{"id":1240,"date":"2026-03-18T17:28:41","date_gmt":"2026-03-18T14:28:41","guid":{"rendered":"https:\/\/www.istatistik.gen.tr\/?p=1240"},"modified":"2026-03-18T21:08:04","modified_gmt":"2026-03-18T18:08:04","slug":"rye-baslangic","status":"publish","type":"post","link":"https:\/\/www.istatistik.gen.tr\/?p=1240","title":{"rendered":"R’ye Ba\u015flang\u0131\u00e7:"},"content":{"rendered":"\n

R ile \u0130statistik<\/p>\n\n\n\n

Vekt\u00f6r nedir, data frame nedir bunlar\u0131 unutun. \u00d6nce ger\u00e7ek bir analiz yap\u0131n.<\/p>\n\n\n\n

Bu yaz\u0131da neler var?<\/p>\n\n\n\n

    \n
  1. Neden \u00e7o\u011fu R kursu sizi kaybediyor?<\/a><\/li>\n\n\n\n
  2. R ve RStudio kurulumu (5 dakika)<\/a><\/li>\n\n\n\n
  3. Hemen bir analiz yapal\u0131m \u2014 t-testi<\/a><\/li>\n\n\n\n
  4. Kodu \u00e7al\u0131\u015ft\u0131rmak<\/a><\/li>\n\n\n\n
  5. Grafi\u011fi \u00e7izmek<\/a><\/li>\n\n\n\n
  6. Sonu\u00e7lar\u0131 yorumlamak<\/a><\/li>\n\n\n\n
  7. Perde arkas\u0131nda neler oldu?<\/a><\/li>\n\n\n\n
  8. S\u0131radaki ad\u0131mlar<\/a><\/li>\n<\/ol>\n\n\n\n

    Neden \u00e7o\u011fu R kursu sizi kaybediyor?<\/h2>\n\n\n\n

    R \u00f6\u011frenmeye \u00e7al\u0131\u015fan \u00e7o\u011fu ki\u015fi ayn\u0131 noktada tak\u0131l\u0131r. Kurs ba\u015flar, ilk ders “vekt\u00f6r nedir”, ikinci ders “liste nedir”, \u00fc\u00e7\u00fcnc\u00fc ders “data frame nedir”… Bir s\u00fcre sonra \u015fu soru kafan\u0131za tak\u0131l\u0131r: “Bunlar\u0131 neden \u00f6\u011freniyorum?”<\/em><\/p>\n\n\n\n

    Bu, asl\u0131nda zihnin do\u011fal bir tepkisi. \u0130nsan beyni anlam ba\u011flam\u0131 olu\u015fturmadan par\u00e7alar\u0131 birbirine ba\u011flayamaz. \u00d6nce b\u00fct\u00fcn\u00fc g\u00f6rmeniz gerekir.<\/strong> B\u00fct\u00fcn\u00fc g\u00f6rmeyen zihin, par\u00e7alar\u0131 bir yere koyamaz ve bunlar\u0131 k\u0131sa s\u00fcrede unutur.<\/p>\n\n\n\n

    Gestalt ilkesi<\/p>\n\n\n\n

    Alg\u0131 psikolojisinde Gestalt yakla\u015f\u0131m\u0131 \u015funu s\u00f6yler: insan zihni par\u00e7alar\u0131 \u00f6nce de\u011fil, b\u00fct\u00fcn\u00fc \u00f6nce alg\u0131lar. Bir bisiklet g\u00f6rd\u00fc\u011f\u00fcn\u00fczde \u00f6nce “bisiklet” g\u00f6r\u00fcrs\u00fcn\u00fcz, “iki tekerlek + sele + gidon” g\u00f6rmezsiniz. \u00d6\u011frenmede de bu b\u00f6yledir.<\/p>\n\n\n\n

    Bu yaz\u0131da sizi do\u011frudan \u00e7al\u0131\u015fan bir analizin i\u00e7ine ataca\u011f\u0131m. Birka\u00e7 sat\u0131r kod yazacaks\u0131n\u0131z, ger\u00e7ek bir istatistiksel sonu\u00e7 elde edeceksiniz, grafi\u011fi g\u00f6receksiniz. Analiz nas\u0131l yap\u0131l\u0131r sorusunun cevab\u0131 kendili\u011finden anlam kazanacak.<\/p>\n\n\n\n

    \n\n\n\n

    R ve RStudio kurulumu<\/h2>\n\n\n\n

    \u0130ki \u015fey kurman\u0131z gerekiyor. Birincisi R’nin kendisi, ikincisi R’yi rahat kullanman\u0131z\u0131 sa\u011flayan aray\u00fcz olan RStudio.<\/p>\n\n\n\n

