Thaum peb ua piv txwv nrog kev hloov pauv, ob tus qauv qhov tseem ceeb yog ywj siab Xyaum, qhov no txhais tau tias qhov peb tau txais ntawm thawj tus tsis cuam tshuam qhov peb tau txais thib ob. Ua lej, qhov no txhais tau hais tias qhov sib txawv ntawm ob yog xoom. Hauv kev ua piv txwv yam tsis muaj kev hloov pauv, ob qho piv txwv qhov tseem ceeb tsis muaj kev ywj pheej.
Koj puas yuav coj mus kuaj nrog lossis tsis hloov?
Piv txwv li, yog tias ib tus kos ib qho piv txwv yooj yim xws li tsis muaj ib chav tshwm sim ntau dua ib zaug hauv tus qauv, tus qauv yog kos yam tsis hloov. Yog tias ib chav tsev tuaj yeem tshwm sim ib lossis ntau zaus hauv cov qauv, ces tus qauv raug kos nrog hloov.
Vim li cas thiaj tuaj yeem ua piv txwv nrog kev hloov pauv tsis zoo?
Sampling nrog hloov yog tsawg dua qhov piv txwv yam tsis hloov(piv txwv li, qhov sib txawv ntawm tus kwv yees yuav loj dua). Txawm li cas los xij, thaum qhov piv txwv feem f=n / M me me, qhov tshwm sim uas ib chav tsev yuav tshwm sim ob zaug hauv cov qauv kuj yog me me.
Nws txhais li cas thaum kuaj ua tiav nrog kev hloov?
Thaum chav ntsuas ntsuas tau raug rho tawm los ntawm cov pej xeem tsawg thiab xa rov qab mus rau cov pej xeem, tom qab nws cov yam ntxwv tau raug sau tseg, ua ntej chav ntsuas tom ntej tau kos, sampling yog hais tias "nrog hloov ".
Puas random sampling ua tiav nrog hloov?
Sampling raug hu nrog hloov thaum ib chav xaiv ntawm random los ntawm cov pej xeem raug xa rov qab mus rau cov pej xeem thiab tom qab ntawd lub ntsiab thib ob raug xaiv ntawm random Thaum twg ib chav xaiv, tus cov pejxeem muaj tag nrho cov tib units, yog li ib chav yuav raug xaiv ntau dua ib zaug.
