{"id":887,"date":"2024-07-12T11:14:08","date_gmt":"2024-07-12T11:14:08","guid":{"rendered":"http:\/\/www.ohsumin.com\/?p=887"},"modified":"2025-06-11T01:23:00","modified_gmt":"2025-06-11T01:23:00","slug":"%ed%81%ac%eb%a1%a0%eb%b0%94%ed%95%98-%ec%95%8c%ed%8c%8ccronbachs-alpha","status":"publish","type":"post","link":"http:\/\/www.inmining.co.kr\/?p=887","title":{"rendered":"\ud06c\ub860\ubc14\ud558 \uc54c\ud30c(Cronbach’s Alpha)"},"content":{"rendered":"\n\n\n

\\(\\)<\/p>\n\n\n\n

\ud06c\ub860\ubc14\ud750 \uc54c\ud30c(Cronbach’s Alpha)\ub294 \uce21\uc815 \ub3c4\uad6c(\uc608: \uc124\ubb38\uc9c0, \ud14c\uc2a4\ud2b8)\uc758 \ub0b4\uc801 \uc77c\uad00\uc131\uc744 \ud3c9\uac00\ud558\ub294 \ub370 \uc0ac\uc6a9\ub418\ub294 \ud1b5\uacc4\uc801 \uc9c0\ud45c\uc785\ub2c8\ub2e4. \ub0b4\uc801 \uc77c\uad00\uc131\uc740 \uce21\uc815 \ub3c4\uad6c\uc758 \uc5ec\ub7ec \ubb38\ud56d\ub4e4\uc774 \ub3d9\uc77c\ud55c \uac1c\ub150\uc744 \uc77c\uad00\ub418\uac8c \uce21\uc815\ud558\ub294\uc9c0\ub97c \ub098\ud0c0\ub0c5\ub2c8\ub2e4. \ud06c\ub860\ubc14\ud750 \uc54c\ud30c\ub294 0\uc5d0\uc11c 1 \uc0ac\uc774\uc758 \uac12\uc744 \uac00\uc9c0\uba70, \uac12\uc774 \ud074\uc218\ub85d \ubb38\ud56d\ub4e4 \uac04\uc758 \uc77c\uad00\uc131\uc774 \ub192\uc74c\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n

<\/span>\ud06c\ub860\ubc14\ud750 \uc54c\ud30c\uc758 \uacc4\uc0b0<\/span><\/h3>\n\n\n\n

\ud06c\ub860\ubc14\ud750 \uc54c\ud30c\ub294 \ub2e4\uc74c\uacfc \uac19\uc740 \uacf5\uc2dd\uc73c\ub85c \uacc4\uc0b0\ub429\ub2c8\ub2e4:<\/p>\n\n\n\n

\\[ \\alpha = \\frac{N}{N-1} \\left( 1 – \\frac{\\sum_{i=1}^{N} \\sigma^2_{Y_i}}{\\sigma^2_X} \\right) \\]<\/p>\n\n\n\n

\uc5ec\uae30\uc11c:<\/p>\n\n\n\n

    \n
  • \\( \\alpha \\)\ub294 \ud06c\ub860\ubc14\ud750 \uc54c\ud30c \uac12<\/li>\n\n\n\n
  • \\( N \\)\ub294 \ubb38\ud56d\uc758 \uc218<\/li>\n\n\n\n
  • \\( \\sigma^2_{Y_i} \\)\ub294 \uac01 \ubb38\ud56d\uc758 \ubd84\uc0b0<\/li>\n\n\n\n
  • \\( \\sigma^2_X \\)\ub294 \ucd1d \ubb38\ud56d \uc810\uc218\uc758 \ubd84\uc0b0<\/li>\n<\/ul>\n\n\n\n

    \uac04\ub2e8\ud788 \ub9d0\ud574\uc11c, \ud06c\ub860\ubc14\ud750 \uc54c\ud30c\ub294 \uac01 \ubb38\ud56d\uc758 \ubd84\uc0b0\uacfc \ucd1d \uc810\uc218\uc758 \ubd84\uc0b0\uc744 \ube44\uad50\ud558\uc5ec \uacc4\uc0b0\ub429\ub2c8\ub2e4.<\/p>\n\n\n\n

