Chronic Absenteeism Rate Prediction: A Data Science Case Study
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The Chronic Absenteeism Rate Prediction (CARP) project analyzes demographic factors to predict chronic absenteeism in K-12 students, utilizing datasets from the California Department of Education and the U.S. Census Bureau. Key findings indicate that race, educational attainment, marital status, and income are the strongest predictors, with a more effective decision tree ensemble model outperforming a neural network. Future work aims to expand the scope of analysis and refine data extraction and modeling techniques.
Chronic Absenteeism Rate Prediction: A Data Science Case Study
- 1. © 2019 Iver Band© 2019 Iver Band Chronic Absenteeism Rate Prediction (CARP) Coursera Advanced Data Science with IBM Specialization Capstone Project Iver Band December, 2019
- 2. © 2019 Iver Band© 2019 Iver Band Agenda ● Use Case ● Source Data Sets ● Architectural Overview ● Data Quality Assessment ● Data Visualization ● Data Exploration ● Initial Feature Engineering ● Model Performance Indicator ● Core Concepts ● Algorithms ● Frameworks ● Feature Engineering Experiment ● Model Performance Evaluation ● Conclusion
- 3. © 2019 Iver Band © 2019 Iver Band Chronic Absenteeism Rate Prediction (CARP) Use Case ● Chronic absenteeism occurs when a student in grades K-12 misses 10% or more of the school year for any reason ● It is a strong predictor of low academic achievement. ● CARP is for data scientists supporting educational and social services administrators and policymakers in answering the following questions: ○ What demographic factors predict the rate of chronic absenteeism? ○ Can we use demographic data to predict chronic absenteeism rates?
- 4. © 2019 Iver Band © 2019 Iver Band Source Data Sets ● 2018 Chronic Absenteeism Data from California Department of Education ○ Counts of total students and chronically absent K-12 students by census tract in Los Angeles County, California, USA ● US Census Bureau American Community Survey 2013-2017 ○ Statistics on potential predictors of 2018 chronic absenteeism rates: Median Income Employment Status Race Length of Commute Educational Attainment Disability Geographic Mobility Marital Status Health Insurance Status Citizenship and Nativity English Language Mastery
- 5. © 2019 Iver Band© 2019 Iver Band data.census.gov www.cde.ca.gov Personal Laptop Dataplatform.ibm.com object store CARP-ETL: Join and otherwise prepare data CARP-EXP: Explore and visualize data CARP-DNN: Define, train, and test deep neural network regressor CARP-DTE: Define, train, and test AdaBoost Decision Tree Regressor CARP-ME: Evaluate and compare model performance US Census Bureau California Dept of Education Data Sources: Jupyter Notebooks: Architectural Overview
- 6. © 2019 Iver Band© 2019 Iver Band Data Quality Assessment ● Determined percentage of rows with missing or non- numeric data in ○ All 11 input data sets prior to cleansing ○ The joined data set ● Primary issue is 84% coverage of LA County census tracts, ● Data about 2158 census tracts was available for modeling
- 7. © 2019 Iver Band© 2019 Iver Band ● Visualized distribution of chronic absenteeism percentages with ○ Histogram ○ Kernel Density Estimate ○ Rug plot ● Distribution is roughly normal, with positive skewness Data Visualization
- 8. © 2019 Iver Band© 2019 Iver Band Data Visualization ● Visualized geographic distribution of chronic absenteeism rates with a choropleth map ● Adjacent or close census tracts tend to have similar rates
- 9. © 2019 Iver Band© 2019 Iver Band Data Exploration ● Visualized relationship of top 15 correlates per r2 score using pair plots with regression lines ● Read left to right, then top to bottom ● Race, educational attainment, marital status and income are the strongest predictors ● Prediction strength declines sharply after the top five predictors
- 10. © 2019 Iver Band © 2019 Iver Band Initial Feature Engineering ● Converted counts into percentages in ○ California Department of Education chronic absenteeism data set ○ Nearly all of the American Community Survey data sets ● Joined all twelve data sets by six-digit US census tract number, which is unique with each county ● For deep neural network model only ○ Calculated r2 for each predictor/target variable pair ○ Input only the top fifteen predictors ○ Scaled all data to have a mean of zero and a standard deviation of 1
- 11. © 2019 Iver Band© 2019 Iver Band Model Performance Indicator Coefficient of Determination (r2 ) ● Measures the extent to which the predicted rates reflect the total variability of the actual rates ● Disproportionately penalizes large errors ● Prevents errors with opposing signs from cancelling each other out Formula
- 12. © 2019 Iver Band© 2019 Iver Band Core Concept: Neural Network Feed Forward Back Propagation • Feed forward: prediction by computing the value of each node, layer-by-layer, based on multiplying the nodes in the previous layer by a set of weights, adding the products and a bias, and applying a nonlinear activation function • Back propagation: adjusting the weights and bias by differentiating the feed forward function to determine its slope, and applying gradient descent (next slide). Image from https://victorzhou.com/blog/intro-to-neural-networks/