    1 R’yi kurun<\/h3>\n\n\n\n

    cran.r-project.org<\/a> adresine gidin. \u0130\u015fletim sisteminize (Windows \/ Mac \/ Linux) g\u00f6re indirip kurun. Kurulum sihirbaz\u0131 ad\u0131m ad\u0131m y\u00f6nlendirir, hi\u00e7bir ayar\u0131 de\u011fi\u015ftirmenize gerek yok.<\/p>\n\n\n\n

    2 RStudio’yu kurun<\/h3>\n\n\n\n

    posit.co\/download\/rstudio-desktop<\/a> adresinden \u00fccretsiz “RStudio Desktop” s\u00fcr\u00fcm\u00fcn\u00fc indirin. Kurun ve a\u00e7\u0131n.<\/p>\n\n\n\n

    R mi a\u00e7\u0131yorum, RStudio mu?<\/p>\n\n\n\n

    Her zaman RStudio<\/strong>‘yu a\u00e7\u0131n. R arka planda \u00e7al\u0131\u015f\u0131r, siz RStudio \u00fczerinden onunla konu\u015fursunuz. R’yi do\u011frudan a\u00e7man\u0131za gerek yok.<\/p>\n\n\n\n

    RStudio ekran\u0131n\u0131 tan\u0131mak<\/h3>\n\n\n\n

    RStudio’yu ilk a\u00e7t\u0131\u011f\u0131n\u0131zda 3 b\u00f6lge g\u00f6r\u00fcrs\u00fcn\u00fcz: <\/p>\n\n\n\n

    B\u00f6lge<\/th>Ne i\u015fe yarar?<\/th><\/tr>
    Sol alt \u2014 Console<\/strong><\/td>Sonu\u00e7lar burada \u00e7\u0131kar.<\/td><\/tr>
    Sa\u011f \u00fcst \u2014 Environment<\/strong><\/td>Olu\u015fturdu\u011funuz veriler burada listelenir.<\/td><\/tr>
    Sa\u011f alt \u2014 Plots\/Files<\/strong><\/td>Grafikler, dosyalar, yard\u0131m sayfas\u0131 buradad\u0131r.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    Sol \u00fcstte File yazan yere t\u0131klay\u0131p New File -> New Script t\u0131klayarak yeni bir kod yazma defteri a\u00e7\u0131n. B\u00f6ylece ekran 4’e b\u00f6l\u00fcnecektir. <\/p>\n\n\n\n

    B\u00f6lge<\/th>Ne i\u015fe yarar?<\/th><\/tr>
    Sol \u00fcst \u2014 Script<\/strong><\/td>Kodunuzu buraya yazars\u0131n\u0131z. Kay\u0131t alt\u0131na al\u0131n\u0131r.<\/td><\/tr>
    Sol alt \u2014 Console<\/strong><\/td>Sonu\u00e7lar burada \u00e7\u0131kar.<\/td><\/tr>
    Sa\u011f \u00fcst \u2014 Environment<\/strong><\/td>Olu\u015fturdu\u011funuz veriler burada listelenir.<\/td><\/tr>
    Sa\u011f alt \u2014 Plots\/Files<\/strong><\/td>Grafikler, dosyalar, yard\u0131m sayfas\u0131 buradad\u0131r.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    <\/p>\n\n\n\n

    RStudio’da sol \u00fcst tarafa kodlar yaz\u0131l\u0131r, \u00e7al\u0131\u015ft\u0131r\u0131lmas\u0131 istenen kodlar se\u00e7ili hale getirilir ve kodlar\u0131n sa\u011f \u00fcst\u00fcndeki Run tu\u015funa bas\u0131larak \u00e7al\u0131\u015ft\u0131r\u0131l\u0131r. <\/p>\n\n\n\n

    \n\n\n\n

    Hemen bir analiz yapal\u0131m<\/h2>\n\n\n\n

    Sizi teknik detaylara bo\u011fmadan do\u011frudan bir analize atl\u0131yoruz. Senaryo \u015fu:<\/p>\n\n\n\n

    Senaryo<\/p>\n\n\n\n

    Bir ara\u015ft\u0131rmac\u0131 iki farkl\u0131 \u00f6\u011fretim y\u00f6ntemi uygulayan iki grup \u00f6\u011frencinin akademik ba\u015far\u0131 puanlar\u0131n\u0131 kar\u015f\u0131la\u015ft\u0131rmak istiyor. Grup A<\/strong> geleneksel anlat\u0131m y\u00f6ntemiyle, Grup B<\/strong> aktif \u00f6\u011frenme y\u00f6ntemiyle ders g\u00f6rd\u00fc. Her iki grupta da 15 \u00f6\u011frenci var. Gruplar aras\u0131nda anlaml\u0131 bir fark var m\u0131?<\/p>\n\n\n\n