    <\/span>\uacc4\uc0b0 \ub2e8\uacc4<\/span><\/h3>\n\n\n\n
      \n
    1. \uac01 \ubb38\ud56d\uc758 \ubd84\uc0b0 \uacc4\uc0b0<\/strong>: \uc124\ubb38\uc9c0\ub098 \ud14c\uc2a4\ud2b8\uc758 \uac01 \ubb38\ud56d\uc5d0 \ub300\ud55c \uc751\ub2f5\uc758 \ubd84\uc0b0\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n
    2. \ucd1d \uc810\uc218\uc758 \ubd84\uc0b0 \uacc4\uc0b0<\/strong>: \ubaa8\ub4e0 \ubb38\ud56d\uc758 \uc810\uc218\ub97c \ud569\uc0b0\ud55c \ucd1d \uc810\uc218\uc758 \ubd84\uc0b0\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n
    3. \ud06c\ub860\ubc14\ud750 \uc54c\ud30c \uacc4\uc0b0<\/strong>: \uc704 \uacf5\uc2dd\uc744 \uc0ac\uc6a9\ud558\uc5ec \ud06c\ub860\ubc14\ud750 \uc54c\ud30c \uac12\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n<\/ol>\n\n\n\n

      <\/span>\ud06c\ub860\ubc14\ud750 \uc54c\ud30c\uc758 \ud574\uc11d<\/span><\/h3>\n\n\n\n
        \n
      • 0.9 \uc774\uc0c1<\/strong>: \ub9e4\uc6b0 \ub192\uc740 \uc2e0\ub8b0\ub3c4 (Excellent)<\/li>\n\n\n\n
      • 0.8 \uc774\uc0c1<\/strong>: \ub192\uc740 \uc2e0\ub8b0\ub3c4 (Good)<\/li>\n\n\n\n
      • 0.7 \uc774\uc0c1<\/strong>: \uc218\uc6a9 \uac00\ub2a5\ud55c \uc2e0\ub8b0\ub3c4 (Acceptable)<\/li>\n\n\n\n
      • 0.6 \uc774\uc0c1<\/strong>: \uc758\uc2ec\uc2a4\ub7ec\uc6b4 \uc2e0\ub8b0\ub3c4 (Questionable)<\/li>\n\n\n\n
      • 0.5 \uc774\uc0c1<\/strong>: \ub0ae\uc740 \uc2e0\ub8b0\ub3c4 (Poor)<\/li>\n\n\n\n
      • 0.5 \ubbf8\ub9cc<\/strong>: \ub9e4\uc6b0 \ub0ae\uc740 \uc2e0\ub8b0\ub3c4 (Unacceptable)<\/li>\n<\/ul>\n\n\n\n

        \uc774 \ud574\uc11d\uc740 \uc77c\ubc18\uc801\uc778 \uae30\uc900\uc774\uba70, \uc0c1\ud669\uc5d0 \ub530\ub77c \ub2e4\ub97c \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc608\ub97c \ub4e4\uc5b4, \uc2ec\ub9ac\ud559 \uc5f0\uad6c\uc5d0\uc11c\ub294 0.7 \uc774\uc0c1\uc744 \uc218\uc6a9 \uac00\ub2a5\ud55c \uc2e0\ub8b0\ub3c4\ub85c \ubcf4\ub294 \uacbd\uc6b0\uac00 \ub9ce\uc2b5\ub2c8\ub2e4.<\/p>\n\n\n\n

        <\/span>\uc608\uc81c<\/span><\/h3>\n\n\n\n

        \ub2e4\uc74c\uc740 \uc124\ubb38\uc9c0\uc758 \ud06c\ub860\ubc14\ud750 \uc54c\ud30c\ub97c \uacc4\uc0b0\ud558\ub294 \uc608\uc785\ub2c8\ub2e4. 5\uac1c\uc758 \ubb38\ud56d\uc73c\ub85c \uad6c\uc131\ub41c \uc124\ubb38\uc9c0\uac00 \uc788\ub2e4\uace0 \uac00\uc815\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n

          \n
        1. \uac01 \ubb38\ud56d\uc758 \ubd84\uc0b0\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n
        2. \ucd1d \uc810\uc218\uc758 \ubd84\uc0b0\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n
        3. \ud06c\ub860\ubc14\ud750 \uc54c\ud30c \uacf5\uc2dd\uc744 \uc0ac\uc6a9\ud558\uc5ec \uac12\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n<\/ol>\n\n\n\n

