10.03.2015 Views

Introduction to Survey Data Analysis - Survey Research Laboratory

Introduction to Survey Data Analysis - Survey Research Laboratory

Introduction to Survey Data Analysis - Survey Research Laboratory

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Nonignorable missing data<br />

• The pattern of data missingness is<br />

non-MAR.<br />

<strong>Survey</strong> <strong>Research</strong> Labora<strong>to</strong>ry<br />

Methods of Handling Missing <strong>Data</strong><br />

• Listwise (casewise) deletion: uses only<br />

complete cases<br />

• Pairwise deletion: uses all available cases<br />

• Dummy Variable Adjustment: Missing<br />

value indica<strong>to</strong>r method<br />

• Mean Substitution: substitute mean value<br />

computed from available cases (cf.<br />

unconditional or conditional)<br />

<strong>Survey</strong> <strong>Research</strong> Labora<strong>to</strong>ry<br />

Methods of Handling Missing <strong>Data</strong><br />

• Regression methods: predict value<br />

based on regression equation with<br />

other variables as predic<strong>to</strong>rs<br />

• Hot deck: identify the most similar<br />

case <strong>to</strong> the case with a missing and<br />

impute the value<br />

<strong>Survey</strong> <strong>Research</strong> Labora<strong>to</strong>ry<br />

6

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!