7 Imiqondo Yezibalo Wonke Usosayensi Wedatha Okufanele Afunde Ngayo (futhi Kungani)

Isithombe nguMbhali

# Isingeniso

Kulula ukubanjwa ohlangothini lobuchwepheshe lwesayensi yedatha njengokwenza eyakho iphumelele I-SQL futhi ama-panda amakhono, izinhlaka zokufunda zomshini, kanye nemitapo yolwazi efana I-Scikit-Learn. Lawo makhono abalulekile, kodwa akuthola kuze kube manje. Ngaphandle kokuqonda okuqinile kwezibalo ezingemuva komsebenzi wakho, kunzima ukusho ukuthi amamodeli akho athembekile nini, kunini lapho imininingwane yakho inengqondo, noma lapho idatha yakho ingahle ikudukise.

Ososayensi bedatha abahamba phambili ababona nje abahleli abanamakhono; futhi banokuqonda okuqinile kwedatha. Bayakwazi ukuhumusha ukungaqiniseki, ukubaluleka, ukuhlukahluka, nokuchema, okubasiza ukuthi bahlole ukuthi imiphumela ithembekile yini futhi benze izinqumo ezinolwazi.

Kulesi sihloko, sizohlola imiqondo eyisikhombisa yezibalo ewumongo ebonakala kaningi kusayensi yedatha – njengokuhlola kwe-A/B, ukumodela okubikezelwayo, kanye nokwenziwa kwezinqumo okuqhutshwa idatha. Sizoqala ngokubheka umehluko phakathi kokubaluleka kwezibalo nokusebenzayo.

# 1. Ukwehlukanisa Ukubaluleka Kwezibalo Nokubaluleka Okungokoqobo

Nansi into ojwayele ukuhlangana nayo: Usebenzisa ukuhlolwa kwe-A/B kuwebhusayithi yakho. Inguqulo B inezinga lokuguqulwa eliphezulu elingu-0.5% kunenguqulo A. Inani le-p lingu-0.03 (ngokwezibalo libalulekile!). Umphathi wakho uyabuza: “Ingabe kufanele sithumele inguqulo B?”

Impendulo ingase ikumangaze: mhlawumbe akunjalo. Ukuthi into ethile ibalulekile ngokwezibalo akusho ukuthi ibalulekile emhlabeni wangempela.

• Ukubaluleka kwezibalo kukutshela ukuthi umphumela ungokoqobo (hhayi ngenxa yenhlanhla)
• Ukubaluleka okungokoqobo kukutshela ukuthi lowo mphumela mkhulu ngokwanele yini ukuba ukhathalele

Ake sithi unezivakashi ezingu-10,000 eqenjini ngalinye. Inguqulo A iguqulela ku-5.0% futhi Inguqulo B iguqulela ku-5.05%. Lowo mehluko omncane ongu-0.05% ungabaluleka ngokwezibalo ngedatha eyanele. Kodwa nansi into: uma ukuguqulwa ngakunye kubiza u-$50 futhi uthola izivakashi zonyaka eziyisigidi esingu-1, lokhu kuthuthukiswa kukhiqiza kuphela u-$2,500 ngonyaka. Uma ukusebenzisa Inguqulo B kubiza $10,000, ayifaneleki naphezu kokuthi “ibalulekile ngokwezibalo.”

Bala njalo amasayizi omthelela kanye nomthelela webhizinisi ngokuhambisana namanani we-p. Ukubaluleka kwezibalo kukutshela ukuthi umphumela ungokoqobo. Ukubaluleka okusebenzayo kukutshela ukuthi kufanele yini ukhathalele.

# 2. Ukuqaphela Nokubhekana Nokuchema Kwesampula

Idathasethi yakho ayilokothi ilimele iqiniso eliphelele. Kuhlala kuyisampula, futhi uma leyo sampuli ingameleli, iziphetho zakho zizoba iphutha kungakhathaliseki ukuthi ukuhlaziya kwakho kuyinkimbinkimbi kangakanani.

Ukukhetha amasampula kwenzeka uma isampula lakho lihluka ngokwendlela inani labantu ozama ukuliqonda. Kungesinye sezizathu ezivame kakhulu zokuthi amamodeli ahluleke ekukhiqizeni.

Nasi isibonelo esicashile: zicabange uzama ukuqonda isilinganiso seminyaka yekhasimende lakho. Uthumela inhlolovo ku-inthanethi. Amakhasimende amancane kungenzeka aphendule izinhlolovo eziku-inthanethi. Imiphumela yakho ibonisa isilinganiso sobudala obungu-38, kodwa isilinganiso sangempela singu-45. Ulinganisele kancane ngeminyaka eyisikhombisa ngenxa yendlela oyiqoqe ngayo idatha.

