1. Chapter 2: Psychological Methods
How do we conduct scientific research?
How is the data interpreted?
Are results of a study valid?

2. Section 1: Conducting Research
Psychology is an experimental science (assumptions must be supported by evidence)
Scientist must be skeptical and doubt claims
5 steps to conducting research
Forming a research question
Forming a hypothesis
Testing the hypothesis
Analyzing results
Drawing conclusions

3. Forming a research question
Research questions arise from:
Daily experiences
Psychological theory
Folklore or common knowledge

4. Forming a Hypothesis
A hypothesis is an educated guess which can be tested
A hypothesis can be tested on:
An assumption
Personal experience
Observation

5. Testing the hypothesis
A hypothesis cannot be considered correct until it has been scientifically tested and proved right
Psychologist do no rely on people’s opinions. They examine evidence and draw their own conclusions
There are many methods to test a hypothesis

6. Analyzing Results
After psychologists have tested their hypotheses, they analyze their results (they ask what their findings mean)
It may take weeks, months, or even years to collect data
When more data is collected, it becomes more complex to analyze it
Psychologists look for patterns and relationships in the data
They must decide which data supports their hypothesis and which data does not

7. Drawing conclusions
After research has been analyzed, conclusions can be drawn about the initial question and hypotheses
When observations or data does not support a Hypothesis, theories and beliefs from which the hypothesis was derived must be changed
Psychologist must be willing to adjust or modify their hypotheses if their findings make it necessary to do so

8. Replication
For findings to be confirmed, they must be replicated (repeated with the same results)
Sometimes scientists repeat a study under different circumstances
Example: A different set of participants
Gender, Age, Ethnicity, Social & Economic Backgrounds, education, geographic setting, etc.

9. New Questions
Findings of a research study are likely to lead to new research questions
Once new questions have been asked, the process begins all over again

10. Section 2: Surveys, Samples, and Populations
One way to gather information is to ask people directly

11. Survey Method
In a survey, people are asked to respond to a series of questions about a particular subject
Types of Surveys
Written questionnaire
Oral interview
Not always accurate
Not always honest
Afraid of confidentiality
May try to please interviewer

12. Population and Samples
Researchers consider what group or groups of people they wish to examine
How will respondents be selected
A target population is the whole group which will be studied
A sample is only part of the target population

13. Selecting Samples
Samples are selected scientifically
Samples should be good representations of their populations (Samples should be similar as possible to the target Population, otherwise, researchers will be unable to use the sample to make accurate predictions about the population)
2 types
Random sample—individuals are selected by chance
All members of population have an equal chance of being selected
Stratified Sample—subgroups of the population are represented proportionally
Large random samples are likely to be stratified
people will usually represent the general American population reasonably well

14. Generalizing Results
Sometimes researchers do not use a sample that represents an entire population, the researcher wants to know about only one group within the population and thus has no reason to study the other groups
Researchers are cautious about generalizing their findings to groups other than those from which their samples were drawn
Researchers cannot learn about the preferences of all people by studying only one group of people

15. Volunteer Bias
Researchers often have little control over who responds to surveys or participates in research studies
Volunteer bias—People who volunteer to participate in a study often differ from those who do not
Volunteers are usually :
More willing to disclose personal information
More interested in the research
May have more time to participate in studies
These factors skew the results

16. Section 3: Methods of Observation
When we make observations, we tend to make generalizations, however, most of our observations are fleeting and haphazard. We often ignore the obvious and cannot draw scientific conclusions based only on our unstructured observations.
Personal observations can serve as a starting point for a psychologist’s hypothesis
7 Methods of observation:
Survey
Testing
Case-Study
Longitudal
Cross-Sectional
Naturalistic-Observation
Laboratory-Observation

17. Testing Method Psychological test help us learn about human behavior
Intelligence tests—measure general learning ability
Aptitude tests—measure specific ability & special talents
Personality tests—measure character traits
Other—vocational interests

18. Case-Study Method
A case-study is an in-depth investigation of an individual or small group
Uses:
Observation
Interview (subjects & people who know the Subject)
Learn about their backgrounds and Personal Histories
Try to generalize the broader principles to the larger population
Sigmund Freud (psychoanalysis)—mostly based on case studies
Pitfalls are People’s recollections are filled with gaps in inaccuracies:
People do not remember details
People distort their past to impress others

19. Longitudial & Cross- Sectional Methods
Cross-Sectional studies how people and organisms change over time
Instead of following a set of individuals, researchers select individuals that include people of different ages, then compare the behaviors of the different age groups
Example: Have 12 different age groups
Less reliable than longitudal
Changes in behavior from one group to the next may be due to circumstance, environment or experience
Longitudal studies how people or organisms change over time (sometimes years or even decades)
Select group of individuals
Observations usually conducted at intervals
Example: once per year for 12 years
Researchers must have a lot of patience

20. Naturalistic-Observation Method
Observing people in their natural habitat
Sometimes called “field study”
Researchers do not interfere with the organism they are observing, they simple observe

21. Laboratory-observation method
Sometimes it is more useful to study in a laboratory rather than the field. This is called Laboratory-observation
The laboratory is a suitable environment in which the research can be conducted
Sometimes the researcher can manipulate the environment to control the environment of the study
B.F. Skinner was famous for using special enclosed environments for his studies called skinner boxes

22. Analyzing Observations
Researchers are looking for correlations, how closely one thing is tied to another
Positive correlation—as one thing goes up, so does the other
Negative correlation—as one thing goes up, the other goes down

23. Section 4: The Experimental Method
The method researchers use to answer questions about cause and effect is the experiment
In an experiment, participants receive a treatment. Researchers study how treatment influences behavior
Limitations—conditions created in an experiment may not reflect conditions in real life

24. Independent and Dependent Variables
Variables are factors that can vary, or Change
Independent Variable—the factor that researchers manipulate so that they can determine its effect
Dependent Variable—depends on the independent variable

25. Experimental and Control Groups
When an experiment uses control groups and experimental groups, it is called a controlled experiment
Experimental Groups receive the treatment
Control Groups do not receive treatment
All other conditions are held constant for both groups

26. Placebo Effect Our expectations affect what happens to us
A placebo is a substance that has no effect other than the persons belief in it.

27. Single-Blind Study
A blind study occurs when participants are blind to the treatment they are receiving. (in other words, they do not know if they are receiving treatment or placebo)
Experimental group-receives treatment
Control group-receives placebo

28. Effect of treatment in a Single-Blind study
What does it mean if the people taking the new drug improve faster, regardless of what they have been told, but people who take the placebo do not?
It means the drug is effective!
What does it mean if all the people who are told they are taking the drug get better faster, whether they are taking the drug or the placebo?
It means that they improve because of their expectations—because of a belief that they are taking a helpful drug—and not because of the effects of the drug itself.

29. Double-Blind Study Researchers themselves also have expectations
In a double-blind study, people observing the participants are also unaware of who is taking the treatment and who is taking the placebo
So, both experimenters and participants are unaware of who is the controlled group and who is the experimental group. This will ensure that researchers remain unbias.
Double-Blind studies are required by the FDA before any new drugs can be put on the market

30. Section 5: Ethical Issues