Education 795 Class Notes

Introduction and Overview

Note set 1

Welcome!

• Overview of course goals, structure, and organization

• Discussion of course goals and processes

Course Goals

• Upon completion of this course you will be able to use statistical software and appropriate statistical reasoning to make sense out of a body of quantitative data

• We will also emphasize developing the skills needed to present original research findings to professional audiences

Course Structure

• Wednesday sessions provide an opportunity to present and review concepts with the addition of the wireless laptop lab

• Thursday sessions provide an opportunity to explore concepts and practice computing skills

Organization of the Course• Review and extension of the statistical

concepts and methods introduced in introductory educational statistics courses

• Research design, analysis issues, and introduction to factor analysis, scale construction, and advanced predictive techniques

• Extension and application of the topics previously introduced, with an emphasis on regression-based approaches

Resource Organization

Now Later

Ed 793 notesWeb resources

Beware

• We will be flipping back and forth between the first half of the Pedhazur & Pedhazur book. The first half represents the design and theoretical underpinnings of our focus, while the second half represents the analysis and interpretation piece.

• 1998 Survey of students entering the University of Michigan• 1986-1990 national, multi-institutional longitudinal survey of

students in college• NELS 88-2002, a longitudinal, nationally representative database

that addresses the K-12—higher ed transition. You will need some training for this dataset so maybe pick this up at the end of the term

• Data base of your choosing to provide better alignment with your research interests; we can help identify data resources

Data Bases for Computing Sessions

IRB review is required for student-provided databases (we have completed this for the data resources we are bringing to the class). We can help you develop a plan for the protection of human subjects to facilitate IRB review.

Brief Review of 793 Material

• Descriptive Statistics– central tendency, spread, shape– frequencies– crosstabs

• Inferential Statistics– one-sample test for means– two-sample test for means– paired sample test– Chi-square test for relationships (nom./ord. data)– ANOVA (test means of more than 2 groups)

Review of 793 Material

• Describing relationships– plots– correlations

• Prediction– ANCOVA (introduce statistical control)– multiple regression (we will pick up here

and elaborate)

Review of Simple Linear Regression from the Beginning

• Example: Using the UM98 data, predict whether students think promoting racial understanding is important based on their family income.– Dependent: promote racial understanding

(not important – very important)– Independent: Family Income (continuous)

Descriptive Results

Mean SD

• Prom Rac Under 2.26 .92

• Income 8.11 3.20

• Correlation = -.044 (p=.006)

Plot of Relationships

1

2

3

4

PR

OM

OT

E R

AC

IAL

UN

DE

RS

TAN

DIN

G 2

1 2 3 4 5 6 7 8 9 10 11 12 13 14

PARENTAL INCOME

Linear Fit

Bivariate Fit of PROMOTE RACIAL UNDERSTANDING 2 By PARENTAL INCOME

Doesn’t help much until we ask for the fit of the regression line

Graphics courtesy of JMP5

Regression Results

Regression Results

This equals the correlation in a simple linear regression

Interpretation

• Is income a significant predictor of how important a student believes it is to promote racial understanding?

• What is the relationship?

• How much variance did we explain?

Questions

• Questions?

For Next Week

• Read Pedhazur Ch 9 p 180-187 for a discussion of the “Role of Theory in Research”

• For Review of Simple Linear Regression Skim Pedhazur Ch 17 p 366-388

• For Review of Multiple Regression Read Ch 18 p 413-420