Survey Analysis: An introduction Flashcards
What are the 4 key features of multivariate analysis?
- Relationship between more than one variable at a time
- Cross-tabulation (nominal/ordinal data)
- Counts in categories
- Questionnaire Data
What is the general form of a 2-by-2 cross tabulation?
- Dependent (y) variables as columns
- Predictor (x) variables as rows
- Examine row percentage to see patten (Marsh, 1988)
How can you graphically represent a 2-by-2 cross tabulation?
Clustered Bar Charts
Pie Charts
What are Casual models?
Models for developing explanatory theories of cause and effect
What is a problem with casual models?
Possible alternative and conflicting explanations
- need to evaluate extent alternative hypothesised models are consistent with empirically observed data
What are the 3 conditions casuality implies?
Covariance
- Variation in x should always result in variations in y
Temporal Precedence
- Variations in x should always occur before variations in y
Production
- Changes in x should really be the cause of the changes in y
What is Chi Squared test?
A statistical test commonly used to compare observed data with data we would expect to obtain according to a specific hypothesis.
The Chi Square statistic compares the tallies or counts of categorical responses between two (or more) independent groups
What is Cramers V?
Cramer’s V is a way of calculating correlation in tables which have more than 2x2 rows and columns
Chi-square says that there is a significant relationship between variables, but it does not say just how significant and important this is. Cramer’s V is a post-test to give this additional information.
Cramer’s V varies between 0 and 1. Close to 0 it shows little association between variables. Close to 1, it indicates a strong association.
What is a spurious relationship?
A relationship between z and y, when controlled for x
