4.1 Gabatarwa
A cikin hanyoyin rufe ya zuwa yanzu a cikin wannan littafi-lura hali (Babi na 2) da kuma yin tambayoyi (Babi na 3) -researchers tattara bayanai game da abin da aka halitta da ke faruwa a duniya. The m rufe a wannan babi-guje gwajen-ne fundamentally daban-daban. A lokacin da masu bincike gudanar da gwaje-gwajen, suka tsare baki a duniya ya halicci data da aka fi dacewa dace da amsa tambayoyi game da dalilin-da-sakamako dangantaka.
Ka saukar da-da-sakamako tambayoyi ne sosai na kowa a social bincike, kuma misalai hada tambayoyi kamar Ainihi kara malamai albashi ƙara dalibi koyo? Mene ne sakamakon m ijara a kan aikin rates? Ta yaya aiki mai nema ta tseren qaddamar da ta samu damar na samun aiki? Bugu da kari wadannan baro-baro causal tambayoyi, wani lokacin sa-da-sakamako tambayoyi ne a fakaice a mafi general tambayoyi game maximization wasu yi awo. Alal misali, tambaya "Me launi button zai kara gudunmawa a kan NGO website site?" Shi ne ainihin kuri'a tambayoyi game da sakamako daban-daban button launuka a kyaututtuka.
Daya hanyar amsa hanyar-da-sakamako tambayoyi ne da ya nemi alamu a data kasance bayanai. Alal misali, ta amfani da data daga dubban makarantu, za ka iya lissafta cewa dalibai koyi a makarantu da bayar da high malami albashi. Amma, yaya wannan hulda nuna cewa mafi girma albashi sa dalibai don ƙarin koyo? Hakika ba. Schools inda malamai aikatãwa more iya zama daban-daban da yawa a cikin hanyoyi. Alal misali, dalibai a makarantu da high malami albashi zai zo daga arziki iyalansu. Saboda haka, abin da kama wani sakamako na malamai iya kawai zo daga gwada daban-daban na dalibai. Wadannan bambance-bambance tsakanin unmeasured dalibai suna kira confounders, kuma a general, da yiwuwar confounders wreaks halaka a bincike ikon amsa hanyar-da-sakamako tambayoyi da neman alamu a data kasance bayanai.
Daya warware matsalar confounders ne ga kokarin yin adalci kwatancen da daidaitawa for Fitowan bambance-bambance tsakanin kungiyoyin. Alal misali, za ka iya iya download dukiya haraji bayanai daga wata dama gwamnatin yanar. Sa'an nan, za ka iya kwatanta dalibi yi a makarantu, inda home farashin m amma malami albashi ne daban-daban, da kuma har yanzu kana iya samun cewa dalibai koyi a makarantu da hakan malami albashi. Amma, har yanzu akwai mutane da yawa m confounders. Wata kila da iyaye na wadannan dalibi ya bambanta a cikin mataki na ilimi ko watakila makarantu bambanta a cikin kusanci da jama'a dakunan karatu ko watakila da makarantu da hakan malami albashi ma da hakan albashi sune kuma babba albashi, ba malami albashi, shi ne ainihin abin da aka kara dalibi koyo. Za ka iya kokarin gwada wadannan wasu dalilai da, amma jerin yiwu confounders ne da gaske m. A da yawa yanayi, ku kawai ba zai iya auna da kuma daidaita ga dukan yiwu confounders. Wannan dabarar iya kai ka zuwa yanzu.
A mafi alhẽri warware matsalar confounders ne a guje gwaje-gwajen. Gwaje-gwajen da masu bincike taimaka don motsawa a hayin huldodi a halitta abin da ke faruwa data domin dogara amsa hanyar-da-sakamako tambaya. A cikin analog shekaru, gwaje-gwajen sun sau da yawa logistically wuya da kuma tsada. Yanzu, a cikin dijital shekaru, tafarkin constraints suna hankali Fading bãya. Ba wai kawai shi ne ya fi sauƙi yi gwaje-gwajen da masu bincike kamar waɗanda suka yi a baya, shi ne a yanzu zai yiwu a gudanar da sabon iri gwaje-gwajen.
A abin da Na rubuta zuwa yanzu Na jima ina a bit sako-sako da a harshen, amma yana da muhimmanci a rarrabe tsakanin abubuwa biyu: gwaje-gwajen da yi da ka sarrafawa gwaje-gwajen. A wani gwajin wani mai bincike shãmakacẽwa a duniya, sa'an nan kuma ƙaddara wani sakamako. Na kuma sha jin wannan dabarar aka bayyana a matsayin "perturb kuma suka tsayar." Wannan dabarun sosai tasiri a cikin halitta sciences, amma a kiwon lafiya da kuma zaman takewar kimiyya, akwai wani m da aiki mafi alhẽri. A cikin wata yi da ka sarrafawa gwajin wani mai bincike shãmakacẽwa ga wasu mutane da ba don wasu, da kuma, kafofin yada, da bincike yanke shawarar abin da mutane sama da baki da randomization (misali, flipping tsabar kudin). Wannan hanya tabbatar da cewa gwaje-gwajen da yi da ka sarrafawa halitta gaskiya kwatantawa tsakanin kungiyoyin biyu: daya da ya karbi baki da kuma daya da cewa yana da ba. A wasu kalmomin, yi da ka sarrafawa gwajen ne a warware matsalolin da confounders. Duk da muhimmanci bambance-bambance tsakanin gwaje-gwajen da yi da ka sarrafawa gwaje-gwajen, zamantakewa bincike sau da yawa amfani da wadannan sharuddan interchangeably. Zan bi wannan al'ada, amma, a wani maki, zan karya da al'ada jaddada darajar yi da ka sarrafawa gwaje-gwajen a kan gwaje-gwajen ba tare da randomization da iko kungiyar.
Yi da ka sarrafawa gwaje-gwajen sun tabbatar da su zama mai iko hanyar koyi game da zamantakewa duniya, kuma a wannan babi, Zan koya muku game da yadda za a yi amfani da su a cikin gudanar da bincike. A Sashe 4.2, zan nuna ainihin dabaru na experimentation da wani misali na wani gwaji a kan Wikipedia. Sa'an nan kuma, a Sashe 4.3, Zan bayyana bambanci tsakanin Lab gwaje-gwajen da kuma filin gwaje-gwajen da bambance-bambance tsakanin analog gwaje-gwajen da digital gwaje-gwajen. Bugu da ari, zan bayar da hujjar cewa digital filin gwajen iya bayar da mafi kyau fasali na analog Lab gwaje-gwajen (m iko) da kuma analog filin gwajen (hakikanci), duk a sikelin cewa ba zai yiwu ba a baya. Next, a Sashe 4.4, Zan bayyana uku Concepts-tushe, heterogeneity magani effects, kuma sunadaran-da cewa su ne m for zayyana arziki gwaje-gwajen. Tare da cewa baya, Zan bayyana cinikayya-offs da hannu a cikin biyu main dabarun gudanar da gwaje-gwajen da digital: yin shi da kanka (Sashe 4.5.1) ko} awance da iko (Sashe 4.5.2). A karshe, zan gama da wasu zane shawara game da yadda za ka iya yi amfani da real ikon digital gwajen (Sashe 4.6.1) da kuma bayyana wasu daga alhakin da ya zo da cewa iko (Sashe 4.6.2). The babi za a gabatar da wani m ilmin lissafi tsarin rubutu da kuma m harshe. masu karatu da sha'awar a cikin wani more m, ilmin lissafi tsarin kula da gwaje-gwajen da ya kamata kuma karanta Technical Shafi a karshen sura.
