Map of Course Sections by Location

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Course sections are listed by location. Internet sections were placed near their respective institution location. The number of students in the full data set is 5443, the number of removed students is 4696 and the model data set is 745.

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Note. Data for this study was collected by the Wyoming Community College Commission (WCCC) from 2012 to 2023, encompassing 5448 students who enrolled in CCC. Several criteria were applied to create the analytic sample. Only students’ first CCC attempt was included, concurrent enrollment sections taught in high schools, all dual enrollment CCC students, students with HS GPA which was larger than 4.0, and students with missing data were listwise deleted. The analysis focused on CCC sections from the 2013-2014 academic year onward, allowing summer 2012 through summer 2014 to serve as a lookback period for capturing students’ precalculus coursework history. Sections with fewer than three students were removed to allow for adequate sample sizes for multilevel modeling (Clarke, 2008). The final analytic sample consisted of 745 students in 91 course sections across 5 of Wyoming’s 7 CCs. The smallest section size was 3, and the largest was 22 students.

Model Specification

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Model Diagram

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Level 1 (student) intercept is represented by the \(1_{1}\) triangle on the left, with level 1 predictors below in rectangles; Level 2 predictors are arranged horizontally along the top in rectangles with the level 2 intercept represented with the \(1_{2}\) triangle. Cross-level interaction term edges and their coefficient labels are color coded with their β-nodes. The intercept varies randomly across sections, indicated by the random effect \(u_{0j}\). Variables in bold font are centered within section (cwc), variables bold-italic font are grand mean centered (gmc). Parameter estimates without parentheses are significant (p≤0.05) and within parentheses are non-significant (p>0.05).

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Multilevel Logistic Regression Model - Hierarchical Form

The model can be written in hierarchical form with the student \(\beta\) level coefficients, which are then written in terms of section \(\gamma\) level coefficients. The random effect for the intercept is \(u_{0j}\) and there are no random slopes. There are two student-level interaction terms and two cross-level interaction terms.

Level 1 Model:

\[ \begin{aligned} \log\left(\frac{P(Y_{ij} = \text{Pass})}{P(Y_{ij} = \text{Fail})}\right) &= \beta_{0j}+\beta_{1j} (\text{HSPGA})_{cwc}+\beta_{2j} (\text{max actmath})_{cwc} \\ &\quad + \beta_{3j} (\text{years calc since HS})_{cwc} + \beta_{4j} (\text{math courses below 2200})_{cwc} \\ &\quad + \beta_{5j} (\text{female})+\beta_{6j} (\text{concurrent prereq})_{cwc} + \beta_{7j} (\text{URM}) \\ &\quad + \beta_{8j} (\text{HSGPA})_{cwc}×(\text{years calc since HS})_{cwc} \\ &\quad +\beta_{9j} (\text{concurrent prereq})_{cwc} ×(\text{max actmath})_{cwc} \end{aligned} \]

Level 2 Model:

\[ \begin{aligned} &\quad \beta_{0j} = γ_{00} + \gamma_{01} (\text{HSGPA})_{gmc}+\gamma_{02} (\text{coreqcollege}) +u_{0j} \\ &\quad \beta_{1j} =\gamma_{10} \\ &\quad \beta_{2j} =\gamma_{20} \\ &\quad \beta_{3j} =\gamma_{30} \\ &\quad \beta_{4j} =\gamma_{40}+\gamma_{41} (\text{coreq college}) \\ &\quad \beta_{5j}=\gamma_{50} \\ &\quad \beta_{6j}=\gamma_{60} \\ &\quad \beta_{7j}=\gamma_{70}+\gamma_{71} (\text{HSGPA})_{gmc}\\ &\quad \beta_{8j}=\gamma_{80} \\ &\quad \beta_{9j}=\gamma_{90} \end{aligned} \]

Multilevel Logistic Regression Model - Combined Form

Substituting the section-level \(\beta\) coefficient equations into the student-level equation results in a representation of the model in combined form:

\[\begin{aligned} \log\left(\frac{P(Y_{ij} = \text{Pass})}{P(Y_{ij} = \text{Fail})}\right) &= \gamma_{00} + \gamma_{01}(\text{HSGPA})_{gmc} + \gamma_{02}(\text{CoreqCollege}) \\ &\quad + \gamma_{10}(\text{HSGPA})_{cwc} + \gamma_{20}(\text{ACTMath})_{cwc} + \gamma_{30}(\text{YearsCalc})_{cwc} \\ &\quad + \gamma_{40}(\text{MathCourses})_{cwc} + \gamma_{41}(\text{MathCourses})_{cwc} \times (\text{CoreqCollege}) \\ &\quad + \gamma_{50}(\text{Female}) + \gamma_{60}(\text{ConcurrentPrereq})_{cwc} + \gamma_{70}(\text{URM}) \\ &\quad + \gamma_{71}(\text{URM}) \times (\text{HSGPA})_{gmc} + \gamma_{80}(\text{HSGPA})_{cwc} \times (\text{YearsCalc})_{cwc} \\ &\quad + \gamma_{90}(\text{ConcurrentPrereq})_{cwc} \times (\text{ACTMath})_{cwc} + u_{0j} \end{aligned}\]

