdch jednotiek z\u00e1kladn\u00e9ho s\u00faboru a v pr\u00edpade, ak ho aj m\u00e1me, nie v\u0161etci vybran\u00ed s\u00fa ochotn\u00ed z\u00fa\u010dastni\u0165 sa v\u00fdberu.<\/span><\/p>\n<p style=\"text-align: justify;\"><span style=\"font-family: helvetica, arial, sans-serif; font-size: 14pt;\">K n\u00e1hodn\u00fdm v\u00fdberom patr\u00ed i tzv. <strong>Met\u00f3da n\u00e1hodnej prech\u00e1dzky<\/strong>, ktor\u00e1 sa pou\u017e\u00edva v pr\u00edpade, ke\u010f cie\u013eovou skupinou s\u00fa dom\u00e1cnosti, av\u0161ak neexistuje \u017eiadna relevantn\u00e1 opora v\u00fdberu (zoznam dom\u00e1cnost\u00ed).\u00a0 Opytovate\u013e\/anket\u00e1r dostane inform\u00e1ciu, kde by mal za\u010da\u0165 (napr. ulicu, \u010d\u00edslo domu n\u00e1hodne vylosovan\u00e9), a potom m\u00e1 postup, ako pokra\u010dova\u0165 \u010falej (napr. si vylosuje \u010fal\u0161iu ulicu).<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>N\u00e1hodn\u00fd\/ pravdepodobnostn\u00fd v\u00fdber je korektnou vedeckou met\u00f3dou v\u00fdberu, ktorej z\u00e1kladnou charakteristikou je, \u017ee s ve\u013ekou pravdepodobnos\u0165ou odr\u00e1\u017ea vlastnosti celej popul\u00e1cie. Takto z\u00edskan\u00e9 d\u00e1ta s\u00fa reprezentat\u00edvne a v\u00fdsledky je mo\u017en\u00e9 zov\u0161eobecni\u0165. Nie je z\u00e1visl\u00fd na subjekt\u00edvnom odhade v\u00fdskumn\u00edka ako je to napr. v pr\u00edpade kv\u00f3tneho v\u00fdberu. Napr. v\u00fdskumn\u00edk zis\u0165uje \u00farove\u0148 \u0161tatistickej gramotnosti u \u0161tudentov Pedagogickej fakulty [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"parent":630,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"templates\/template-full-width.php","meta":{"footnotes":""},"class_list":["post-635","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages\/635","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=635"}],"version-history":[{"count":25,"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages\/635\/revisions"}],"predecessor-version":[{"id":1737,"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages\/635\/revisions\/1737"}],"up":[{"embeddable":true,"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/pages\/630"}],"wp:attachment":[{"href":"https:\/\/estatistika.ku.sk\/index.php\/wp-json\/wp\/v2\/media?parent=635"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}