3.4.2 iisampuli Non-linokuba: weighting
Kunye neesampuli non-ngokuqinisekileyo, namatye ungenza ingenzeki iimposiso okubangelwa inkqubo isampuli kucingelwa.
Ngendlela efanayo ukuba abaphandi kuzilinganisela iimpendulo ezisuka iisampuli ngokuqinisekileyo, bona kwakhona kuzilinganisela iimpendulo ezisuka iisampuli non-ezinokwenzeka. Ngokomzekelo, njengenye indlela iCPS, masithi ukuba kubekwa iintengiso kwilaphu amawaka kwiiwebhsayithi ukuqesha nxaxheba ungasisishwankathelo ukuqikelela izinga lentswela. Ngokuqhelekileyo, ubuya sokuthandabuza ukuba kuthetha ezilula isampuli yakho kuba ingqikelelo ezilungileyo izinga lentswela. ibeka mhlawumbi kuba ucinga ukuba abanye abantu kungenzeka ukuba zizalise isaveyi yakho kunezinye. Umzekelo, abantu musa ukuchitha ixesha elininzi kwi-web abanakufane ukugqibezela uphando lwakho.
Njengoko siye sabona kwicandelo lokugqibela, nangona kunjalo, ukuba siyazi indlela ekhethiweyo-njengoko isampulu ntoni ezinokwenzeka iisampuli-ngoko ungenza ingenzeki iimposiso okubangelwa inkqubo isampulu. Ngelishwa, xa esebenza iisampuli non-ngokuqinisekileyo, asazi indlela ekhethiweyo isampulu. Kodwa ke, sinako ukwenza iingqikelelo malunga nenkqubo isampuli uze isicelo weighting ngendlela efanayo. Ukuba le kokucingelwayo zichanekile, ngoko ukulinganiswa uya kuwulungisa kwezithintelo okubangelwa inkqubo isampulu.
Ngokomzekelo, cinga ukuba njengempendulo iintengiso zakho ibhena, wena bagaywa 100,000 abaphenduli. Noko ke, musani ukuba aba 100,000 abaphendule isampuli elula random abadala American. Enyanisweni, xa uthelekisa abaphenduli yakho abemi US, uya kufumanisa ukuba abantu abasuka kwamanye amazwe (umzekelo, New York) abantu phezu-zimelwe kwaye ukuba ezinye States (umzekelo, Alaska) abamelwanga ngokulingana. Ngenxa yoko, izinga lentswela kwiisampula yakho kungenzeka ukuba uqikelelo olubi izinga ngqesho ekujoliswe kubo.
Enye indlela ukukhulula nelizwi kwenzeka inkqubo isampulu ukuba abele amatye ukuba umntu ngamnye; iintsimbi abasezantsi abantu States ukuba kwama-amelweyo kwisampulu (umzekelo, New York) kunye namatye ephakamileyo abantu lithi baphantsi-amelweyo kwisampulu (umzekelo, Alaska). Ngokungakumbi, ubunzima ngenxa ummangalelwa nganye enxulumene yolwaphulo kwi isalamane sakho isampuli ukuxhaphaka yabo bebonke US. Le nkqubo weighting kuthiwa post-abahlulwe, yaye ingcamango ukucingisisa kufuneka kunikhumbuza umzekelo kwiCandelo 3.4.1 apho abaphenduli ukusuka Rhode Island banikwa ubunzima ngaphantsi abaphenduli eCalifornia. Post-abahlulwe ifuna ukuba uyazi ngokwaneleyo ukubeka abaphenduli bakho ngokwamaqela kwanokulwazi ngokomlinganiselo lwabantu ekujoliswe kwiqela ngalinye.
Nangona umlinganiselo ngeesampulu lemizuzu kunye isampuli non-okuba ngabona ngokwezibalo mnye (jonga kwisihlomelo zobugcisa), abasebenza kakuhle kwiimeko ezahlukeneyo. Ukuba umphengululi kunethuba isampulu ofezekileyo (oko kukuthi, akukho imposiso iTshathi akukho non-impendulo), ngoko weighting uya kuvelisa uqikelelo cala zonke iimpawu kuzo zonke iimeko. Esi siqinisekiso ngamandla theoretical nto ukulwela iisampulu ezinokwenzeka akayifumana nomtsalane kangaka. Kwelinye icala, iisampuli non-linokuba weighting uya kuvelisa kuphela iingqikelelo cala zonke iimpawu ukuba nelona impendulo minye wonke umntu kwiqela ngalinye. Ngamanye amazwi, ecamngca kumzekelo wethu, esebenzisa post-abahlulwe uya kuvelisa uqikelelo cala ukuba wonke eNew York linokuba efanayo inxaxheba kwaye wonke Alaska ubani linokuba efanayo inxaxheba njalo-njalo. Le nkkolelo kuthiwa yohlobo-impendulo-nelona-ngaphakathi-amaqela kwinkolelo, kwaye idlala indima ephambili ukwazi ukuba post-abahlulwe zizakusebenza kakuhle iisampuli non-ezinokwenzeka.