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Model Structure

Component Description
Level 1 Structure \(\log\left(\frac{P(Pass)}{P(Fail)}\right) = \beta_{0j} + \sum\beta_{qj}X_{qij}\)
Level 2 Structure \(\beta_{qj}=\gamma_{q0}+\sum\gamma_{qs}W_{sj}+u_{qj}\)
Level 1 Predictors HSGPA, ACT Math, Years since HS, Math Courses, Female, Concurrent Prereq, URM
Level 2 Predictors HSGPA (gmc), Coreq College
Level 1 Interactions HSGPA×Years, Concurrent×ACTMath
Cross Level Interactions Math Courses×Coreq, URM×HSGPA(gmc)
Random Effect \(u_{0j} \sim N(0, \tau_{00}^2)\)

Fixed Effects

Effect Parameter Level Centering
Intercept \(\gamma_{00}\)
HSGPA (gmc) \(\gamma_{01}\) Section Grand-Mean
Coreq College \(\gamma_{02}\) Section None
HSGPA (cwc) \(\gamma_{10}\) Student Section-Mean
ACT Math (cwc) \(\gamma_{20}\) Student Section-Mean
Years since HS (cwc) \(\gamma_{30}\) Student Section-Mean
Math Courses (cwc) \(\gamma_{40}\) Student Section-Mean
Female \(\gamma_{50}\) Student None
Concurrent Prereq (cwc) \(\gamma_{60}\) Student Section-Mean
URM \(\gamma_{70}\) Student None

Interactions

Interaction Parameter Level
Math Courses (cwc) × Coreq College \(\gamma_{41}\) Cross-Level
URM × HSGPA (gmc) \(\gamma_{71}\) Cross-Level
HSGPA (cwc) × Years since HS (cwc) \(\gamma_{80}\) Student-Level
Concurrent Prereq (cwc) × ACT Math (cwc) \(\gamma_{90}\) Student-level

Student-Level Descriptive Statistics

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Continuous Variables

Variable N M SD Min Max
HS.GPA 745 3.49 0.44 1.80 4.00
ACT.Math 745 24.10 3.57 13.00 34.00
Years.since.HS 745 1.26 1.28 0.21 8.21
Math.prereqs 745 1.44 1.16 0.00 7.00

Categorical Variables

Variable Yes No Percent_Yes Percent_No
Female 288 457 38.7 61.3
URM 139 606 18.7 81.3
Concurrent prereq 148 597 19.9 80.1
Coreq college 278 467 37.3 62.7
Pass 537 208 72.1 27.9

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Gender Distribution

URM Status Distribution

Concurrent Prerequisite Distribution

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HS GPA Distribution

ACT Math Distribution

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Years Since HS Distribution

Math Prerequisites Distribution

Section-Level Statistics

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Overall Section Statistics

Statistic Value
Total Sections 91.0
Total Students 745.0
Mean Section Size 8.2
SD Section Size 4.6
Min Section Size 3.0
Max Section Size 22.0

Section Mean Distributions

Variable M SD Min Max
Mean HS GPA 3.460 0.210 2.84 3.94
Mean ACT Math 24.060 1.860 18.00 27.80
Mean Years Since HS 1.410 0.840 0.21 4.75
Mean Math Prerequisites 1.440 0.620 0.00 3.00
Prop. Concurrent Prereq 0.178 0.253 0.00 1.00

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Group Sizes

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Section-Level Pass Rates Distribution

Section Mean High School GPA

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Section Mean Mean ACT Math

Section Mean Years Since HS

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Section Mean Number of Math Prerequisites

Section Mean Proportion Concurrent Prerequisite

Comparative Analysis

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Pass/Fail Distribution

Pass Rate by Time & Prerequisites

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Pass Rate by Academic Preparation

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Pass Rate by Gender and URM Status

Pass Rate by Categorical Variables

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Pass Rate Differences by Categorical Variables

Significant Main Effects and Interactions

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Model Diagram with Significant Effects

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Level 1 (student) intercept is represented by the \(1_{1}\) triangle on the left, with level 1 predictors below in rectangles; Level 2 predictors are arranged horizontally along the top in rectangles with the level 2 intercept represented with the \(1_{2}\) triangle. Cross-level interaction term edges and their coefficient labels are color coded with their β-nodes. The intercept varies randomly across sections, indicated by the random effect \(u_{0j}\). Variables in bold font are centered within section (cwc), variables bold-italic font are grand mean centered (gmc). Parameter estimates without parentheses are significant (p≤0.05) and within parentheses are non-significant (p>0.05). There were three main effects and four interactions that were significant in the model. Shaded ribbon around predicted probability represents a 95% confidence interval. Horizontal axis spans range of data for variable.

