Descriptive and Causal-Comparative Research Designs

1. Descriptive and Causal-Comparative Research Designs

2. Four Types of Knowledge • Description • Prediction • Improvement • Explanation

3. Descriptive Research Method • Purpose: • Research in its most basic form involves the description of natural or man-made phenomena – their form, actions, changes over time, and similarities with other phenomena

4. Types of Descriptive Research • Descriptive • Involves making careful descriptions of educational phenomena • Relationship • Involves both describing phenomena and exploring the possible causal relationships between different phenomena (includes both causal-comparative and correlational) • Experimentation • Involves not only describing phenomena, but also manipulating these phenomena and determining the causal relationships between them (GBG, 13-14)

5. Tools of Descriptive Research • Standard Achievement Tests • Classroom observations instruments • Attitude Scales • Interview Schedules or Protocols • GBG (Chapters 7-9)

6. Types of Descriptive Research • Sample at One Point in Time • aka “cross-sectional studies” • Involves making careful descriptions of educational phenomena • Sample Over Time • aka “longitudinal studies” • Trend Studies • Cohort Studies • Panel Studies

7. Sample at One Point in Time • Involves nothing more than reporting the characteristics of one sample at one point in time • Examples: • Opinion polls • Surveys of people’s behavior • Perceptions and/or attitudes (politics, work place, etc.)

8. Planning a Descriptive Study • Quantitative Study • Formulate a research problem • State research hypotheses • Questions or objectives • Select an appropriate sample and measures • Collect and analyze the data • Report findings

9. Sample Over Time • Longitudinal Studies (LS): involve collecting data from a sample at different points in time in order to study changes or continuity in the sample’s characteristics • LS are difficult to implement, but they are essential for exploring problems in human development

10. Longitudinal Studies • Trend Studies • Describe change by selecting a different sample at each data collection point from a population that does not remain constant • Trend studies are useful for studying changes in general populations that change constantly in terms of the individuals who are members of the population • Example: use of graphing calculators in the teaching of high school mathematics

11. Longitudinal Studies • Cohort Studies • Describe change by selecting a different sample at each data collection point from a population that remains constant • Population would remain the same, but different individuals would be sampled each year • Examples: elementary school teachers who received California teaching certificates in 1992; high school completion rate of a single cohort [class of 1982]

12. Longitudinal Studies • Panel Studies • Involves selecting a sample at the outset of the study and then at each subsequent data collection point surveying the same sample • Ability to note changes in specific individuals and also explore possible reasons why these individuals have changed

13. Panel Studies • Disadvantages • Loss of subjects (especially when the study extends over a long period of time) • Respondents who remain in the sample tend to be a biased sample (respondents vs. non-respondents) • Advantages • Identifying who is changing and in what way • Ability to trace back to the events and characteristics of the individuals that might have contributed to the change

14. Causal-Comparative Research • Study of Relationships between variables • Educational research is done primarily to DESCRIBE educational phenomena or to EXPLORE relationships between different phenomena • Type of relationship that is of interest to educators is that involving CAUSE AND EFFECT • The discovery of cause-and-effect relationships is useful both for theory development and for educational improvement

15. Causal-Comparative Research • Simplest quantitative approach to exploring cause-and-effect relationships between phenomena • Examples: • Particular type of instruction improves students’ ability to solve problems, that knowledge can be used to develop a theory of problem-solving instruction • Can be used to develop an effective curriculum that incorporates this instruction in problem solving

16. Causal-Comparative Research • Advantages • Type of quantitative research that seeks to discover possible causes and effects of a behavior pattern or personal characteristic by comparing individuals in whom it is present with individuals in whom it is absent or present to a lesser degree • AKA “ex post fact research” – causes are studied after they presumably have exerted their effect on another variable • Cause-and-effect relationships ARE NOT amenable to experimental manipulation • Can examine many relationships in a single research project

17. Causal-Comparative Research • Disadvantages • Difficult to establish causality on the basis of the collected data; determining causal patterns with any degree of certainty is difficulty • An observed relationship between variables A and B can mean that A causes B, B causes A, or a third variable C causes both A and B