1. CHAPTER 4 – RESEARCH METHODS Psychology 110

2. How Do We Know What We Know? You can know something because a friend told you You can know something because you read it You can know something because it “seems obvious” (i.e. common sense) You can know something because it “feels right” (i.e. intuition) These ways of knowing may be right, but they may also be wrong. Psychologists rely on the scientific method because it is more likely to answer certain kinds of questions correctly.

3. The Scientific Method A method of learning about the world through observation, experimentation and statistical analysis

4. Observation & Bias Simplest scientific method Potential for bias Most common bias = “confirmation bias,” a tendency to search for information that confirms a preconception. Participant bias = tendency for research participants to behave in a certain way because they know that they are being observed or they believe they know what the researcher wants You can minimize these biases through naturalistic observation = observing/recording behavior without manipulating or controlling the situation

5. Case Study A specific research technique that relies on observation Study a single individual in depth in the hope of revealing universal principles May or may not be possible to extend the findings to other people or situations Researchers hope that they can gain important knowledge from case studies that can help explain general truths about human behavior As similar case studies accumulate, researchers gain increasing confidence in the accuracy of their conclusions

6. Example Case Study - Genie Discovered in California in 1970 13 years old Had spent her life in such isolation that she had not even learned to speak Since 1970 psychologists have intensively studied Genie’s behavior and progress to learn about the development of language and social skills ***this would be considered a longitudinal case study

7. 4. Correlations Is there a relationship between two variables? Positive correlation – both variables increase (or decrease together).  People with higher income have more years education Negative correlation – one variable increases while the other decreases.  The more that babies are held the less that they cry. Does not reveal a cause-and-effect relationship, just that there is a relationship between the two variables. Useful for making predictions.

8. 5. Surveys Questions a sample of people to collect information about their attitudes or behaviors Inexpensive Bias can influence the wording of a question and thus the results Population = the entire group of people about which you would like to know something (Leo Hayes students) Random sample = a sample that fairly represents the “population” In general, larger, random (computer) samples are “better”

9. 2. Experiments Only way to show cause-and-effect A research method in which the researcher manipulates and controls certain variables to observe the effect on the other variable Because experiments require researchers to control the variables in a study, the chances of isolating the variable causing the particular effect are much greater

10. Continued – Hypothesis & Operational Definitions Hypothesis = a testable prediction about the outcomes of research Often starts out general but then gets more specific Operational Definitions = attempt by researchers to clearly define the behaviors that they are looking for

11. Continued - Variables Independent Variables (IV):  The variable that should cause something to happen  The variable that the researcher manipulates  The variable that will cause a change in the dependent variable Dependent Variable (DV):  The variable that should show the effect of changing the IV  The IV causes the DV to happen

12. Continued - Groups Typically experiments have two groups – experimental and control Experimental – exposed to the independent variable Control – not exposed to the independent variable (function as a comparison group) Usually at least 20 people in each group Should be randomly chosen to avoid bias

13. Continued – Confounding Variables “Other” variables (than the IV) that could affect the dependent variable Environmental, expectations Environmental – same temperature, lighting, noise Expectations – make sure that participants are not aware of hypothesis (could alter their behavior)

14. Continued - Replication Researchers should be able to replicate your exact experiment

15. New – Research Ethics See handout