Cabanga ngokuqeqesha imodeli yokuhlonza ukukhwabanisa emacaleni okukhwabanisa abikiwe. Kuzwakala kunengqondo, akunjalo? Kodwa ubona nje umkhonyovu osobala owabanjwa wabikwa. Ukukhwabanisa okuyinkimbinkimbi okungabonwanga akukho nhlobo kudatha yakho yokuqeqeshwa. Imodeli yakho ifunda ukubamba izinto ezilula kodwa igeje amaphethini ayingozi ngempela.

Indlela yokubamba ukuchema kwesampula: Qhathanisa isampula yakho yokusabalalisa nokusatshalaliswa kwabantu okwaziwayo uma kwenzeka. Buza ukuthi idatha yakho iqoqwe kanjani. Zibuze: “Ubani noma yini engekho kule dathasethi?”

# 3. Ukusebenzisa Izikhawu Zokuzethemba

Uma ubala imethrikhi kusuka kusampula – njengesilinganiso sezindleko zekhasimende noma izinga lokuguqulwa – uthola inombolo eyodwa. Kodwa leyo nombolo ayikutsheli ukuthi kufanele uqiniseke kangakanani.

Izikhathi zokuzithemba (CI) zikunikeza ububanzi lapho inani labantu bangempela okungenzeka lehla khona.

I-CI engu-95% isho ukuthi: uma siphinda le nqubo yesampula izikhathi eziyi-100, cishe ama-95 alezo zikhathi zingaqukatha ipharamitha yangempela yabantu.

Ake sithi ukala inani lempilo yekhasimende (CLV) kumakhasimende angu-20 futhi uthole isilinganiso esingu-$310. I-95% CI ingase ibe $290 kuya ku-$330. Lokhu kukutshela ukuthi isilinganiso sangempela se-CLV kuwo wonke amakhasimende cishe siwela kulolo bubanzi.

Nansi ingxenye ebalulekile: usayizi wesampula uthinta kakhulu i-CI. Ngamakhasimende angu-20, ungase ube $100 ibanga lokungaqiniseki. Ngamakhasimende angu-500, lobo bubanzi buncipha ukuze bufinyelele ku-$30. Ukulinganisa okufanayo kuba nokunemba kakhulu.

Esikhundleni sokubika “isilinganiso se-CLV sithi $310,” kufanele ubike “isilinganiso se-CLV ngu-$310 (95% CI: $290-$330).” Lokhu kuthinta kokubili isilinganiso sakho nokungaqiniseki kwakho. Izikhawu zokuzethemba ezibanzi ziyisignali yokuthi udinga idatha eyengeziwe ngaphambi kokwenza izinqumo ezinkulu. Ekuhlolweni kwe-A/B, uma i-CI igqagqana kakhulu, okuhlukile kungenzeka empeleni kungahluka nhlobo. Lokhu kuvimbela iziphetho zokuzethemba ngokweqile kumasampuli amancane futhi kugcina izincomo zakho zisekelwe eqinisweni.

# 4. Ukuhumusha Amagugu Ka-P Ngokufanelekile

Ama-P-values ​​cishe angumqondo ongaqondwa kahle kakhulu kwizibalo. Nakhu okushiwo inani le-p empeleni: Uma i-null hypothesis ibiyiqiniso, amathuba okubona imiphumela okungenani ngokwedlulele njengalokho esikubonile.

Nakhu AKUSHO:

• Amathuba okuthi i-null hypothesis iyiqiniso
• Amathuba okuthi imiphumela yakho ingenxa yenhlanhla
• Ukubaluleka kokuthola kwakho
• Amathuba okwenza iphutha

Ake sisebenzise isibonelo esiphathekayo. Uyahlola uma isici esisha sikhulisa ukuzibandakanya komsebenzisi. Ngokomlando, abasebenzisi bachitha isilinganiso semizuzu engu-15 iseshini ngayinye. Ngemva kokwethula isici kubasebenzisi abangu-30, benza isilinganiso semizuzu engu-18.5. Ubala inani lika-p elingu-0.02.

• Ukuhumusha okungalungile: “Kunamathuba angu-2% okuthi isici singasebenzi.”
• Ukuhumusha okulungile: “Uma isici singenawo umthelela, besizobona imiphumela ngale ndlela eyeqisayo kuphela engu-2% wesikhathi. Njengoba lokho kungenzeki, siphetha ngokuthi isici cishe sinomphumela.”

Umehluko ucashile kodwa ubalulekile. I-p-value ayikutsheli ukuthi i-hypothesis yakho iyiqiniso. Ikutshela ukuthi idatha yakho ingamangaza kanjani ukube ubungekho umthelela wangempela.