          Python \uc608\uc81c \ucf54\ub4dc<\/h4>\n\n\n\n
          import numpy as np\n\n# \uc608\uc81c \ub370\uc774\ud130: \uac01 \ubb38\ud56d\uc5d0 \ub300\ud55c \uc751\ub2f5\ndata = np.array([\n    [4, 3, 5, 4, 5],\n    [3, 3, 4, 4, 4],\n    [4, 4, 4, 3, 4],\n    [5, 4, 5, 5, 5],\n    [3, 3, 3, 3, 3]\n])\n\n# \uac01 \ubb38\ud56d\uc758 \ubd84\uc0b0\nitem_variances = np.var(data, axis=0, ddof=1)\n\n# \ucd1d \uc810\uc218\uc758 \ubd84\uc0b0\ntotal_score_variance = np.var(np.sum(data, axis=1), ddof=1)\n\n# \ubb38\ud56d \uc218\nnum_items = data.shape[1]\n\n# \ud06c\ub860\ubc14\ud750 \uc54c\ud30c \uacc4\uc0b0\ncronbach_alpha = (num_items \/ (num_items - 1)) * (1 - np.sum(item_variances) \/ total_score_variance)\n\nprint(f'\ud06c\ub860\ubc14\ud750 \uc54c\ud30c: {cronbach_alpha:.2f}')<\/code><\/pre>\n\n\n\n
          <\/span>\uc608\uc81c2<\/span><\/h3>\n\n\n\n
          \ub2e4\uc74c\uc740 \uac04\ub2e8\ud55c \uc608\uc81c\ub85c, 3\uac1c\uc758 \ubb38\ud56d\uc73c\ub85c \uad6c\uc131\ub41c \uc124\ubb38\uc9c0\uc758 \ud06c\ub860\ubc14\ud750 \uc54c\ud30c\ub97c \uacc4\uc0b0\ud558\ub294 \ubc29\ubc95\uc785\ub2c8\ub2e4.<\/p>\n\n\n\n
          \uc608\uc81c \ub370\uc774\ud130<\/h4>\n\n\n\n
          \uc751\ub2f5\uc790<\/th>\ubb38\ud56d 1<\/th>\ubb38\ud56d 2<\/th>\ubb38\ud56d 3<\/th><\/tr><\/thead>
          1<\/td>4<\/td>3<\/td>5<\/td><\/tr>
          2<\/td>3<\/td>4<\/td>4<\/td><\/tr>
          3<\/td>4<\/td>4<\/td>3<\/td><\/tr>
          4<\/td>5<\/td>5<\/td>5<\/td><\/tr>
          5<\/td>3<\/td>3<\/td>3<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
          Python \ucf54\ub4dc\ub85c \uacc4\uc0b0<\/h4>\n\n\n\n
          \ub2e4\uc74c\uc740 Python\uc744 \uc0ac\uc6a9\ud558\uc5ec \ud06c\ub860\ubc14\ud750 \uc54c\ud30c\ub97c \uacc4\uc0b0\ud558\ub294 \ucf54\ub4dc\uc785\ub2c8\ub2e4.<\/p>\n\n\n\n
          import numpy as np\n\n# \uc608\uc81c \ub370\uc774\ud130\ndata = np.array([\n    [4, 3, 5],\n    [3, 4, 4],\n    [4, 4, 3],\n    [5, 5, 5],\n    [3, 3, 3]\n])\n\n# \uac01 \ubb38\ud56d\uc758 \ubd84\uc0b0\nitem_variances = np.var(data, axis=0, ddof=1)\n\n# \ucd1d \uc810\uc218\uc758 \ubd84\uc0b0\ntotal_score_variance = np.var(np.sum(data, axis=1), ddof=1)\n\n# \ubb38\ud56d \uc218\nnum_items = data.shape[1]\n\n# \ud06c\ub860\ubc14\ud750 \uc54c\ud30c \uacc4\uc0b0\ncronbach_alpha = (num_items \/ (num_items - 1)) * (1 - np.sum(item_variances) \/ total_score_variance)\n\nprint(f'\ud06c\ub860\ubc14\ud750 \uc54c\ud30c: {cronbach_alpha:.2f}')<\/code><\/pre>\n\n\n\n
          \uc774 \ucf54\ub4dc\uc5d0\uc11c:<\/p>\n\n\n\n
            \n
          • data<\/code>\ub294 \uac01 \uc751\ub2f5\uc790\uc758 \uc124\ubb38\uc9c0 \uc751\ub2f5 \ub370\uc774\ud130\ub97c \ub098\ud0c0\ub0c5\ub2c8\ub2e4.<\/li>\n\n\n\n
          • item_variances<\/code>\ub294 \uac01 \ubb38\ud56d\uc758 \ubd84\uc0b0\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n