- 13. © 2019 Iver Band© 2019 Iver Band Core Concept: Gradient Descent for Neural Network Model Training • Imagine trying to find the deepest valley in a deep fog • Altitude is loss function, which compares the predicted value to the actual value • The size of the step you take is the learning rate • Descending the valley is gradient descent • Your location in n-dimensional space is determined by using model weights and the loss function as coordinates • The model-fitting algorithm repeatedly determines the gradient (slope) of the loss and adjusts model weights and biases to descend the gradient Text and picture adapted from https://mc.ai/stochastic-gradient-descent-in-plain-english/
- 14. © 2019 Iver Band© 2019 Iver Band Core Concept: CART* for Decision Tree Modeling Do I play golf today? Yes or No? … Build next leaf with decision criteria with lowest Gini score: Adapted from: https://sefiks.com/2018/08/27/a-step-by-step-cart-decision-tree-example/*Classification and Regression Trees
- 15. © 2019 Iver Band© 2019 Iver Band Algorithms Feed-Forward Neural Network ● Dimensions of each layer ○ 15-->11-->7-->1 ● RELU Activation for all nodes ● f(x) = 0 if x <=0 ● f(x) = x otherwise ● Adam Optimizer ○ 0.01 learning rate ○ 0.001 decay ○ Mean squared error loss metric ● Batch size = 12 ● 25-40 epochs (passes through data) ● Early stopping for training runs that don’t converge ● Attributes chosen after wide experimentation Decision Tree Ensemble ● AdaBoost with decision tree as weak learner o Repeatedly builds decision trees, weighting them to improve weakest predictions o Squared error loss metric ● Method chosen after experimentation with linear regression and standalone decision tree regression, as well as other decision tree ensembles, such as random forest
- 16. © 2019 Iver Band© 2019 Iver Band Frameworks All Python-based Purpose Frameworks Interactive Development Jupyter within IBM Watson Studio Data Manipulation and Computation Numpy, Pandas, Geopandas Data Visualization Matplotlib, Seaborn, Descartes Neural Network Modeling Keras with TensorFlow backend Data Scaling, Model Scoring and Decision Tree Ensemble Modeling Scikit-Learn
- 17. © 2019 Iver Band © 2019 Iver Band Feature Engineering Experiment ● Choropleth map shows adjacent census tracts tend to have similar chronic absenteeism rates ● Many adjacent or nearby census tracts in LA County appear to have similar or sequential census tract numbers ● Therefore, would including the six-digit census tract number as a predictor variable, in addition to its role as a key, improve model performance? ● Unfortunately not. The census tract number is among the weakest of the predictor variables examined, based on ○ The pairwise r2 score ○ No performance change for the Decision Tree Ensemble model
- 18. © 2019 Iver Band© 2019 Iver Band Model Performance Evaluation ● Tested both models with five rounds of randomized shuffle-split with 80/20 train-test ratio ● Chose randomized shuffle-split over cross-validation to retain finer control over size of split ○ Before tuning, got good performance only with 90/10 train-test split ○ Future work could use cross- validation ● The Decision Tree Ensemble is clearly a stronger predictor than the Neural Network ● To avoid outliers, chose iteration with median performance of stronger model for further evaluation
- 19. © 2019 Iver Band© 2019 Iver Band Model Performance Evaluation ● Compared residuals of predictions using superimposed histograms ● For about 90% of test cases in its median-performing iteration, Decision Tree Ensemble predicted chronic absenteeism rates within 5%
- 20. © 2019 Iver Band© 2019 Iver Band Model Performance Evaluation ● Used a scatter plot with an identity and +/- 5% lines to visualize deviations of predicted chronic absenteeism rates from actual values ● Result is consistent with residual histograms
- 21. © 2019 Iver Band © 2019 Iver Band Conclusion ● What demographic factors predict the rate of chronic absenteeism? ○ For the years studied, race, educational attainment, marital status and income are the strongest predictors of chronic absenteeism in LA County, California, USA ● Can we use public demographic data to predict chronic absenteeism rates? ○ Yes, for the years studied, well enough to identify areas with highest future risk and, perhaps, implement mitigating measures ● Opportunities for future work ○ Expand scope to include additional geographic areas, years, and predictor variables ○ Further automate data extraction and transformation ○ Consider additional algorithms, e.g. PCA, XGBoost, Polynomial Regression ○ Explore outliers where rate is more or less than expected ○ Explore effects of programs to mitigate chronic absenteeism o Links https://github.com/IverBand/carp https://www.coursera.org/specializations/advanced-data-science-ibm