How to identify Variables and Write Research Hypotheses
- 2. Variables are a class of outcomes that can take on more than one value. Eg. include: Height, Weight, Social class, Color Variables can therefore be further divided into specific categories or attributes Eg. Social Class: Underclass Lower Class, Working Class, Middle Class, Upper Class The more precisely a variable is measured, the more useful the measurement is
- 7. Independent Dependent Represents the treatments or conditions that the researcher has either direct or indirect control over to test their effects on a particular outcome. At least two different values of the independent variable must be present reflects the outcomes of a research study.
- 8. The longer you spend on a task the better the results. People who attend church regularly are more likely to oppose abortion Educated women are likely to have fewer children
- 9. Type of Variable Definition Other Terms You Might See Dependent A variable that is measured to see whether the treatment or manipulation of the independent variable had an effect • Outcome variable • Results variable • Criterion variable Independent A variable that is manipulated to examine its impact on a dependent variable • Treatment • Factor • Predictor variable Control A variable that is related to the dependent variable, the influence of which needs to be removed • Restricting variable Extraneous A variable that is related to the dependent variable or independent variable that is not part of the experiment • Threatening variable Moderator A variable that is related to the dependent variable or independent variable and has an impact on the dependent variable • Interacting variable
- 11. Reflects the general problem under study Restates the general problem in a form that is precise enough to allow testing Two types: ❑ Null Hypothesis ❑ Research Hypothesis
- 12. States that there is no relationship between the independent and dependent variables under study : Ho = the symbol for the null hypothesis ❑ There will be no difference in the average score of ninth graders and the average score of twelfth graders on the ABC memory test. ❑ There is no relationship between personality type and job success. ❑ There is no difference in voting patterns as a function of political party.
- 13. A starting point for analysis Accepted as true absent other information Assumes that chance caused any observed differences Provides a benchmark for comparison
- 14. Whereas a null hypothesis is a statement of no relationship between variables, a research hypothesis is a definite statement of the relationship between two variables. Nondirectional Research Hypothesis Groups are different, but direction is not specified Teachers who are more knowledgeable about HIV/AIDS treat their students differently than those who do not know as much. Directional Research Hypothesis Groups are different, and direction is specified Teachers who are more knowledgeable about HIV/AIDS treat their students who are infected better than those who do not know as much.
- 15. Is stated in declarative form Posits a relationship between variables Reflects theory or literature Is brief and to the point Is testable