两个群体的比较-Stata教学省名师优质课赛课获奖课件市赛课百校联赛优质课一等奖课件

Stata教學第四講兩個樣本之間比較1/63©Ming-chiChen1社會統計打開85q1family.dta這個社會變遷基本資料調查第三期第二次家庭Stata資料檔因為汉字相容性問題有一些亂碼，辨識不易能够打開85q1_format.txt看變數名稱以及變數值名稱以j2、j3為例j2問受訪者「拾.2.通常您平均每週大約花多少時間做家務工作？_______小時」j3問受訪者「拾.3.通常您配偶平均每週大約花多少時間做家務工作？_______小時」2/63©Ming-chiChen2社會統計我們資料裡有變數標籤，不过因為相容性關係會有亂碼查看是否有亂碼？Data-dataeditor在j2這個變數名稱上click一下，下面一整欄數值都反白了滑鼠右鍵-variable-properties-label出現汉字是「通常您平均牢週大約花多少時間做家務工作︺」把亂碼改好也將j3變數標籤亂碼改好3/63©Ming-chiChen3社會統計查看變數有無異常值關掉Dataeditor視窗用boxplot來看有無極端值Graphics-easygraphs-boxplot-main-在variable空格裡鍵入j24/63©Ming-chiChen4社會統計用boxplot來看有無極端值5/63©Ming-chiChen5社會統計同樣方法也能够查看j3極端值也能够直接在指令欄6/63©Ming-chiChen6社會統計這就是指令欄7/63©Ming-chiChen7社會統計在指令欄裡直接鍵入Graphboxj2然後按enter8/63©Ming-chiChen8社會統計Summarizevarname,detail

指令欄鍵入summarizej2,detail或statistics-summaries,tables,&tests-summarystatistics-summarystatistics9/63©Ming-chiChen9社會統計.通常您平均每週大約花多少時間做家務工作？-------------------------------------------------------------PercentilesSmallest1%005%0010%00Obs192425%20SumofWgt.192450%7Mean50.32692LargestStd.Dev.191.134275%2099890%35998Variance36532.2895%70998Skewness4.71770799%996999Kurtosis23.40378太愛做家事了吧！高得不合理10/63©Ming-chiChen10社會統計Recode極端值我們到85q1_format.txt去看，發現J2J3996"不知道"998"不適用"999"拒答"所以要把995以上定義為systemmissingRecodej2995/max=.這裡句點.就是Stata系統定義缺失值。11/63©Ming-chiChen11社會統計.summarizej2,detail通常您平均每週大約花多少時間做家務工作？-------------------------------------------------------------PercentilesSmallest1%005%0010%00Obs184925%20SumofWgt.184950%7Mean11.96106LargestStd.Dev.15.3076275%1510590%28112Variance234.323295%36168Skewness3.20855599%70168Kurtosis20.90302一週只有168小時，所以應該合理換算，以一天16小時算，一週112小時12/6312.inspectj2j2:通常您平均每週大約花多少時間做家務工作NumberofObservations-------------------------------------------------------------------------TotalIntegersNonintegers|#Negative---|#Zero305305-|#Positive15441544-|#---------------|#Total18491849-|#....Missing75+---------------------------01681924(47uniquevalues)用inspect來看大致分佈以及缺失個案數Data-describedata-inspectvariables13/6313Recodej2168=11214/63©Ming-chiChen14社會統計.inspectj2j2:通常您平均每週大約花多少時間做家務工作NumberofObservations-------------------------------------------------------------------------TotalIntegersNonintegers|#Negative---|#Zero305305-|#Positive15441544-|#---------------|#Total18491849-|#....Missing75+---------------------------01121924(46uniquevalues)15/6315.sumj2,detail通常您平均每週大約花多少時間做家務工作？-------------------------------------------------------------PercentilesSmallest1%005%0010%00Obs184925%20SumofWgt.184950%7Mean11.90049LargestStd.Dev.14.7918875%1510590%28112Variance218.799695%36112Skewness2.63237799%70112Kurtosis12.8735916/6316.inspectj3j3:通常您配偶平均每週大約花多少時間做家NumberofObservations-------------------------------------------------------------------------TotalIntegersNonintegers|#Negative---|#Zero263263-|#Positive16611661-|#---------------|##Total19241924-|#...#Missing-+---------------------------09991924(54uniquevalues)17/6317.summarizej3,detail通常您配偶平均每週大約花多少時間做家務工作？