Ngelishwa, kumzekelo wethu, yohlobo-impendulo-nelona-ngaphakathi-amaqela kwingcinga Kubonakala kungenakwenzeka ukuba kuyinyaniso. Oko kukuthi, kubonakala kungenakwenzeka ukuba wonke Alaska ubani linokuba efanayo ukuba kuphando yakho. Kodwa ke, kukho amanqaku amathathu Kubalulekile ukuba sikhumbule malunga post-abahlulwe, konke oku kwenza kube ngathi ethembisa ngakumbi.
Okokuqala, yohlobo-impendulo-nelona-ngaphakathi-amaqela kwingcinga uba iyavakala ngakumbi njengoko inani lamaqela ukunyuka. Ke, abaphandi aphelela kumaqela nje ngokusekelwe njengomlinganiso yokoqobo. Ngokomzekelo, siya Ndizakwenza amaqela esekelwe karhulumente, ubudala, isini, kunye nomgangatho wemfundo. Kubonakala kusengqiqweni ukuba kukho nelona impendulo yohlobo ngaphakathi kwiqela 18-29, nabakhonzazana, kwikholeji abanezidanga abahlala Alaska kunokuba ngaphakathi kwiqela bonke abantu abahlala Alaska. Ngoko ke, njengoko inani lamaqela ezisetyenziselwa ukunyuswa post-abahlulwe, sinoluvo ezifunekayo ukuxhasa baba isengqiqweni. Ngokwemeko le Eneneni, kubonakala ngathi Abaphengululi ufuna ukwenza inani elikhulu lamaqela ngenxa post-abahlulwe. Kodwa ke, njengoko inani lamaqela ukunyuka, abaphandi Ndingena ingxaki eyahlukileyo: sparsity data. Ukuba kukho inani elincinane kuphela labantu kwiqela ngalinye, ngoko ke uqikelelo ziya kuba ezinonok-, yaye kwimeko ngokugqithiseleyo apho kukho iqela akukho abaphenduli, ngoko post-abahlulwe iyonakala ngokupheleleyo. Kukho iindlela ezimbini kule enixabana semvelo phakathi badala ye homogeneous- impendulo-Ukuthambekela-ngaphakathi-amaqela kwingcinga kwaye imfuno ngobukhulu sample elifanelekileyo kwiqela ngalinye. Enye indlela kukuba bafudukele imodeli nobunzima kakhulu statistical yokubala iintsimbi yaye elinye lokuqokelela, isampulu ezahlukeneyo kakhulu, nto leyo inceda ukuqinisekisa ubungakanani sample elifanelekileyo kwiqela ngalinye. Ke, maxa wambi abaphandi kwenza zombini, njengoko ndiza zisichazela ngakumbi ngezantsi.
Ukuhlolisisa wesibini xa usebenza post-abahlulwe evela iisampuli non-linokuba kukuba yohlobo-impendulo-Ukuthambekela-ngaphakathi-amaqela ngqikelelo sele yenziwe rhoqo xa kuhlalutywa iisampulu ezinokwenzeka. Isizathu sokuba le ngqikelelo efunekayo iisampulu linokuba kwi ndlela kukuba iisampulu linokuba kuba non-impendulo, yaye indlela zixhaphakileyo ngenxa yokwehla non-impendulo zasemva-abahlulwe njengoko kuchaziwe apha ngasentla. Kakade ke, ngenxa nje abaphandi abaninzi ukwenza uqikelelo othile akuthethi ukuba kufuneka bawenze. Kodwa ke, oko kuthetha ukuba xa bethelekisa iisampuli non-linokuba ukuba iisampulu okwenzeka kwindawo yokusebenza, kufuneka sikhumbule ukuba zombini zixhomekeke kokucingelwayo kwaye ulwazi ezincedisayo ukuze avelise uqikelelo. Kwimeko ezininzi eziyinyani, akukho nje akukho ndlela kwingcinga-ukhululekile ukuba inzuzo.
