PY 603 Advanced Statistics II

1
PY 603 Advanced Statistics II

• TR 1230-145pm
• 232 Gordon Palmer Hall
• Jamie DeCoster

2
Introduction to Regression

• Travel survey
• Syllabus
• Prerequisites (PY 602 topics)
• Describing a data set
• Steps to perform a hypothesis test
• Hypothesis tests of a point estimate

3
Prerequisites (PY 602 topics)

• Knowledge of ANOVA
• Knowledge of SPSS
• Knowledge of Excel
• Knowledge of Word equation editor

4
Describing a Data Set

• Data source vs. data set
• Cases
• Variables
• Unit of analysis
• Numeric vs. categorical variables

5
Steps to Describe a Data Set

• Provide a general description of the data set
• Describe the subject population
• Report the unit of analysis for the data set
• Name your variables
• Describe what the variable measures
• State the units of numeric variables or the
  groups for categorical variables

6
Steps to Perform a Hypothesis Test

• Determine null and alternative hypotheses
• Select a sample
• Collect data discriminating the hypotheses
• Compute a test statistic
• Determine the probability of getting the observed
  statistic if the null was true
• State whether you reject or fail to reject the
  null hypothesis

7
Hypothesis Test of a Point Estimate

• Tests whether an estimated value is significantly
  different from a constant
• Commonly performed in regression
• Values of estimates
• Slopes of regression lines
• General form

8
Reporting a Hypothesis Test of a Point Estimate

• State the null and alternative hypotheses
• Report the estimate
• Report the standard error of the estimate
• Report the df associated with the standard error
• Calculate the t statistic
• Report the p-value for the t
• State your conclusion