PercentilesSmallest1%005%0010%00Obs192425%40SumofWgt.192450%14Mean278.8342LargestStd.Dev.436.233675%99699890%998999Variance190299.795%998999Skewness1.0388899%998999Kurtosis2.08566618/6318Missingvalue&recodeRecodej3990/max=.Recodej3168=11219/63©Ming-chiChen19社會統計.recodej3168=112(j3:4changesmade).inspectj3j3:通常您配偶平均每週大約花多少時間做家NumberofObservations-------------------------------------------------------------------------TotalIntegersNonintegers|#Negative---|#Zero263263-|#Positive11441144-|#---------------|#Total14071407-|#....Missing517+---------------------------01501924(50uniquevalues)20/6320.summarizej3,detail通常您配偶平均每週大約花多少時間做家務工作？PercentilesSmallest1%005%0010%00Obs140725%20SumofWgt.140750%7Mean14.49893LargestStd.Dev.18.229675%2111290%35112Variance332.318595%49150Skewness2.56952699%85150Kurtosis12.6505921/6321Recodej3112/max=112Tabulatej322/63©Ming-chiChen22社會統計70|100.7198.2980|30.2198.5184|60.4398.9385|10.0799.0090|10.0799.0898|40.2899.36100|10.0799.43105|10.0799.50112|70.50100.00------------+-----------------------------------Total|1,407100.0023/63©Ming-chiChen23社會統計來看看男女差別A1.這題是性別，男是1，女是2。Data-dataeditor-找A1這個變數-滑鼠右鍵Variable-properties-label改成性別Valuelabel-define/modify-define-labelname輸入gender-OK-value鍵入1-text鍵入男-OKvalue鍵入1-text鍵入男-OK-cancel-close-valuelabel選擇gender-OK關掉Dataeditor視窗24/63©Ming-chiChen24社會統計男女家務分擔是否有不一样？Statistics-Summaries,tables,&tests-tables-One/Two-waytableofsummarystatistics自變數依變數25/63©Ming-chiChen25社會統計差別很大嗎？|Summaryof|通常您平均每週大約花多少時間做家務工作|性別|MeanStd.Dev.Freq.------------+------------------------------------男|6.048553710.23684968女|18.33030616.287017881------------+------------------------------------Total|11.90048714.791877184926/63©Ming-chiChen26社會統計母體變異數未知但已知相等Statistics-Summaries,tables,&tests-Classicaltestsofhypotheses-Groupmeancomparisontests依變數自變數信賴水準27/63©Ming-chiChen27社會統計.ttestj2,by(a1)level(99)Two-samplettestwithequalvariances------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|9686.048554.329024510.236845.1993676.897741女|88118.33031.548723516.2870216.9138219.7468---------+--------------------------------------------------------------------combined|184911.90049.343997114.7918811.0134912.78748---------+--------------------------------------------------------------------diff|-12.28175.6268771-13.89815-10.66535------------------------------------------------------------------------------diff=mean(男)-mean(女)t=-19.5920Ho:diff=0degreesoffreedom=1847Ha:diff<0Ha:diff!=0Ha:diff>0Pr(T<t)=0.0000Pr(|T|>|t|)=0.0000Pr(T>t)=1.000028/6328母體變異數未知但已知不相等以上方法是假設母體變異數未知但已知相等。不论樣本大小，統計軟體普通用t檢定那假如母體變異數未知但已知不相等，怎麼辦？29/63©Ming-chiChen29社會統計母體變異數未知但已知不相等Statistics-Summaries,tables,&tests-Classicaltestsofhypotheses-Groupmeancomparisontests變異數不相等自由度需要比較複雜，由Welch提出運算方式30/63©Ming-chiChen30社會統計男女性負擔家務工作時數差異，在母體變異數未知但已知不等情況下.ttestj2,by(a1)unequalwelchlevel(99)Two-samplettestwithunequalvariances------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|9686.048554.329024510.236845.1993676.897741女|88118.33031.548723516.2870216.9138219.7468---------+--------------------------------------------------------------------combined|184911.90049.343997114.7918811.0134912.78748---------+--------------------------------------------------------------------diff|-12.28175.6398083-13.93195-10.63155------------------------------------------------------------------------------diff=mean(男)-mean(女)t=-19.1960Ho:diff=0Welch'sdegreesoffreedom=1456.62Ha:diff<0Ha:diff!