Look at the original dataset

##   student_id plan_id                 name Grade Weekly_Assessments_Given
## 1          1     584 T1 Rational Counting    PK                        0
## 2          1     589             T1 Rhyme    PK                        1
## 3          1    1097    T1 Quantification    PK                        0
## 4          1    1173         T1 Syllables    PK                        0
## 5          1    1696    T1 Number Symbols    PK                        0
## 6          1    1908          T1 Phonemes    PK                        3
##   Number.of.Exit.Exam preclass_exit_exam first_exit_exam second_exit_exam
## 1                   1                 NA              80               NA
## 2                   1                 NA             100               NA
## 3                   1                 NA              NA              100
## 4                   1                 NA             100               NA
## 5                   1                 NA              NA               30
## 6                   2                 NA             100              100
##   third_exit_exam Maximum_Exit_Score Pass_Exam_or_Not
## 1              NA                 80             Pass
## 2              NA                100             Pass
## 3              NA                100             Pass
## 4              NA                100             Pass
## 5              NA                 30             Fail
## 6              NA                100             Pass

Build logistic regression model to check the effect of the number of exit exam on passing exit exam

## 
## Call:
## glm(formula = factor(Pass) ~ factor(Grade) + factor(NumExit), 
##     family = binomial(link = "logit"), data = exit2)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -1.8978   0.6009   0.6009   0.7221   0.8667  
## 
## Coefficients:
##                   Estimate Std. Error z value Pr(>|z|)    
## (Intercept)        1.62029    0.05424  29.872  < 2e-16 ***
## factor(Grade)PS   -0.40908    0.06724  -6.084 1.17e-09 ***
## factor(NumExit)2  -0.01716    0.08234  -0.208   0.8349    
## factor(NumExit)3  -0.37083    0.21605  -1.716   0.0861 .  
## factor(NumExit)4  -0.42556    0.53536  -0.795   0.4267    
## factor(NumExit)5  10.94577  187.49087   0.058   0.9534    
## factor(NumExit)6 -14.18635  324.74370  -0.044   0.9652    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 5706.9  on 5698  degrees of freedom
## Residual deviance: 5661.7  on 5692  degrees of freedom
## AIC: 5675.7
## 
## Number of Fisher Scoring iterations: 11

In this result, Grade has a great impact on passing exit exam, and the number of exit exam also has a great impact on students’ exit exam performance.In this case, I don’t consider the effect of plans. Next, we will only consider several frequently used plan to investigate the relationship between the number of exit exams and student’s overall performance in exit exam(s)

Summarize how many groups in plans

##              T1 Addition Strategies           T1 Classification/Sorting 
##                                 159                                  19 
##                T1 Comparative Value                   T1 Compound Words 
##                                  85                                 256 
##                    T1 Conversations         T1 Expression: Ask & Answer 
##                                  36                                  73 
## T1 Expression: Descriptive Language                     T1 Final Sounds 
##                                 293                                   2 
##                   T1 Initial Sounds                   T1 Number Symbols 
##                                  30                                 423 
##                       T1 One-to-One               T1 Oral Comprehension 
##                                 324                                 200 
##                         T1 Ordering                         T1 Patterns 
##                                   9                                  10 
##                         T1 Phonemes                   T1 Quantification 
##                                 268                                 567 
##                T1 Rational Counting                            T1 Rhyme 
##                                 929                                 786 
##                    T1 Rote Counting                T1 Shape Composition 
##                                 255                                  12 
##             T1 Shape Identification                T1 Spatial Awareness 
##                                  27                                  14 
##           T1 Subtraction Strategies                        T1 Syllables 
##                                  37                                 336 
##                   T1 Word Awareness                    T2 Rote Counting 
##                                 534                                  13 
##                   T2 Word Awareness 
##                                   2
##  PK  PS 
## 696 767

Build logistic regression model for the following plans alone: T1 rhyme, T1 word awareness, T1 rote counting, and T1 one-to-one (those are the frequently used plans)

##    1    2    3    4    6 
## 1060  358   32   12    1
## 
## Call:
## glm(formula = factor(Pass) ~ factor(Grade) + factor(NumExit), 
##     family = binomial(link = "logit"), data = data1)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -2.0440  -1.2574   0.6646   0.8746   1.0995  
## 
## Coefficients:
##                  Estimate Std. Error z value Pr(>|z|)    
## (Intercept)        1.3978     0.1040  13.445  < 2e-16 ***
## factor(Grade)PS   -0.6339     0.1250  -5.073 3.92e-07 ***
## factor(NumExit)2   0.2072     0.1466   1.413    0.158    
## factor(NumExit)3   0.5590     0.4955   1.128    0.259    
## factor(NumExit)4  -0.5779     0.5951  -0.971    0.331    
## factor(NumExit)6 -13.9639   324.7437  -0.043    0.966    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 1650.3  on 1462  degrees of freedom
## Residual deviance: 1615.3  on 1457  degrees of freedom
## AIC: 1627.3
## 
## Number of Fisher Scoring iterations: 11

