1. Research Methods
Chapter 2

2. How Do Psychologists Develop New Knowledge?
Psychologists, like researchers in all other sciences, use the scientific method to test their ideas empirically.

3. How Do Psychologists Develop New Knowledge?
Empirical investigation – “experienced based” An approach to research that relies on sensory experience and observation as research data.
Scientific method – A five-step process for empirical investigation of a hypothesis under conditions designed to control biases and subjective judgments.

4. We call these explanations, THEORIES!
A main goal of psychological science is to develop scientific explanations for behavior and mental processes.
We call these explanations, THEORIES!
To scientists theory means the power to explain the facts and its ability to be tested objectively.

5. The Five Steps of the Scientific Method
Developing a hypothesis
Performing a controlled test
Gathering objective data
Analyzing the results
Publishing, criticizing, and replicating the results

6. Developing a hypothesis
Hypothesis – A statement predicting the outcome of a scientific study
Operational definitions – Exact procedures used in establishing experimental conditions and measurement of results

7. Performing a controlled test
Independent variable – The variable manipulated by the experimenter
Random presentation –
Using chance alone to determine the order in which the stimulus is presented

8. Gathering objective data
Data – Information gathered by researcher and used to test a hypothesis
Dependent variable – The measured outcome of a study; the responses of participants in a study

9. Analyzing the results
Based on statistical analyses of results, the hypothesis is accepted or rejected

10. Publishing, criticizing, and replicating the results
Researchers must find out whether their work can withstand the scrutiny of the scientific community.
How is this done?

11. Psychological Research
What are confounding and extraneous variables? How do they effect the scientific method?
What is “random assignment” and how is it used in experiments?

12. Non-Experimental Methods
There are some situations in which experiments cannot be done for ethical reasons.
Non-Experimental methods can yield useful data, but they are just not “true” experiments because they are missing a component of the experiment, usually in the areas of the controls.
Ex Post Facto: subjects are chosen on the basis of a preexisting condition. Example?

13. Types of Psychological Research
In experiments, the researcher controls all the conditions and directly manipulates the conditions
Non-experimental methods include:
Correlational studies
Surveys
Naturalistic observation
Longitudinal studies
Cross-sectional studies
Cohort-sequential studies

14. Correlation Studies
Are used to see a relationship (correlation) btw two variables.
Smoking and lung cancer.
CORRELATION DOES NOT NECESSARILY MEAN CAUSATION!

15. Continued…
The degree of correlation is normally expressed as a number. R= correlation coefficient
Range from negative # (-1.0: + 1.0)
If variables have no relationship= zero correlation
Relationship in which they vary in the same direction = positive correlation (+0.4)
A correlation can show a strong relationship even when its negative.

16. Surveys
Not a true experiment, but if conducted correctly can yield useful data.
Researchers need to make sure the questions are not skewed or bias.
Participants tend to not take surveys seriously, due to this surveys tend to yield incorrect results.

17. Naturalistic Observation
Subjects are observed in their natural environment.
Subjects should NOT know they are being observed, this way the behavior being observed is actual behavior in their natural state.
Children on the playground, animals in the wild.

18. Longitudinal Studies
One group of subjects is followed/observed for an extended period of time.
Benefits: same subject group
Negatives: Time and expense
Example: Following special needs children for their first 15 years of their lives.

19. Cross-Sectional Studies
Examines a representative cross section of the population and tests/surveys these subjects at one specific time.
Will yield data similar to longitudinal studies, but the data won’t be as accurate.

20. Cohort-Sequential Studies
Similar to Cross-Sectional
Here, researchers take a cross section of the population and then follows each cohort or group for a short period of time.
This study takes less time than longitudinal studies and yields more accurate data than a cross sectional study.

21. Sources of Bias
Bias could affect the way an experimenter designs a study, collects data, or interprets results
Sources of bias include:
Personal bias
Expectancy bias

22. Personal Bias
Involves and individuals beliefs, preferences, assumptions, or prejudices.
This bias can cause scientists to notice only evidence confirming their hypotheses and to ignore contrary data

23. Expectancy Bias
This bias effects observations when observers expect and LOOK for certain outcomes.
Bias not only leads to erroneous conclusions, but it can also be expensive.

24. How to “control” a Bias Double blind studies attempt to control bias.
This strategy ensures that the experimenters will not inadvertently treat the experimental group differently from the control group, so that neither group will have any idea about the expected response.
Placebo:
Researchers must also attempt to control confounding variables

25. Ethics in Research
In order to make sure research is conducted in an appropriate manner, guidelines are put in place by the APA, IRB, and IACUC.
These boards review and approve all research and make sure the experiments comply with local, state, national requirements.
Deception
Debriefing
Animal research

26. Deception
Participants should be advised about what challenges they will face and give them an opportunity to drop out.
In other situations, participations must be informed of deception as soon as possible with out compromising the study's research goals.
They must be debriefed to make sure there is not lasting ill effects.

27. Animal Studies
Psychologists, most support the use of animal research. But, they do not support or approve of animal studies that cause harm, pain, or result in death of their subjects.

28. Questions Science Cannot Answer
The scientific method is not appropriate for answering questions that cannot be put to an objective, empirical test
Ethics
Morality
Religious beliefs
Preferences

29. How Do We Make Sense of the Data?
Researchers use statistics for two major purposes: (1) descriptively to characterize measurements made on groups or individuals and (2) inferentially to judge whether these measurements are the result of chance