    Bu soruyu cevaplamak i\u00e7in kullanaca\u011f\u0131m\u0131z analiz: ba\u011f\u0131ms\u0131z \u00f6rneklem t-testi.<\/strong><\/p>\n\n\n\n

    \u015eimdi RStudio’yu a\u00e7\u0131n, sol \u00fcstteki Script b\u00f6lmesine t\u0131klay\u0131n ve a\u015fa\u011f\u0131daki kodu yaz\u0131n (ya da kopyalay\u0131p yap\u0131\u015ft\u0131r\u0131n). Hen\u00fcz hi\u00e7bir \u015feyi anlamak zorunda de\u011filsiniz \u2014 sadece kodu \u00e7al\u0131\u015ft\u0131r\u0131n, ne oldu\u011funu birlikte g\u00f6rece\u011fiz.<\/p>\n\n\n\n

    Kodun tamam\u0131 \u2014 tek seferde \u00e7al\u0131\u015ft\u0131r\u0131n<\/h2>\n\n\n\n

    T\u00fcm kodu kopyalay\u0131p RStudio’ya sa\u011f \u00fcstteki yeni a\u00e7t\u0131\u011f\u0131m\u0131z kod yazma defterine yap\u0131\u015ft\u0131r\u0131n<\/p>\n\n\n\n