=0Ha:diff>0Pr(T<t)=0.0000Pr(|T|>|t|)=0.0000Pr(T>t)=1.000031/63©Ming-chiChen31社會統計變異數相等與否Levene檢定Statistics-Summaries,tables,&tests-Classicaltestsofhypotheses-Groupvariancecomparisontests依變數自變數32/63©Ming-chiChen32社會統計變異數相等與否Levene檢定.sdtestj2,by(a1)level(99)Varianceratiotest------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|9686.048554.329024510.236845.1993676.897741女|88118.33031.548723516.2870216.9138219.7468---------+--------------------------------------------------------------------combined|184911.90049.343997114.7918811.0134912.78748------------------------------------------------------------------------------ratio=sd(男)/sd(女)f=0.3950Ho:ratio=1degreesoffreedom=967,880Ha:ratio<1Ha:ratio!=1Ha:ratio>1Pr(F<f)=0.00002*Pr(F<f)=0.0000Pr(F>f)=1.0000sd(男)/sd(女)不等於一，p值顯示能够拒斥變異數相等虛無假設33/63©Ming-chiChen33社會統計根據Levene檢定結果，選擇變異數不相等假設比較正確。也就是男性分擔家務時數顯著地少於女性。34/63©Ming-chiChen34社會統計已婚未婚者家務工作負擔比較A5為受訪者婚姻狀況1為未婚，2為已婚，3為其它已婚者家務負擔比較大嗎？35/63©Ming-chiChen35社會統計已婚未婚者家務工作負擔比較仿照男女比較得到以下錯誤回報.ttestj2,by(a5)level(99)morethan2groupsfound,only2allowedr(420);這是因為a5這個變數有三個變數值：未婚、已婚和其它要用條件是來限制，僅比較未婚者和已婚者36/63©Ming-chiChen36社會統計Statistics-Summaries,tables,&tests-Classicaltestsofhypotheses-Groupmeancomparisontests37/63©Ming-chiChen37社會統計變異數相等.ttestj2ifa5!=3,by(a5)level(99)Two-samplettestwithequalvariances------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------未婚|3065.598039.51562499.0197524.2615166.934562已婚|153113.12671.391287315.3102912.1175714.13586---------+--------------------------------------------------------------------combined|183711.87262.343479314.721610.9869512.75828---------+--------------------------------------------------------------------diff|-7.528675.9051995-9.862742-5.194608------------------------------------------------------------------------------diff=mean(未婚)-mean(已婚)t=-8.3171Ho:diff=0degreesoffreedom=1835Ha:diff<0Ha:diff!=0Ha:diff>0Pr(T<t)=0.0000Pr(|T|>|t|)=0.0000Pr(T>t)=1.000038/63©Ming-chiChen38社會統計變異數不相等.ttestj2ifa5!=3,by(a5)unequalwelchlevel(99)Two-samplettestwithunequalvariances------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------未婚|3065.598039.51562499.0197524.2615166.934562已婚|153113.12671.391287315.3102912.1175714.13586---------+--------------------------------------------------------------------combined|183711.87262.343479314.721610.9869512.75828---------+--------------------------------------------------------------------diff|-7.528675.6472826-9.4-5.85691------------------------------------------------------------------------------diff=mean(未婚)-mean(已婚)t=-11.6312Ho:diff=0Welch'sdegreesoffreedom=712.885Ha:diff<0Ha:diff!=0Ha:diff>0Pr(T<t)=0.0000Pr(|T|>|t|)=0.0000Pr(T>t)=1.000039/63©Ming-chiChen39社會統計Levene檢定.sdtestj2ifa5!