Gwema ukubika kuphela amanani we-p ngaphandle kosayizi bomphumela. Bika kokubili njalo. Umthelela omncane, ongasho lutho ungaba nenani elincane lika-p elinedatha eyanele. Umthelela omkhulu, obalulekile ungaba nenani elikhulu le-p elinedatha encane kakhulu. I-p-value iyodwa ayikutsheli lokho okudingeka ukwazi.

# 5. Ukuqonda Amaphutha Ohlobo I kanye Nohlobo II

Ngaso sonke isikhathi uma wenza uhlolo lwezibalo, ungenza izinhlobo ezimbili zamaphutha:

• Iphutha Lohlobo I (Okuhle Okungelona iqiniso): Ukuphetha kukhona umphumela uma ungekho. Uvula isici esingasebenzi ngempela.
• Iphutha Lohlobo II (Alukho Ngamanga): Akukho mphumela wangempela. Awuqalisi isici ebesingasiza.

Lawa maphutha ahwebelana ngawodwa. Nciphisa eyodwa, futhi uvame ukwandisa enye.

Cabanga ngokuhlolwa kwezokwelapha. Iphutha loHlobo I lisho ukuxilongwa okungelona iqiniso: othile uthola ukwelashwa nokukhathazeka okungadingekile. Iphutha loHlobo lwe-II lisho ukushoda kwesifo lapho sikhona ngempela: akukho ukwelashwa lapho sidingeka.

Ekuhlolweni kwe-A/B, iphutha lohlobo I lisho ukuthi uthumela isici esingenamsebenzi futhi umosha isikhathi sobunjiniyela. Iphutha Lohlobo II lisho ukuthi ugeje isici esihle futhi ulahlekelwe yithuba.

Nakhu abantu abaningi abangakuqapheli: usayizi wesampula usiza ukugwema amaphutha ohlobo II. Ngamasampuli amancane, ngokuvamile uzolahlekelwa imiphumela yangempela ngisho nalapho ikhona. Ithi uhlola isici esinyusa ukuguqulwa kusuka ku-10% kuya ku-12% — ukuphakamisa okuphelele okungu-2%. Ngabasebenzisi abayi-100 kuphela eqenjini ngalinye, ungathola lo mphumela kuphela u-20% wesikhathi. Uzophuthelwa isikhathi esingu-80% yize kuyiqiniso. Ngabasebenzisi abangu-1,000 iqembu ngalinye, uzolithola u-80% wesikhathi.

Kungakho ukubala usayizi wesampula odingekayo ngaphambi kokwenza izivivinyo kubaluleke kakhulu. Udinga ukwazi ukuthi uzokwazi yini ukubona imiphumela ebalulekile.

# 6. Ukwehlukanisa Ukuhlobana kanye Nembangela

Lona umgodi wezibalo odume kakhulu, nokho abantu basawela kuwo njalo.

Ukuthi izinto ezimbili ziyahamba ndawonye akusho ukuthi eyodwa idala enye. Nasi isibonelo sesayensi yedatha. Uyaqaphela ukuthi abasebenzisi abazibandakanya kakhulu nohlelo lwakho lokusebenza banemali engenayo ephezulu. Ingabe ukusebenzelana kubangela imali? Kungenzeka. Kodwa futhi kuyenzeka ukuthi abasebenzisi abathola inani eliningi kumkhiqizo wakho (isizathu sangempela) bobabili bahlanganyele okwengeziwe FUTHI bachithe ngaphezulu. Inani lomkhiqizo liyindida edala ukuhlobana.

Abasebenzisi abafunda kabanzi bavame ukuthola amaphuzu angcono okuhlolwa. Ingabe isikhathi sokufunda sidala amaphuzu angcono? Ngokwengxenye, yebo. Kepha abafundi abanolwazi lwangaphambilini kanye nogqozi oluphakeme bobabili bafunda kakhulu futhi benze kangcono. Ulwazi lwangaphambili kanye nogqozi kuyindida.

Izinkampani ezinabasebenzi abaningi zivame ukuba nemali ephezulu. Ingabe abasebenzi bayayidala imali? Hhayi ngokuqondile. Ubukhulu benkampani kanye nesigaba sokukhula kuqhuba ukuqashwa kanye nokukhuphuka kwemali engenayo.