          • total_score_variance<\/code>\ub294 \uac01 \uc751\ub2f5\uc790\uc758 \ucd1d \uc810\uc218\uc758 \ubd84\uc0b0\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n\n\n\n
          • cronbach_alpha<\/code>\ub294 \ud06c\ub860\ubc14\ud750 \uc54c\ud30c \uac12\uc744 \uacc4\uc0b0\ud569\ub2c8\ub2e4.<\/li>\n<\/ul>\n\n\n\n
            \uc774 \uc608\uc81c\uc5d0\uc11c\ub294 \ud06c\ub860\ubc14\ud750 \uc54c\ud30c\uac00 0.83\uc73c\ub85c \uacc4\uc0b0\ub418\uc5c8\uc74c\uc744 \uc54c \uc218 \uc788\uc2b5\ub2c8\ub2e4. \uc774\ub294 \ud574\ub2f9 \uc124\ubb38\uc9c0\uc758 \ub0b4\uc801 \uc77c\uad00\uc131\uc774 \ub192\uc740 \ud3b8\uc784\uc744 \uc758\ubbf8\ud569\ub2c8\ub2e4.<\/p>\n\n\n\n
            <\/span>\uacb0\ub860<\/span><\/h3>\n\n\n\n
            \ud06c\ub860\ubc14\ud750 \uc54c\ud30c\ub294 \uce21\uc815 \ub3c4\uad6c\uc758 \ub0b4\uc801 \uc77c\uad00\uc131\uc744 \ud3c9\uac00\ud558\ub294 \ub370 \uc911\uc694\ud55c \uc9c0\ud45c\uc785\ub2c8\ub2e4. \uc774\ub97c \ud1b5\ud574 \uc124\ubb38\uc9c0\ub098 \ud14c\uc2a4\ud2b8\uc758 \ubb38\ud56d\ub4e4\uc774 \ub3d9\uc77c\ud55c \uac1c\ub150\uc744 \uc77c\uad00\ub418\uac8c \uce21\uc815\ud558\ub294\uc9c0 \ud655\uc778\ud560 \uc218 \uc788\uc2b5\ub2c8\ub2e4. \ud06c\ub860\ubc14\ud750 \uc54c\ud30c \uac12\uc774 \ub192\uc744\uc218\ub85d \uc2e0\ub8b0\ub3c4\uac00 \ub192\uc74c\uc744 \ub098\ud0c0\ub0b4\uba70, \uc77c\ubc18\uc801\uc73c\ub85c 0.7 \uc774\uc0c1\uc774\uba74 \uc218\uc6a9 \uac00\ub2a5\ud55c \uc2e0\ub8b0\ub3c4\ub97c \uc758\ubbf8\ud569\ub2c8\ub2e4.<\/p>\n","protected":false},"excerpt":{"rendered":"
            \ud06c\ub860\ubc14\ud750 \uc54c\ud30c(Cronbach’s Alpha)\ub294 \uce21\uc815 \ub3c4\uad6c(\uc608: \uc124\ubb38\uc9c0, \ud14c\uc2a4\ud2b8)\uc758 \ub0b4\uc801 \uc77c\uad00\uc131\uc744 \ud3c9\uac00\ud558\ub294 \ub370 \uc0ac\uc6a9\ub418\ub294 \ud1b5\uacc4\uc801 \uc9c0\ud45c\uc785\ub2c8\ub2e4. \ub0b4\uc801 \uc77c\uad00\uc131\uc740 \uce21\uc815 \ub3c4\uad6c\uc758…<\/p>\n","protected":false},"author":1,"featured_media":892,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-887","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-stat","wpcat-6-id"],"_links":{"self":[{"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/887","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=887"}],"version-history":[{"count":2,"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/887\/revisions"}],"predecessor-version":[{"id":891,"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=\/wp\/v2\/posts\/887\/revisions\/891"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=\/wp\/v2\/media\/892"}],"wp:attachment":[{"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=887"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=887"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.inmining.co.kr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=887"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}