1. 載入套件與匯入資料

# 載入 haven 套件,用於讀取 SPSS 資料
library(haven)

# 載入 psych 套件,用於描述性統計分析
library(psych)

# 載入 car 套件,用於變異數同質性檢定
library(car)
## Loading required package: carData
## 
## Attaching package: 'car'
## The following object is masked from 'package:psych':
## 
##     logit
# 匯入 PISA 2022 資料
PISA <- read_sav("PISA_tawian2022_trimmed_lab.sav")

# 查看資料的基本摘要
summary(PISA)
##         CNT          CNTSTUID              NatCen         Gender     
##  Length   :5599   Min.   :15800002   Length   :5599   Min.   :1.000  
##  N.unique :   1   1st Qu.:15802092   N.unique :   1   1st Qu.:1.000  
##  N.blank  :   0   Median :15804235   N.blank  :   0   Median :2.000  
##  Min.nchar:   3   Mean   :15804221   Min.nchar:   6   Mean   :1.503  
##  Max.nchar:   3   3rd Qu.:15806338   Max.nchar:   6   3rd Qu.:2.000  
##                   Max.   :15808413                    Max.   :2.000  
##       AGE             ESCS             REPEAT             MISSSC       
##  Min.   :15.33   Min.   :-3.8421   Min.   :0.000000   Min.   :0.00000  
##  1st Qu.:15.58   1st Qu.:-0.9395   1st Qu.:0.000000   1st Qu.:0.00000  
##  Median :15.83   Median :-0.2368   Median :0.000000   Median :0.00000  
##  Mean   :15.81   Mean   :-0.2701   Mean   :0.007323   Mean   :0.02375  
##  3rd Qu.:16.08   3rd Qu.: 0.4393   3rd Qu.:0.000000   3rd Qu.:0.00000  
##  Max.   :16.33   Max.   : 4.2070   Max.   :1.000000   Max.   :1.00000  
##     SKIPPING      WORKPAY           MATHMOT           RELATST       
##  Min.   :0.0   Min.   : 0.0000   Min.   :0.00000   Min.   :-6.2677  
##  1st Qu.:0.0   1st Qu.: 0.0000   1st Qu.:0.00000   1st Qu.:-0.3331  
##  Median :0.0   Median : 0.0000   Median :0.00000   Median : 0.1440  
##  Mean   :0.1   Mean   : 0.6269   Mean   :0.04608   Mean   : 0.3006  
##  3rd Qu.:0.0   3rd Qu.: 0.0000   3rd Qu.:0.00000   3rd Qu.: 0.8408  
##  Max.   :1.0   Max.   :10.0000   Max.   :1.00000   Max.   : 3.1654  
##      BELONG            STRESAGR           GROSAGR           TEACHSUP      
##  Min.   :-3.25830   Min.   :-5.24990   Min.   :-3.5994   Min.   :-2.9095  
##  1st Qu.:-0.48610   1st Qu.:-0.39990   1st Qu.:-0.3061   1st Qu.:-0.3322  
##  Median :-0.24820   Median :-0.00690   Median :-0.0144   Median :-0.1002  
##  Mean   : 0.01419   Mean   :-0.04094   Mean   : 0.1384   Mean   : 0.2342  
##  3rd Qu.: 0.41630   3rd Qu.: 0.29860   3rd Qu.: 0.7798   3rd Qu.: 1.5558  
##  Max.   : 2.75620   Max.   : 5.58370   Max.   : 3.3724   Max.   : 1.5558  
##      ANXMAT           MATHPERS           PV1MATH         PV1READ     
##  Min.   :-2.3945   Min.   :-3.13190   Min.   :219.1   Min.   :167.4  
##  1st Qu.:-0.2758   1st Qu.:-1.08650   1st Qu.:460.4   1st Qu.:439.2  
##  Median : 0.3378   Median :-0.52750   Median :541.6   Median :515.9  
##  Mean   : 0.3078   Mean   :-0.51540   Mean   :537.8   Mean   :509.2  
##  3rd Qu.: 0.7889   3rd Qu.:-0.02115   3rd Qu.:618.8   3rd Qu.:582.0  
##  Max.   : 2.6350   Max.   : 2.83150   Max.   :917.4   Max.   :864.8  
##     PV1SCIE     
##  Min.   :194.7  
##  1st Qu.:462.5  
##  Median :536.1  
##  Mean   :530.8  
##  3rd Qu.:602.8  
##  Max.   :882.7

2. 描述性統計分析

# 計算全體學生數學成績的均值
mean(PISA$PV1MATH, na.rm = TRUE)
## [1] 537.822
# 計算全體學生數學成績的標準差
sd(PISA$PV1MATH, na.rm = TRUE)
## [1] 109.7305
# 依性別分組計算數學成績的描述性統計
# Gender:1 為女生,2 為男生
describeBy(PISA$PV1MATH, PISA$Gender)
## 
##  Descriptive statistics by group 
## group: 1
##    vars    n   mean     sd median trimmed    mad    min    max  range  skew
## X1    1 2780 535.84 102.26 538.56  536.99 108.38 227.79 821.56 593.77 -0.11
##    kurtosis   se
## X1     -0.4 1.94
## ------------------------------------------------------------ 
## group: 2
##    vars    n   mean     sd median trimmed    mad    min    max  range skew
## X1    1 2819 539.78 116.62 546.54  541.26 125.62 219.06 917.38 698.32 -0.1
##    kurtosis  se
## X1    -0.51 2.2
# 將性別轉換為類別變項
PISA$Gender <- as.factor(PISA$Gender)

# 查看不同性別的樣本數
summary(PISA$Gender)
##    1    2 
## 2780 2819

3. 變異數同質性檢定

# 使用 Levene 檢定判斷兩組母體變異數是否相等
# H0:兩組母體變異數相等
# H1:兩組母體變異數不相等
# center = "mean" 表示以平均數為中心

leveneTest(
  PISA$PV1MATH ~ PISA$Gender,
  center = "mean"
)
## Levene's Test for Homogeneity of Variance (center = "mean")
##         Df F value    Pr(>F)    
## group    1  59.342 1.557e-14 ***
##       5597                      
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Levene 檢定結果為 F(1, 5597) = 59.34, p < 0.001,達顯著水準,表示兩組具有變異數異質性。

4. 雙獨立樣本 t 檢定

# 因變異數異質,採用不合併變異數的 t 檢定
# var.equal = FALSE 表示不假設兩組變異數相等
# 採用調整後的自由度進行雙尾檢定

t.test(
  PISA$PV1MATH ~ PISA$Gender,
  var.equal = FALSE
)
## 
##  Welch Two Sample t-test
## 
## data:  PISA$PV1MATH by PISA$Gender
## t = -1.3461, df = 5521.6, p-value = 0.1783
## alternative hypothesis: true difference in means between group 1 and group 2 is not equal to 0
## 95 percent confidence interval:
##  -9.688443  1.799944
## sample estimates:
## mean in group 1 mean in group 2 
##        535.8361        539.7803

檢定結果為 t(5521.60) = -1.35, p = 0.18,未達顯著水準。

5. 結論

本研究以雙獨立樣本 t 檢定比較台灣男生與女生 在 PISA 2022 數學成績的均值差異。

由於 Levene 變異數同質性檢定達顯著水準, 因此採用不合併變異數的 t 檢定。

結果顯示 p = 0.18 > 0.05, 因此不拒絕虛無假設, 表示男生與女生的數學成績均值 未達統計上的顯著差異。