    # \u2500\u2500 Ad\u0131m 1: Verileri girin \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\ngrup_A <- c(72, 68, 75, 70, 65, 73, 69, 71, 67, 74,\n            70, 66, 72, 68, 71)\n\ngrup_B <- c(78, 82, 79, 85, 80, 77, 83, 81, 76, 84,\n            79, 82, 80, 78, 83)\n\n# \u2500\u2500 Ad\u0131m 2: Grup ortalamalar\u0131n\u0131 g\u00f6r\u00fcn \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\ncat(\"Grup A ortalamas\u0131:\", mean(grup_A), \"\\n\")\ncat(\"Grup B ortalamas\u0131:\", mean(grup_B), \"\\n\")\n\n# \u2500\u2500 Ad\u0131m 3: t-testini uygulay\u0131n \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\nsonuc <- t.test(grup_A, grup_B)\nprint(sonuc)\n\n# \u2500\u2500 Ad\u0131m 4: Grafi\u011fi \u00e7izin \u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\nveriler    <- c(grup_A, grup_B)\ngruplar    <- rep(c(\"Grup A\\nGeleneksel\", \"Grup B\\nAktif \u00d6\u011frenme\"), each = 15)\n\nboxplot(veriler ~ gruplar,\n        col    = c(\"#a8d5ba\", \"#1d6b4a\"),\n        main   = \"\u00d6\u011fretim Y\u00f6ntemi ve Ba\u015far\u0131 Puanlar\u0131\",\n        ylab   = \"Ba\u015far\u0131 Puan\u0131\",\n        border = \"#1d6b4a\")<\/code><\/pre>\n\n\n\n
    Kodu nas\u0131l \u00e7al\u0131\u015ft\u0131r\u0131rs\u0131n\u0131z?<\/p>\n\n\n\n
    T\u00fcm kodu se\u00e7in (Ctrl+A), ard\u0131ndan Ctrl+Enter<\/strong> tu\u015flar\u0131na bas\u0131n veya kod defterinin sa\u011f \u00fcst\u00fcndeki Run tu\u015funa bas\u0131n. Sol alttaki Console b\u00f6lmesinde sonu\u00e7lar, sa\u011f alttaki Plots b\u00f6lmesinde grafik belirecek.<\/p>\n\n\n\n
    \n\n\n\n
    Ekran\u0131n\u0131zda ne \u00e7\u0131kmas\u0131 gerekiyor?<\/h2>\n\n\n\n
    Console b\u00f6lmesinde \u015funa benzer bir \u00e7\u0131kt\u0131 g\u00f6receksiniz:<\/p>\n\n\n\n
    Grup A ortalamas\u0131: 70.07\nGrup B ortalamas\u0131: 80.47\n\n\tWelch Two Sample t-test\n\ndata:  grup_A and grup_B\nt = -10.832, df = 27.999, p-value = 4.44e-11\nalternative hypothesis: true difference in means is not equal to 0\n95 percent confidence interval:\n -12.42  -8.39\nsample estimates:\nmean of x mean of y \n    70.07     80.47<\/code><\/pre>\n\n\n\n
    Ve Plots b\u00f6lmesinde \u015f\u00f6yle bir kutu grafi\u011fi (boxplot) g\u00f6receksiniz:<\/p>\n\n\n\n
    Grafik \u00e7\u0131kmad\u0131 m\u0131?<\/p>\n\n\n\n
    Sa\u011f alt k\u00f6\u015fedeki “Plots” sekmesine t\u0131klay\u0131n. E\u011fer h\u00e2l\u00e2 yoksa kodu tam se\u00e7meden \u00e7al\u0131\u015ft\u0131rm\u0131\u015f olabilirsiniz \u2014 t\u00fcm sat\u0131rlar\u0131 se\u00e7ip tekrar deneyin.<\/p>\n\n\n\n
    Peki bu sonu\u00e7lar ne anlama geliyor?<\/h2>\n\n\n\n
    \u00c7\u0131kt\u0131y\u0131 birlikte okuyal\u0131m. Karma\u015f\u0131k g\u00f6r\u00fcn\u00fcyor ama asl\u0131nda \u00e7ok az bilgiye bakman\u0131z yeterli:<\/p>\n\n\n\n
    Grup A Ortalamas\u0131<\/p>\n\n\n\n
    70.07<\/p>\n\n\n\n
    Grup B Ortalamas\u0131<\/p>\n\n\n\n
    80.47<\/p>\n\n\n\n
    p de\u011feri<\/p>\n\n\n\n
    0.000<\/p>\n\n\n\n
    \u00c7\u0131kt\u0131da ne yaz\u0131yor?<\/th>Ne anlama geliyor?<\/th><\/tr>
    t = -10.832<\/code><\/td>t istatisti\u011fi. Fark\u0131n ne kadar b\u00fcy\u00fck oldu\u011funu standart sapma cinsinden s\u00f6yler. Negatif olmas\u0131 Grup A’n\u0131n daha d\u00fc\u015f\u00fck oldu\u011funu g\u00f6sterir \u2014 y\u00f6n\u00fcn \u00f6nemi yok, b\u00fcy\u00fckl\u00fc\u011f\u00fcne bak\u0131n.<\/td><\/tr>
    df = 27.999<\/code><\/td>Serbestlik derecesi. \u00d6rneklem b\u00fcy\u00fckl\u00fc\u011f\u00fcyle ilgili teknik bir de\u011fer.<\/td><\/tr>
    p-value = 4.44e-11<\/code><\/td>Bu \u00e7ok k\u00fc\u00e7\u00fck bir say\u0131: 0.0000000000444. Yani bu fark\u0131n tesad\u00fcften kaynaklanma olas\u0131l\u0131\u011f\u0131 y\u00fczde milyarda birden az.<\/strong> Fark istatistiksel olarak anlaml\u0131.<\/td><\/tr>
