1. Quantitative and Qualitative Research

2. Theory vs. Hypothesis From last class… Good research is informed by theory, or “a unified explanation for discrete observations that might otherwise be viewed as unrelated”  From theory, researchers deduce testable hypotheses Deduction: general to specific  From observations, researchers can induce theory Induction: specific to general A hypothesis is a specific statement predicting some outcome of an experiment or connection between variables

4. Scientific Method 1. Formulate theories √ 2. Develop testable hypotheses √ 3. Conduct research, gather data 4. Evaluate hypotheses based on data 5. Cautiously draw conclusions

5. Two major approaches to conducting research Quantitative  Deductive (general to specific) Have theory, want to gather observations or evidence to test it  Hypothesis-testing Qualitative  Inductive (specific to general) Have interesting observations or evidence, want to build a theory to explain them  Hypothesis-generating

6. Two major approaches (cont.)  Quantitative: Measuring quantities of behaviors or responses - matter of degree Information (data) that can be expressed in numerical terms, counted, or compared on a scale Seeks numbers or data that can convert to numbers  Qualitative: Assessing the nature, quality, or themes of behavior or responses – matter of kind Information (data) that is categorical or descriptive, rather than numerical Seeks descriptions, or data in words

7. Examples of two major approaches Quantitative  Self-report (e.g., surveys, interviews)  Observational  Performance Qualitative  Self-report (e.g., surveys, interviews)  Observational  Case study  Ethnography  Content or narrative analysis  Grounded theory

8. Questions for discussion 1.Which kind of data is more convincing to you, numbers or words? Imagine you had to make an important decision about patient treatment or a therapeutic intervention. 2. Why do you think the history of psychology has been dominated by the quantitative approach? 3. Which fields are more likely than psychology to have incorporated qualitative approaches?

9. Choosing participants for two major approaches The way in which a researcher selects people to participate in their study is called sampling Quantitative sampling  More often use random sampling, in which all people in population have same odds of being selected to participate Generally not open to change once study has begun Qualitative sampling  More likely to use purposive sampling, in which key informants are sought to participate Participants may change during study

10. Marshall (1996) article Both quantitative and qualitative researchers do not give enough attention to sampling Major question: Why shouldn’t both approaches use the same sampling methods? Quantitative seeks to generalize result to whole population so random or representative sampling is used  Sometimes quota or convenience Breadth Qualitative seeks to gather gather result that offer insights on a small group so purposive or judgment sampling is used  Sometimes convenience or theoretical Depth

11. Final notes on both approaches Both approaches begin with literature reviews; quantitative more likely to replicate designs or previous research, qualitative more likely to use research to establish gaps The approaches can be used in a complementary fashion, together providing a fuller understanding of phenomena  “Mixed methods” or “multi-method” approach Quantitative approach may be preferred if time and money are limited Quantitative approach may be preferred if audience seeks concise answer to their question Qualitative approach may be preferred if research is delving into brand new area or new field Qualitative approach may be more respectful to some cultures or to unknown populations