=3,by(a5)level(99)Varianceratiotest------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------未婚|3065.598039.51562499.0197524.2615166.934562已婚|153113.12671.391287315.3102912.1175714.13586---------+--------------------------------------------------------------------combined|183711.87262.343479314.721610.9869512.75828------------------------------------------------------------------------------ratio=sd(未婚)/sd(已婚)f=0.3471Ho:ratio=1degreesoffreedom=305,1530Ha:ratio<1Ha:ratio!=1Ha:ratio>1Pr(F<f)=0.00002*Pr(F<f)=0.0000Pr(F>f)=1.0000無法拒斥變異數相等虛無假設40/63©Ming-chiChen40社會統計兩層群體比較已婚男女間，未婚男女間是否有差異？婚姻是否不利於女性（最少就花在家務勞動上時間而言）？41/63©Ming-chiChen41社會統計變異數相等Statistics-Summaries,tables,&tests-Classicaltestsofhypotheses-Groupmeancomparisontests42/63©Ming-chiChen42社會統計.bya5,sort:ttestj2ifa5!=3,by(a1)level(99)-------------------------------------------------------------------------------------------->a5=未婚Two-samplettestwithequalvariances------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|1775.316384.799297510.633963.2349727.397796女|1295.984496.54352526.1732594.5632957.405698---------+--------------------------------------------------------------------combined|3065.598039.51562499.0197524.2615166.934562---------+--------------------------------------------------------------------diff|-.66811191.04519-3.3773472.041123------------------------------------------------------------------------------diff=mean(男)-mean(女)t=-0.6392Ho:diff=0degreesoffreedom=304Ha:diff<0Ha:diff!=0Ha:diff>0Pr(T<t)=0.2616Pr(|T|>|t|)=0.5232Pr(T>t)=0.7384多重比較變異數相等43/6343多重比較變異數相等->a5=已婚Two-samplettestwithequalvariances------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|7846.095663.34930239.7804655.1937226.997605女|74720.50602.605493516.5489318.9423822.06967---------+--------------------------------------------------------------------combined|153113.12671.391287315.3102912.1175714.13586---------+--------------------------------------------------------------------diff|-14.41036.6909184-16.19227-12.62845------------------------------------------------------------------------------diff=mean(男)-mean(女)t=-20.8568Ho:diff=0degreesoffreedom=1529Ha:diff<0Ha:diff!=0Ha:diff>0Pr(T<t)=0.0000Pr(|T|>|t|)=0.0000Pr(T>t)=1.000044/6344多重比較變異數不相等.bya5,sort:ttestj2ifa5!=3,by(a1)unequalwelchlevel(99)-------------------------------------------------------------------------------------------->a5=未婚Two-samplettestwithunequalvariances------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|1775.316384.799297510.633963.2349727.397796女|1295.984496.54352526.1732594.5632957.405698---------+--------------------------------------------------------------------combined|3065.598039.51562499.0197524.2615166.934562---------+--------------------------------------------------------------------diff|-.6681119.96659-3.1742321.838008------------------------------------------------------------------------------diff=mean(男)-mean(女)t=-0.6912Ho:diff=0Welch'sdegreesoffreedom=292.466Ha:diff<0Ha:diff!