3.4.1 Amathuba izibonelo zalokho: iqoqo idatha kanye nedatha analysis
Izinsimbi kungakuqinisa ukuhlehlisa Ukuhlanekezelwa ngamabomu okubangelwa inqubo izibonelo zalokho.
Amasampula Amathuba yilawo lapho bonke abantu babe owaziwa, non-zero ematfuba iinthombe, futhi elula ematfuba ukusampula design ilula amasampuli okungahleliwe lapho umuntu ngamunye okungenzeka alinganayo iinthombe. Ngesikhathi Abazinikele bakhethwa nge elula amasampuli okungahleliwe ngokubulawa ephelele (isib, hhayi phutha Ukusabalala futhi akukho non-impendulo), ukulinganisa kuqondile ngoba isampula ngeke-edlulayo-kube version amancane labantu.
Simple amasampuli okungahleliwe kuyaqabukela Nokho elisetshenziswa umkhuba,. Kunalokho, abacwaningi ngenhloso khetha abantu abane Ematfuba ngokungalingani iinthombe ukuze kuncishiswe izindleko bese andise nokunemba. Lapho abacwaningi ngenhloso ukhetha abantu abane Ematfuba ezahlukene iinthombe, khona-ke izinguquko ezidingekayo ukuhlehlisa ukuhlanekezela okubangelwa inqubo izibonelo zalokho. Ngamanye amazwi, indlela thina kuvame kusuka isampula kuxhomeke endleleni isampula sikhethwe.
Ngokwesibonelo, i-Current Population Survey (CPS) isetshenziswa nguhulumeni wase-United States ukulinganisa izinga lokungasebenzi. Inyanga ngayinye abantu ababalelwa ku-100-000 Kuxoxwa, kungaba ubuso nobuso noma ngocingo, futhi imiphumela ezisetshenziswa emasimini ukukhiqiza ukudla kulinganiselwa labangasebenzi liphezulu. Ngoba uhulumeni efisa ukulinganisa izinga lokungasebenzi esimweni ngasinye, it ayikwazi ukwenza isampula elula okungahleliwe abadala ngoba lokho kwakuyobonisa ukuthela wabaphenduli ezimbalwa kakhulu emazweni ne idlanzana (isib, Rhode Island) kanye eziningi kakhulu kusukela uthi imiphakathi emikhulu (isib , California). Kunalokho, lo CPS amasampula abantu ahlukene ngamazinga angefani, inqubo ebizwa ngokuthi izibonelo zalokho wakubo nge ematfuba ngokungalingani Ukukhetha. Ngokwesibonelo, uma CPS wayefuna wabaphenduli 2,000 state ngamunye, bese abadala Rhode Island kuzodingeka mayelana ephakeme izikhathi 30 ematfuba iinthombe kunabantu abadala eCalifornia (Rhode Island: 2,000 wabaphenduli ngamunye 800,000 abadala vs California: 2,000 wabaphenduli ngamunye 30.000.000 abadala). Njengoba sizobona kamuva, lolu hlobo izibonelo zalokho nge ematfuba ukungalingani kwenzeka imithombo inthanethi idatha kakhulu, kodwa ngokungafani CPS, lo mshini izibonelo zalokho is ngokuvamile engaziwa noma elawulwa yiyo umcwaningi.
Njengoba sazi sampling yayo design, the CPS akuyona ngokuqondile ummeleli we-US, lihlanganisa abantu abaningi kakhulu Rhode Island Imbalwa kakhulu basuka eCalifornia. Ngakho-ke, kungaba ubuwula ukulinganisa izinga lokuntuleka kwemisebenzi ezweni ne izinga lokuntuleka kwemisebenzi isampula. Esikhundleni kusho isampula, kungcono ukuthatha kwesamba asho, lapho i-akhawunti izisindo lokuthi abantu kusukela Rhode Island ayemaningi amathuba okuba zifakwe kuka abantu basuka eCalifornia. Ngokwesibonelo, umuntu ngamunye waseCalifornia bekuyoba upweighted- they bekuyoba ukubala ngaphezulu balinganisela-futhi umuntu ngamunye kusukela Rhode Island yayiyobizwa downweighted-babeyoqhubeka ukubala kancane balinganisela. Empeleni, unikezwa zezwi ukuba abantu ukuthi mancane kakhulu amathuba ukuze ufunde kabanzi mayelana.
Lesi sibonelo ithoyizi siveza iphuzu elibalulekile kodwa evame uqondwa: isampula akudingeki ukuba ube version amancane labantu ukuze akhiqize tilinganiso ezinhle. Uma Akwanele mayelana nendlela idatha eqoqwe yaziwa, lolo lwazi ke angasetshenziswa lapho senza ezakhishwa isampula. Le ndlela ngisanda echazwe-nokuthi ngichaze izibalo kule lobuchwepheshe isithasiselo saleli Bhayibheli-ewela ngqó ngaphakathi the classic ematfuba izibonelo zalokho uhlaka. Manje, Ngizokukhombisa kanjani ukuthi umqondo ofanayo singasetshenziswa amasampula non-ematfuba.
