DABB 04 13 Hierarchical Regression Handout

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Data Analysis Brown Bag April 2013

Model Building: Hierarchical Regression Data Analysis Brown Bag February 2013

Karen Grace-Martin

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

The Goal Choose variables that: 1. Answers the Research Question 2. Reflects the Real Relationships and Form of the Data

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

The Top-Down Strategy 1. Fit a full model, including proposed interactions 2. Refine the model to account for assumptions, better fit 3. Reduce the model by removing non-significant effects

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

The Step-Up Strategy 1. Start with a basic model 2. Add and test predictors to improve model fit 3. Adjust the final model, if necessary, to account for assumptions

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Hierarchical Regression 0.1 Choose Variables 0.2 Run Univariate and Bivariate Descriptives, including graphs •

Run a Model with Control Variables



Add Key Predictors



Add Interactions and/or Curvature



Adjust the final model, if necessary, to account for assumptions and data issues

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Choosing Variables

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Choosing Variables

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Choosing Variables Considerations 1. 2. 3. 4.

How well it measures the construct Distribution and missing values Relationship to Y Relationship to other Xs

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Distribution and Missing Values

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Distribution and Missing Values

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Relationship to Y

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Relationship to Y

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Relationship to Each Other

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Relationship to Each Other

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Chosen Variables Block 1: Demographic Controls 1. 2. 3.

Marital Status: Married Divorced Separated Widowed MaleDummy NumberBioStepAdoptChildHH2000

Block 2: Psychological and Situational Controls: 1. 2. 3. 4.

CESD2000Total WorkTimeHrsperWkPastCalYr2000cat4 UnemployedWksPastCal2000cont PovertyStatus2000c2

Block 3: Key Predictors 1.

Religious Attendance in 5 Categories

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Block 1: Demographic Controls R2 = .027 Adj. R2 = .024

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Block 2: Psychological and Situational Controls R2 = .186 Adj. R2 = .184

Decision: Keep all variables ©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Block 3: Key Predictors R2 = .002 Adj. R2 = .001

R2 = .008 Adj. R2 = .006

Decision: Treat Religious Attendance as Categorical ©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Build Blocks R2 = .025 Adj. R2 = .023

©2013 K Grace-Martin

R2 = .188 Adj. R2 = .183

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Build Blocks R2 = .186 Adj. R2 = .184

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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Data Analysis Brown Bag April 2013

Build Blocks R2 = .186 Adj. R2 = .184

©2013 K Grace-Martin

http://TheAnalysisFactor.com

R2 = .188 Adj. R2 = .184

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Data Analysis Brown Bag April 2013

Next Steps 1. Possibly Add Interactions or Quadratic Terms 2. Test Assumptions 3. Check Data Issues

©2013 K Grace-Martin

http://TheAnalysisFactor.com

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