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Course-Level Effect: HSGPA (gmc)

The main effect of HSGPA (gmc) was significant in the model. This represents the influence of mean course-section HSGPA compared to grand mean HSGPA.

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Student-Level Effect: HSGPA (cwc)

The student-level main effect of HSGPA (cwc) was significant in the model. This represents the influence of the difference between a student’s HSGPA and their course-section mean.

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Student-Level Effect: math prereqs (cwc)

The main effect of math prereqs (cwc) was significant in the model. This represents the influence of the difference between the number of prerequisite math courses a student took and their course section mean.

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Student-Level Interaction: concurrent prereq (cwc) x ACT Math (cwc)

The student-level interactionconcurrent prereq (cwc) x ACT Math (cwc) was significant in the model. Slider bar goes two standard deviations on each side of the mean of ACT Math (cwc).

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Student-Level Interaction: HSGPA (cwc) x years since HS (cwc)

The student-level interaction HSGPA (cwc) x years since HS (cwc) was significant in the model. Slider bar goes two standard deviations on each side of the mean of HSGPA (cwc).

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Cross-Level Interaction: coreq college x math prereqs (cwc)

The the cross-level interaction coreq college x math prereqs (cwc) was significant. Button toggles coreq college status.

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Cross-Level Interaction: URM x HSGPA (gmc)

The the cross-level interaction URM x HSGPA (gmc) was significant. Button toggles URM status.

Model Summary and Assumption Testing

Testing assumptions for multilevel logistic regression: multicollinearity, the log odds of the dependent variable needs to be linearly related to the independent variables, and sample sizes must be sufficient to have a minimum number of cases in each outcome.

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ICC

Intraclass Correlation Coefficients
Value
Component ICC
ICC_adjusted 0.114
ICC_conditional 0.114
ICC_unadjusted 0.114

Null Model Summary

Null Model Summary
Effect Group Term Estimate SE z p
Fixed Effects
fixed NA (Intercept) 1.017 0.115 8.823 < 0.001
Random Effects
ran_pars Location_Term_Institution sd__(Intercept) 0.650 NA NA

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Full model summary

Full Model Fixed Effects
Term Estimate SE z p
(Intercept) 1.174 0.177 6.613 < 0.001
HSGPA_cwc 1.608 0.255 6.302 < 0.001
years_calc_since_HS_cwc -0.054 0.093 -0.585 0.559
HSGPA_gmc 2.912 0.642 4.537 < 0.001
URM -0.215 0.236 -0.911 0.362
coreqcollege -0.189 0.240 -0.789 0.43
math_courses_below_2200_cwc 0.305 0.136 2.237 < 0.05
concurrent_prereq_cwc -0.474 0.314 -1.508 0.131
max_actmath_cwc 0.053 0.035 1.524 0.128
female -0.003 0.203 -0.014 0.989
HSGPA_cwc:years_calc_since_HS_cwc -0.798 0.226 -3.526 < 0.001
HSGPA_gmc:URM -2.738 1.200 -2.281 < 0.05
coreqcollege:math_courses_below_2200_cwc -0.552 0.189 -2.922 < 0.01
concurrent_prereq_cwc:max_actmath_cwc 0.203 0.100 2.035 < 0.05

Compare Null vs Full Model

Model Comparison
Model npar AIC BIC logLik deviance Chisq df Pr..Chisq.
Null Model 2 873.61 882.83 -434.8 869.61 NA NA NA
Full Model 15 802.80 872.00 -386.4 772.80 96.81 13 < 0.001

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VIF

Variance Inflation Factors
Variable VIF
HSGPA_cwc 1.209
years_calc_since_HS_cwc 1.270
HSGPA_gmc 1.227
URM 1.081
coreqcollege 1.052
math_courses_below_2200_cwc 2.284
concurrent_prereq_cwc 1.126
max_actmath_cwc 1.499
female 1.100
HSGPA_cwc:years_calc_since_HS_cwc 1.179
HSGPA_gmc:URM 1.249
coreqcollege:math_courses_below_2200_cwc 1.671
concurrent_prereq_cwc:max_actmath_cwc 1.061

Correlation Matrix of Continuous Variables

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HSGPA_cwc

years_calc_since_HS_cwc

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HSGPA_gmc

math_courses_below_2200_cwc

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concurrent_prereq_cwc

max_actmath_cwc

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Pearson Residual Plot

DHARMA Residual Plot

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DHARMA QQ Residual Plot

Histogram of DHARMA Residuals

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Check For Influential Groups