Okokugqibela, ukuba Wazazi enye uqikelelo ingakumbi bethu-Umzekelo izinga lentswela-ngoko ufuna imeko ithambile yohlobo-impendulo-Ukuthambekela-ngaphakathi-amaqela ngokucinga. Ingakumbi, ukuba awufuni ukuba ukucinga ukuba wonke umntu impendulo Ukuthambekela efanayo, kufuneka kuphela sicinge ukuba akukho unxulumano phakathi impendulo Ukuthambekela kwaye izinga lentswela kwiqela ngalinye. Kakade ke, nokuba le meko ebuthathaka angabambeki kwezinye iimeko. Ngokomzekelo, cinga oqikelela masilivakalise baseMerika ukuba enze umsebenzi ngokuzithandela. Ukuba abantu abenza umsebenzi ongabhatalwayo kusenokwenzeka ukuba uvume ukuba ube uphando, ngoko abaphandi ngokucwangcisiweyo phezu-ukuqikelela ubungakanani njengetsha, nokuba benza uhlengahlengiso post-abahlulwe, ngenxa yokuba uye wabonisa empirically yi Abraham, Helms, and Presser (2009) .
Njengoko besenditshilo ngaphambili, iisampulu non-linokuba zibonwa kunye kukulumka kakhulu zizazinzulu zentlalo, ngokuyinxenye ngenxa yendima yabo kwezinye yokusilela ezininzi iintloni ngemihla ekuqaleni uphando uphando. Umzekelo ocacileyo ikude kangakanani baye iisampuli non-linokuba thina ke uphando Wei Wang, uDavide Rothschild, Sharad Goel, noAndreya Gelman ukuba wachacha ngokuchanekileyo isiphumo 2012 US unyulo kusetyenziswa iisampula non-amathuba lwabasebenzisi American Xbox -oko isampulu ukwenza non-random Melika (Wang et al. 2015) . Abaphandi abafu- abaphenduli kwinkqubo midlalo Xbox, njengoko unokulindela, isampuli Xbox elibhalwe ngokumileyo inkunzi goso abaselula: 18 - kuma-29 kunyaka abumba 19% labavoti kodwa 65% yamanqaku e-Xbox lwesampulu namadoda abumba 47% labavoti kwaye 93% ye Xbox isampulu (Figure 3.4). Ngenxa yezi yocalu ngamandla ngokwedemografi, iinkcukacha Xbox ekrwada yaba luphawu amahlwempu returns zonyulo. Oku yaqikelela uloyiso olomeleleyo Mitt Romney phezu Barack Obama. Kwakhona, oku ngomnye umzekelo iingozi, iisampulu ekrwada non-linokuba unadjusted kwaye embhoxo yokuFunda Digest fiasco.
Isazobe 3.4: Amanani lwabaphenduleyo Wang et al. (2015) . Ngenxa abaphenduli baye bagaywa ukusuka Xbox, bathi kusenokwenzeka ukuba sisebatsha yaye kusenokwenzeka ukuba abe yindoda, xa kuthelekiswa lwabavoti kunyulo 2012.
Nangona kunjalo, Wang kunye nabalingane babelazi ezi ngxaki kwaye izame ngokwelitye abamangalelwa ukulungisa le nkqubo isampulu. Ingakumbi, ayesebenzisa uhlobo nobunzima kakhulu yesithuba-abahlulwe mna ndandinixelele. Kubalulekile ukufunda isuntswana ngakumbi indlela yabo ngenxa yokuba yakha ncebiso malunga post-abahlulwe, kunye nenguqulelo ethile Wang noogxa ezisetyenzisiweyo yenye iindlela imincili kwi iisampuli non-ezinokwenzeka weighting.
Kumzekelo yethu ezilula malunga ukuqikelela ngqesho kwiCandelo 3.4.1, siya wabahlula abantu ngokwamaqela ngokusekelwe imo yokuhlala. Ngokwahlukileyo koko, Wang kunye nabalingane wabahlula lwabemi ngokwamaqela 176.256 kuchaziwe: isini (iindidi 2), uhlanga (iindidi 4), ubudala (iindidi 4), imfundo (iindidi 4), karhulumente (iindidi 51), ID iqela (3 iindidi), ekucingwa (iindidi 3) kuvota-2008 (iindidi 3). Kumaqela amaninzi, abaphandi wayeqinisekile ukuba kuza kuba ngakumbi kusenokwenzeka ukuba ngaphakathi kwiqela ngalinye, impendulo Ukuthambekela waba uncorrelated ngenkxaso Obama. Okulandelayo, kunokuba kusakhiwa iintsimbi ngamnye-level, njengoko wenzayo kumzekelo wethu, Wang kunye nabalingane lasebenzisa imodeli entsonkothileyo ukuqikelela inani labantu kwiqela ngalinye ukuba uvotele Obama. Okokugqibela, bahlanganisa ezi uqikelelo iqela inkxaso ubungakanani eyaziwayo yeqela ngalinye ukuze avelise inqanaba eliqikelelweyo ngokubanzi kwenkxaso. Ngamanye amazwi, xa wagawulwa ukuya abemi ngokwamaqela ahlukeneyo, kuqikelelwa inkxaso Obama kwiqela ngalinye, waza wathabatha elilinganiswe ngokomyinge uqikelelo qela ukuvelisa jikelele uqikelelo.