=0Ha:diff>0Pr(T<t)=0.2450Pr(|T|>|t|)=0.4900Pr(T>t)=0.755045/6345多重比較變異數不相等->a5=已婚Two-samplettestwithunequalvariances------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|7846.095663.34930239.7804655.1937226.997605女|74720.50602.605493516.5489318.9423822.06967---------+--------------------------------------------------------------------combined|153113.12671.391287315.3102912.1175714.13586---------+--------------------------------------------------------------------diff|-14.41036.699024-16.2138-12.60693------------------------------------------------------------------------------diff=mean(男)-mean(女)t=-20.6150Ho:diff=0Welch'sdegreesoffreedom=1199.87Ha:diff<0Ha:diff!=0Ha:diff>0Pr(T<t)=0.0000Pr(|T|>|t|)=0.0000Pr(T>t)=1.000046/6346多層次比較變異數相等檢定.bya5,sort:sdtestj2ifa5!=3,by(a1)level(99)-------------------------------------------------------------------------------------------->a5=未婚Varianceratiotest------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|1775.316384.799297510.633963.2349727.397796女|1295.984496.54352526.1732594.5632957.405698---------+--------------------------------------------------------------------combined|3065.598039.51562499.0197524.2615166.934562------------------------------------------------------------------------------ratio=sd(男)/sd(女)f=2.9673Ho:ratio=1degreesoffreedom=176,128Ha:ratio<1Ha:ratio!=1Ha:ratio>1Pr(F<f)=1.00002*Pr(F>f)=0.0000Pr(F>f)=0.000047/6347多層次比較變異數相等檢定->a5=已婚Varianceratiotest------------------------------------------------------------------------------Group|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------男|7846.095663.34930239.7804655.1937226.997605女|74720.50602.605493516.5489318.9423822.06967---------+--------------------------------------------------------------------combined|153113.12671.391287315.3102912.1175714.13586------------------------------------------------------------------------------ratio=sd(男)/sd(女)f=0.3493Ho:ratio=1degreesoffreedom=783,746Ha:ratio<1Ha:ratio!=1Ha:ratio>1Pr(F<f)=0.00002*Pr(F<f)=0.0000Pr(F>f)=1.000048/6348BoxPlot箱型圖比較49/63©Ming-chiChen49社會統計單身男性和已婚男性是否有差別？單身女性和已婚女性是否有差別？50/63©Ming-chiChen50社會統計配對樣本結婚對女性不利？前例分析中，我們比較已婚者與未婚者從事家務時間差異，由此來推論婚前婚後可能產生變化。但「婚前組」與「婚後組」是由不一样受訪者所構成獨立樣本。假如「是否結婚」與一些人格特質有關，則我們不知道是因為「婚姻」本身造成行為上改變，還是含有某種行為傾向人比較轻易選擇婚姻。即我們分析可能隱藏「自我選擇」self-selection問題51/63©Ming-chiChen51社會統計配對樣本為了證明婚姻對從事家務時間影響不是來自於自我選擇，更加好分析樣本為長期追蹤資料（longitudinaldata），即能追蹤同一個受訪者，在婚前及婚後所產生行為上變化。但這種樣本資料蒐集十分費時費力。52/63©Ming-chiChen52社會統計配對樣本夫妻之間從事家務時間是否有顯著差異？我們能够用兩種方式來分析：將已婚男性與已婚女性當作兩獨立樣本，比較全部先生平均值與太太平均值是否有差異？53/63©Ming-chiChen53社會統計配對樣本但夫妻從事家務時間不是「獨立事件」，先生多分擔，太太自然能够少做。所以應該比較同一家庭中，夫與妻從事家務時間是否有差異，而不是比較全部「夫」平均值與全部「妻」平均值。54/63©Ming-chiChen54社會統計Statistics-Summaries,tables,&tests-Classicaltestsofhypotheses-Meancomparisontests,paireddata1st-2nd55/63©Ming-chiChen55社會統計夫妻之間家務分工Pairedttest------------------------------------------------------------------------------Variable|ObsMeanStd.Err.Std.Dev.[99%Conf.Interval]---------+--------------------------------------------------------------------j2|138012.80652.397152414.7535611.7821113.83094j3|138014.32391.476299917.6937613.0953515.55248---------+--------------------------------------------------------------------diff|1380-1.517391.657830424.43732-3.214199.1794161------------------------------------------------------------------------------mean(diff)=mean(j2-j3)