1 / 20

CHAPTER OVERVIEW

CHAPTER OVERVIEW. All About Variables The Relationship Between Independent and Dependent Variables Other Important Types of Variables Hypotheses Samples and Populations The Concept of Significance. WHAT IS RESEARCH ALL ABOUT, ANYWAY?.

clovis
Download Presentation

CHAPTER OVERVIEW

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER OVERVIEW • All About Variables • The Relationship Between Independent and Dependent Variables • Other Important Types of Variables • Hypotheses • Samples and Populations • The Concept of Significance

  2. WHAT IS RESEARCH ALL ABOUT, ANYWAY? Increasing our understanding of how and why we behave the way we do!!

  3. THE RESEARCH PROCESS: COMING TO TERMS • From Problem to Solution • Noting an interesting question • Stating the question in such a way that it can be answered • The Language of Research

  4. VARIABLES • A class of outcomes that can take on more than one value • The more precisely a variable is measured, the more useful the measurement is

  5. DEPENDENT VARIABLES (DVs) • The Outcomes of a Research Study • Depends on the experimental treatment

  6. INDEPENDENT VARIABLES (IVs) • Treatments or conditions under control of the researcher • Levels—at least two different values of the IV must be present

  7. INDEPENDENT VARIABLES IN FACTORIAL DESIGNS

  8. THE RELATIONSHIP BETEWEEN INDEPENDENT AND DEPENDENT VARIABLES: WHAT MAKES GOOD VARIABLES? • Independent Variable is not confounded • Levels do not vary systematically with other variables • Dependent Variable is sensitive to changes in the IV

  9. OTHER IMPORTANT TYPES OF VARIABLES • Control Variable—Has a potential influence on the DV • Extraneous Variable—Has an unpredictable impact on the DV • Moderator Variable—Variables related to IVs and/or DVs, and hiding the true relationship between IVs and DVs

  10. VARIABLES—A SUMMARY

  11. HYPOTHESIS • Reflects the general problem under study • Restates the general problem in a form that is precise enough to allow testing

  12. NULL HYPOTHESIS • States that there is no relationship between the independent and dependent variables under study • Ho: µ1 = µ2 • Ho: Null hypothesis • µ1: Theoretical average of population 1 • µ2: Theoretical average of population 2

  13. PURPOSE OF NULL HYPOTHESIS • A starting point for analysis • Accepted as true absent other information • Assumes that chance caused any observed differences • Provides a benchmark for comparison

  14. H1: ≠ • H1: Research hypothesis • : Theoretical average of population 1 • : Theoretical average of population 2 X1 X2 X1 X2 THE RESEARCH HYPOTHESIS • A statement of inequality • A relationship exists between the independent and dependent variables

  15. X1 X1 X2 X1 X2 X2 DIRECTIONAL VS. NONDIRECTIONAL RESEARCH HYPOTHESES • Nondirectional Research Hypothesis • Groups are different, but direction is not specified • H1: ≠ • Directional Research Hypothesis • Groups are different, and direction is specified • H1: > • H1: <

  16. PURPOSE OF RESEARCH HYPOTHESIS • Directly tested during research process • To compare against Null hypothesis

  17. Research Inequality between variables Refers to sample Directly tested Stated using Roman symbols ( ) Explicit Null Equality between variables Refers to population Indirectly tested Stated using Greek symbols (µ) Implied X DIFFERENCES BETWEEN NULL AND RESEARCH HYPOTHESES

  18. WHAT MAKES A GOOD HYPOTHESIS? • Stated in declarative form • Posits a relationship between variables • Reflects theory or literature • Brief and to the point • Testable

  19. SAMPLES AND POPULATIONS • The SAMPLE is a representative portion of a POPULATION • The POPULATION is the entire group of interest • Results from the SAMPLE should generalize to the POPULATION

  20. SIGNIFICANCE • Observed differences (PROBABLY) result from the treatment and not from chance • Why? • Influences other than the treatment • Significance level = risk associated with not being 100% certain that Null hypothesis is incorrect

More Related