    95 percent confidence interval: -12.42, -8.39<\/code><\/td>Ger\u00e7ek fark\u0131n y\u00fczde 95 olas\u0131l\u0131kla 8.39 ile 12.42 puan aras\u0131nda oldu\u011funu s\u00f6yler. S\u0131f\u0131r\u0131 kapsamamas\u0131 fark\u0131n anlaml\u0131 oldu\u011funu destekler.<\/td><\/tr>
    mean of x = 70.07 \/ mean of y = 80.47<\/code><\/td>\u0130ki grubun ortalamalar\u0131. Grup B yakla\u015f\u0131k 10 puan daha y\u00fcksek.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    Sonucu tek c\u00fcmleyle nas\u0131l yazars\u0131n\u0131z?<\/p>\n\n\n\n
    “Aktif \u00f6\u011frenme y\u00f6ntemiyle ders g\u00f6ren \u00f6\u011frencilerin ba\u015far\u0131 puanlar\u0131 (M<\/em> = 80.47), geleneksel y\u00f6ntemle ders g\u00f6ren \u00f6\u011frencilere (M<\/em> = 70.07) k\u0131yasla istatistiksel olarak anlaml\u0131 bi\u00e7imde daha y\u00fcksektir, t<\/em>(28) = -10.83, p<\/em> < .001.”<\/p>\n\n\n\n
    Grafi\u011fi okumak<\/h2>\n\n\n\n
    Boxplot (kutu-b\u0131y\u0131k grafi\u011fi) be\u015f \u015feyi g\u00f6sterir:<\/p>\n\n\n\n
    Grafikte ne var?<\/th>Anlam\u0131<\/th><\/tr>
    Kutunun ortas\u0131ndaki \u00e7izgi<\/td>Medyan (ortanca de\u011fer)<\/td><\/tr>
    Kutunun alt ve \u00fcst kenarlar\u0131<\/td>De\u011ferlerin orta %50’si (1. ve 3. \u00e7eyrek)<\/td><\/tr>
    B\u0131y\u0131klar (\u00e7izgiler)<\/td>U\u00e7 de\u011ferlerin d\u0131\u015f\u0131ndaki geni\u015f aral\u0131k<\/td><\/tr>
    Tek noktalar<\/td>Ayk\u0131r\u0131 de\u011ferler (varsa)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
    Grafikte Grup B kutusunun tamam\u0131n\u0131n Grup A’n\u0131n \u00fczerinde oldu\u011funu g\u00f6receksiniz. \u0130ki grup aras\u0131ndaki fark g\u00f6zle bile bellidir.<\/p>\n\n\n\n
    \n\n\n\n
    Perde arkas\u0131nda neler oldu? (Merak edenler i\u00e7in)<\/h2>\n\n\n\n
    \u015eimdiye kadar hi\u00e7bir teknik a\u00e7\u0131klama yapmadan analizi bitirdik. Ama art\u0131k b\u00fct\u00fcn\u00fc g\u00f6rd\u00fc\u011f\u00fcn\u00fcze g\u00f6re par\u00e7alar\u0131 a\u00e7\u0131klayabiliriz.<\/p>\n\n\n\n
    c() neydi?<\/h3>\n\n\n\n
    c()<\/code> fonksiyonu say\u0131lar\u0131 bir araya toplar. R’de buna “vekt\u00f6r” denir. Ama bunu bilmeden de kulland\u0131n\u0131z \u2014 \u00e7\u00fcnk\u00fc ne i\u015fe yarad\u0131\u011f\u0131n\u0131 ba\u011flamdan g\u00f6rd\u00fcn\u00fcz.<\/p>\n\n\n\n
    Rc() nedir?<\/p>\n\n\n\n
    puanlar <- c(72, 68, 75)\n# Bunu \u015fu \u015fekilde okuyun:\n# \"puanlar ad\u0131nda bir \u015fey olu\u015ftur, i\u00e7ine 72, 68, 75 koy\"<\/code><\/pre>\n\n\n\n
    <- neydi?<\/h3>\n\n\n\n
    R’deki atama operat\u00f6r\u00fc. “Sol taraftaki isme, sa\u011f taraftaki de\u011feri ver” demek. puanlar <- c(72, 68, 75)<\/code> dedi\u011finizde “puanlar” adl\u0131 bir nesne olu\u015fturdunuz. Sa\u011f \u00fcstteki Environment b\u00f6lmesinde g\u00f6rebilirsiniz.<\/p>\n\n\n\n
    t.test() otomatik olarak ne yapt\u0131?<\/h3>\n\n\n\n
    R’de t.test()<\/code> fonksiyonu iki grubu al\u0131r, aralar\u0131ndaki fark\u0131 hesaplar, t istatisti\u011fini bulur, serbestlik derecesini hesaplar, p de\u011ferini hesaplar ve g\u00fcven aral\u0131\u011f\u0131n\u0131 hesaplar. Bunu elle yapmak saatler al\u0131r. R tek sat\u0131rda yapar.<\/p>\n\n\n\n
    rep() neydi?<\/h3>\n\n\n\n
    Grafik i\u00e7in grup etiketleri olu\u015fturuyorduk. rep(\"Grup A\", each = 15)<\/code> “Grup A” yaz\u0131s\u0131n\u0131 15 kez tekrarl\u0131yor demektir. 15 puan\u0131n 15 etikete ihtiyac\u0131 var.<\/p>\n\n\n\n
    Art\u0131k “vekt\u00f6r nedir?” sorusunun cevab\u0131 anlaml\u0131<\/p>\n\n\n\n
    Bir kurs “vekt\u00f6r, ayn\u0131 t\u00fcrden elemanlar\u0131n s\u0131ral\u0131 bir koleksiyonudur” dedi\u011finde bunu soyut bulurdunuz. Ama art\u0131k grup_A<\/code>‘y\u0131 kendiniz olu\u015fturdunuz. Vekt\u00f6r, i\u015fte o \u2014 puanlar\u0131n topland\u0131\u011f\u0131 liste. Bundan sonra bu kavram\u0131 unutmazs\u0131n\u0131z.<\/p>\n\n\n\n
    \n\n\n\n
    S\u0131radaki ad\u0131mlar<\/h2>\n\n\n\n
    Bu analizi yapt\u0131ysan\u0131z art\u0131k R konusunda \u015funlar\u0131 biliyorsunuz:<\/p>\n\n\n\n