Nonexperimental quantitative design
- 2. Nonexperimental Quantitative Design A study that measures or observes subjects without attempting to introduce a treatment
- 3. Nonexperimental Quantative Design Correctional Design • A study where the researcher collects data of two or more variables • Correlation refers to the degree two variables consistently vary in the same or opposite direction Descriptive Design • Research carried out to describe some phenomenon as it exists • Doest not involve correlations of two or more variables • The purpose of the study is to observe, describe and document aspects of a situation as it naturally occurs
- 4. Correlation can be positive or negative when variables vary in the same direction (positive correlation) or in opposite directions (negative correlation). Example of a positive correlation: student grades and SAT scores (on average) Example of negative correlation: low grades and low SAT scores (on average)
- 5. Correlation coefficient – statistic indicating the degree to which two variables are correlated Perfect negative correlation perfect positive correlation ranges in value +1.0 to -1.0 0 indicates that the variables are unrelated Example: date of birth and age are -1.0 because if you know one, you can predict the other
- 7. Different kinds of variables: • Continuous variable – variables such as age, height, or test scores, that can take a wide or infinite number of values • Categorical variable – variables such as gender or ethnicity that have a limited number of value, such as a dichotomous variable. • Dichotomous variable – can only take on two values, such as gender, on-off, night-day.
- 8. Advantages Vs disadvantages (correlation Design) • There is no artificial alteration, researchers study phenomena as it exists. • They help us decide what variables are worth further study in experiments. • They allow researchers to learn about many variables at once (matrix). • Correlation does not measure cause • Does not allow researchers to come to any conclusions about cause and effect
- 9. The End