Only grade signficant affects students’ performance of passing exit exam. However,the Number of Exit exams doesn’t

The effect of weekly Assessment given on passing exit exam

model2 <- glm(factor(Pass) ~ factor(Weekly_Assessments_Given),family=binomial(link='logit'),data=data1)
summary(model2)
## 
## Call:
## glm(formula = factor(Pass) ~ factor(Weekly_Assessments_Given), 
##     family = binomial(link = "logit"), data = data1)
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -2.0393  -1.5518   0.7954   0.7954   0.8446  
## 
## Coefficients:
##                                   Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                        0.98852    0.07279  13.581   <2e-16 ***
## factor(Weekly_Assessments_Given)1  0.29713    0.18016   1.649   0.0991 .  
## factor(Weekly_Assessments_Given)2  0.40469    0.19993   2.024   0.0430 *  
## factor(Weekly_Assessments_Given)3 -0.14122    0.27079  -0.522   0.6020    
## factor(Weekly_Assessments_Given)4  0.95739    0.53945   1.775   0.0759 .  
## factor(Weekly_Assessments_Given)5  0.95739    1.07152   0.893   0.3716    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 1650.3  on 1462  degrees of freedom
## Residual deviance: 1639.3  on 1457  degrees of freedom
## AIC: 1651.3
## 
## Number of Fisher Scoring iterations: 4

when the number of weekly assessment is 2, it has significant effect on students’ performance in exit exam

Stratified on Grade

model3 <- glm(factor(Pass) ~ factor(NumExit),family=binomial(link='logit'),data=data1[data1$Grade=='PS',])
summary(model3)
## 
## Call:
## glm(formula = factor(Pass) ~ factor(NumExit), family = binomial(link = "logit"), 
##     data = data1[data1$Grade == "PS", ])
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -1.6719  -1.5015   0.8849   0.8849   1.2735  
## 
## Coefficients:
##                  Estimate Std. Error z value Pr(>|z|)    
## (Intercept)       0.73571    0.08966   8.206  2.3e-16 ***
## factor(NumExit)2  0.37794    0.19552   1.933   0.0532 .  
## factor(NumExit)3  0.36291    0.67267   0.540   0.5895    
## factor(NumExit)4 -0.95885    0.67679  -1.417   0.1565    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 946.85  on 766  degrees of freedom
## Residual deviance: 940.41  on 763  degrees of freedom
## AIC: 948.41
## 
## Number of Fisher Scoring iterations: 4
model4 <- glm(factor(Pass) ~ factor(NumExit),family=binomial(link='logit'),data=data1[data1$Grade=='PK',])
summary(model4)
## 
## Call:
## glm(formula = factor(Pass) ~ factor(NumExit), family = binomial(link = "logit"), 
##     data = data1[data1$Grade == "PK", ])
## 
## Deviance Residuals: 
##     Min       1Q   Median       3Q      Max  
## -2.1460   0.6512   0.6512   0.6512   0.6576  
## 
## Coefficients:
##                   Estimate Std. Error z value Pr(>|z|)    
## (Intercept)        1.44316    0.11468  12.585   <2e-16 ***
## factor(NumExit)2  -0.02177    0.22050  -0.099    0.921    
## factor(NumExit)3   0.75407    0.75413   1.000    0.317    
## factor(NumExit)4  13.12291  509.65214   0.026    0.979    
## factor(NumExit)6 -16.00922  882.74338  -0.018    0.986    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for binomial family taken to be 1)
## 
##     Null deviance: 676.13  on 695  degrees of freedom
## Residual deviance: 670.29  on 691  degrees of freedom
## AIC: 680.29
## 
## Number of Fisher Scoring iterations: 13

In a word, after strafying on Grade, we can see that when the grade is PK, the number of exit exam has no obviously effect on passing exit exams, while when the grade is PS, the number of exit exams has some effect on passing exit exam,which means that NumExit=2 will increase the odds of passing exit exam(s) to 1.46 when other varialbes hold constant.