Nawa amafulegi ambalwa abomvu okuxhumana okungamanga:

• Ukuxhumana okuphezulu kakhulu (ngaphezulu kuka-0.9) ngaphandle kwendlela esobala
• Okuhlukile kwesithathu kungathinta ngokusobala kokubili
• Uchungechunge lwesikhathi oluvele luthambekele kokubili phezulu ngokuhamba kwesikhathi

Ukusungula imbangela yangempela kunzima. Izinga legolide ukuhlola okungahleliwe (ukuhlolwa kwe-A/B) lapho isabelo esingahleliwe sishayisana khona. Ungakwazi futhi ukusebenzisa izivivinyo zemvelo uma uthola izimo lapho umsebenzi ozokwenziwa “njengokungathi” okungahleliwe. Izindlela ze-causal inference ezifana nezinsimbi eziguquguqukayo kanye nomehluko-ngomehluko zisiza ngedatha yokuqaphela. Futhi ulwazi lwesizinda lubalulekile.

# 7. Ukuzulazula kusiqalekiso sobukhulu

Abaqalayo bavame ukucabanga: “Izici ezengeziwe = imodeli engcono.” Ososayensi bedatha abanolwazi bayazi ukuthi lokhu akulungile.

Njengoba wengeza ubukhulu (izici), kwenzeka izinto ezimbi ezimbalwa:

• Idatha iba yincane kakhulu
• Amamethrikhi ebanga aba nencazelo encane
• Udinga idatha eyengeziwe ngokukhula
• Amamodeli adlula kalula kalula

Nansi intuition. Cabanga ukuthi unamaphuzu edatha ayi-1,000. Kubukhulu obubodwa (umugqa), lawo maphuzu aminyene kakhulu. Ngezilinganiso ezimbili (indiza), zisabalele kakhulu. Ngobukhulu obuthathu (i-cube), isakazwe nangokwengeziwe. Uma ufinyelela ubukhulu obuyi-100, lawo maphuzu angu-1,000 asuke ayingcosana ngendlela emangalisayo. Wonke amaphuzu akude nawo wonke amanye amaphuzu. Umqondo othi “umakhelwane oseduze” ucishe ube yize. Ayisekho into ethi “eduze” manje.

Umphumela ophikisayo: Ukwengeza izici ezingabalulekile kulimaza ukusebenza, ngisho nenani elifanayo ledatha. Yingakho ukukhethwa kwesici kubalulekile. Kumele:

# Esonga

Le mibono eyisikhombisa yenza isisekelo sokucabanga kwezibalo kusayensi yedatha. Kusayensi yedatha, amathuluzi nezinhlaka zizohlala zivela. Kodwa ikhono lokucabanga ngokwezibalo – ukubuza, ukuhlola, nokubonisana ngedatha – liyohlala liyikhono elihlukanisa ososayensi bedatha abakhulu.

Ngakho-ke ngesikhathi esilandelayo lapho uhlaziya idatha, wakha imodeli, noma wethula imiphumela, zibuze:

• Ingabe lo mphumela mkhulu ngokwanele ukuba ube nendaba, noma uyabonakala ngokwezibalo?
• Ingabe isampula lami lingachema ngezindlela engingazange ngizicabange?
• Lithini ibanga lami lokungaqiniseki, hhayi nje isilinganiso sephuzu lami?
• Ingabe ngidida ukubaluleka kwezibalo neqiniso?
• Yimaphi amaphutha engingase ngiwenze, futhi yiliphi elibaluleke kakhulu?
• Ingabe ngibona ukuhlobana noma imbangela yangempela?
• Ingabe nginezici eziningi kakhulu ezihlobene nedatha yami?

Le mibuzo izokuqondisa eziphethweni ezinokwethenjelwa nezinqumo ezingcono. Njengoba wakha umsebenzi wakho kusayensi yedatha, thatha isikhathi sokuqinisa isisekelo sakho sezibalo. Akulona ikhono elikhazimulayo, kodwa yilona elizokwenza umsebenzi wakho uthembeke ngempela. Ukufunda okujabulisayo!

Bala Priya C ungunjiniyela kanye nombhali wezobuchwepheshe ovela eNdiya. Uthanda ukusebenza ezimpambanweni zezibalo, izinhlelo, isayensi yedatha, nokudalwa kokuqukethwe. Izindawo zakhe azithandayo nobungcweti zifaka i-DevOps, isayensi yedatha, nokucubungula ulimi lwemvelo. Uyakujabulela ukufunda, ukubhala, ukubhala amakhodi, kanye nekhofi! Okwamanje, usebenzela ukufunda nokwabelana ngolwazi lwakhe nomphakathi wonjiniyela ngokugunyaza izifundo, imihlahlandlela yokuthi kwenziwa kanjani, imibono, nokuningi. I-Bala iphinda idale ukubuka konke kwensiza okubandakanyayo kanye nokufundisa ngekhodi.