Ngoko ke, umngeni omkhulu indlela yabo ukuqikelela inkxaso Obama ngalinye kula maqela 176.256. Nangona lenjongo yabo kwakubandakanya 345.858 nxaxheba esisodwa, inani elikhulu yimigangatho lonyulo unyulo, kwakukho amaninzi amaqela, abaninzi apho Wang noogxa beziphantse akukho mpendulo. Ngoko ke, ukuqikelela inkxaso kwiqela ngalinye ayesebenzisa njengobuchule ebizwa eguqulweyo multilevel iposi-abahlulwe, research ebesaziwa umnxeba uMnu P. Ngokwesiseko, ukuqikelela inkxaso Obama ngaphakathi kwiqela elithile, uMnu P. amadama ulwazi ezininzi amaqela ngokusondeleyo ezinxulumene. Ngokomzekelo, cinga nocelomngeni nokuqikela inkxaso Obama phakathi nesiPhuthukezi nemazi,, phakathi kweminyaka 18-29 ubudala, owathi abaphumelele kwikholeji, abo Democrats obhalisiweyo, owathi-ukuchonga njengoko Ukwenza, ngubani wavotelwa Obama ngo-2008 Le liqela kakhulu, ngqo kakhulu, kwaye kunokwenzeka ukuba akukho mntu kwisampulu nezi mpawu. Ngoko ke, ukuba benze iingqikelelo malunga neli qela, uMnu P. amadama kunye iqikelela ebantwini kumaqela efana kakhulu.
Ukusebenzisa esi sicwangciso uhlalutyo, Wang kunye nabalingane bakwazi ukusebenzisa Xbox non-isampulu ukuqikelela ngokusondeleyo kakhulu inkxaso ngokubanzi ukuba Obama owalwamkelayo kunyulo 2012 (Figure 3.5). Enyanisweni iingqikelelo zabo yechanekileyo ngaphezulu kwesongezelelo ye ngokweentloko izimvo zoluntu. Ngoko ke, kule meko, weighting-ngqo kuMnu P.-kubonakala ukuba benze umsebenzi olungileyo ulungisa ucalu kwi data non-linokuba; nocalu ezibonakalayo xa ujonga uqikelelo ukusuka data Xbox unadjusted.
Isazobe 3.5: Uqikelelo ukusuka Wang et al. (2015) . Unadjusted Xbox isampulu wavelisa uqikelelo ayichananga. Kodwa, Xbox isampuli weighted wavelisa uqikelelo ukuba yechanekileyo ngaphezu avareji uphando ngomnxeba ezinokwenzeka-based.
Kukho izinto ezimbini eziphambili ukusuka ukufunda Wang kunye noogxa. Okokuqala, iisampulu non-linokuba unadjusted kunokukhokelela uqikelelo ezimbi; le isifundo ukuba abaphandi abaninzi nalivayo ngenxa engaphambili. Noko ke, isifundo sesibini kukuba iisampuli non-ngokuqinisekileyo, xa kulinganiselwa kakuhle, ndingekawuboni ukuvelisa uqikelelo buntlana. Enyanisweni, uqikelelo zabo yechanekileyo ngaphezu uqikelelo ukusuka pollster.com, omndilili ngokweentloko ngaphezulu unyulo yemveli.
Okokugqibela, kukho imida kubalulekile oko sinokukufunda kolu phononongo ethile. Nje ngokuba post-abahlulwe wasebenza kakuhle kule meko, akukho siqinisekiso sokuba kuya kusebenza kakuhle kwezinye iimeko. Enyanisweni, unyulo mhlawumbi omnye izicwangciso ilula kuba Abaphandi belufunda unyulo phantse 100 iminyaka, kukho ingxelo rhoqo (sikwazi ukubona ukuba ngubani na ophumelela kunyulo), kunye nokuchongwa iqela neempawu demographic ke okuza noko ngokuvota. Kweli nqanaba, asinabo ithiyori eqinileyo namava reseach ukwazi xa utshintsho wobunzima ukuba iisampuli non-linokuba uya kuvelisa uqikelelo oluchanileyo ngokwaneleyo. Enye into ecacileyo, Noko ke, ukuba banyanzelwa ukuba basebenze kunye iisampuli non-ngokuqinisekileyo, ngoko ke kukho isizathu sokukholelwa ukuba ngawoqikelelo oluhlaziyiweyo kuya kuba ngcono noqikelelo non-mali.
