Lecture 7 Nonexperimental Design Research Methods and Statistics 1

Research Design A research design is the overall structure that researchers use to obtain answers to their research questions. 2 Randomized Experimental Quasi- Experimental ExperimentalNon-Experimental Causal Comparative Correlational Descriptive/Explanatory

Non-Experimental Designs: Descriptive/Exploratory(Survey) 3 Descriptive/exploratory designs aim to describe characteristics of individuals or of a phenomenon as they occur naturally. Characteristics of descriptive/exploratory designs -Data is collected to describe a phenomenon or human characteristic (e.g. abilities, opinions, attitudes, beliefs, experience, knowledge) -Data is typically collected from a sample drawn from a population.

Non-Experimental Designs: Descriptive/Exploratory(Survey) Characteristics of descriptive/exploratory designs (continued) -The most common way to collect data is by asking questions; (e.g. though questionnaires, tests, interviews) -The responses to these questions constitute the data of the study -Researchers do not manipulate variables 4

Non-Experimental Designs: Correlational Correlational designs aim to examine relationships between 2 or more quantitative variables in one group. Characteristics of Correlational Designs -Investigating whether and to what degree quantitative variables are related -Investigating whether a quantitative variable(s) predict the outcome/value of another quantitative variable. -Investigating whether there is a cause-effect relationship between variables 5

Non-Experimental Designs: Correlational Strengths -Fairly easy to conduct. -Potential foundation for future, experimental studies Limitations -Limited in establishing causal relationships because of the lack of manipulation, control and randomization 6

Correlational Designs: Research Questions Relationship: (correlation) -What is the relationship between trust in supervisor and turnover intention of employees? Predictive: (regression, and with two variables simple regression) -To what extent does public service motivation predict individual performance in government? Causal: (i.e. if there is a policy you could collect data before and after implementation of the policy) -What effect does diversity management have on job satisfaction of minority employees in government? 7

Non-Experimental Designs: Causal- Comparative (Ex-Post Facto) Causal-comparative designs attempt to determine differences that already exist among groups. Characteristics of causal-comparative designs -Groups already differ on some dependent variable: Ex. One group may possess a characteristic that the other does not or each group possesses the characteristic but in differing amounts -Researcher attempts to identify retrospectively a major factor (the independent variable) that led to group differences. 8

Causal-Comparative Designs: Example Research Questions Are female employees more satisfied with their job than male employees when their agency has family-friendly policies and programs? Will minority employees show higher levels of job satisfaction than nonminority employees when their agency manages demographic diversity more effectively? 9

The Time Dimension: Cross-Sectional vs. Longitudinal Designs Cross-Sectional data: collected from different groups at the same point in time. Longitudinal Data: collected from the same group at different points in time. 10 Sample A Sample B Sample C TIME Sample A Measure 1 Sample A Measure 2 Sample A Measure 3

Class Exercise For each of the following research questions describe the design and data collecting strategy you would propose to investigate the issue. Make your design and data collection as practical and moral as possible. 1)What were the social and political attitudes of the voters who supported the two major-party candidates in the 2004 presidential election? 2)Why do some states have the death penalty whereas others do not? 3)What is the effect of ballot position on voter choice in a city election in which there are no incumbents and no party labels? 4)What might be the effect of a 50 cent-a-gallon increase in the price of gasoline on the use of public transportation? 5)Can imposing a refundable deposit (such as applied to glass and plastic bottles in some states) on each new tire sold in a state help reduce the number of used tires dumped illegally? 11