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Psychological Methods
Chapter 2 Psychological Methods
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Chapter 2: Section 1 Conducting Research Chapter 2
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Main Objective: List AND explain the steps scientists follow in conducting scientific research. Chapter 2
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STEPS IN SCIENTIFIC RESEARCH
Section 1: Conducting Research STEPS IN SCIENTIFIC RESEARCH Form a question (posing a question based on experience, psychological theory or common knowledge) Question: What effect does temperature have on aggressive behavior? * Construct: Cannot be seen or measured Example: aggression is experienced by everyone, but it can’t be seen or measured directly. Therefore…research questions are best directed toward behavior Behavior observed in field observations or laboratory Chapter 2
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After asking a research Question:
2. Form a hypothesis (making an educated guess). Worded in an “If” / “Then” statement. EX: If people are exposed to a hot environment then their aggressive behavior increases. 3. Test the hypothesis (examining the evidence through any of a variety of means) Chapter 2
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Section 1: Conducting Research
4. Analyze Results (looking for patterns or relationships in the evidence)…you ask what findings mean. 5. Draw a conclusion (determining whether the findings support the hypothesis and adjusting it if they do not) (known as validation) Chapter 2
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Replication: For the findings of a study to be confirmed, the study must be replicated the study must be repeated– and it must produce the same results as before. Might use a different set of participants who differ in age, gender, socio-economic background, etc. Chapter 2
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Surveys, Samples, and Populations
Section 2 Surveys, Samples, and Populations
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Survey Method Asked to respond to a series of questions about
1 Survey Method Asked to respond to a series of questions about a particular subject Gathering information by directly asking people Questionnaires Oral interviews
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Activity: Favorite Musicians
Half of the class anonymously write down your three favorite musicians Half of the class answer surveyor’s questions
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Analysis: Compare results about preferred shows between the two halves of the class. 2. Compile lists of the artists that each half claimed to like. Question…
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Analysis: Are people more willing to admit liking certain
artists if their responses are anonymous? If so, why might this be?
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Problems With Surveys? People might not be honest
2 Problems With Surveys? People might not be honest Some worry responses won’t be kept confidential and only reveal what they want to reveal Might try to please (tell questioner what they think they want to hear
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Population and Samples
3 Population and Samples What to consider when conducting research? What group or groups of people to study? How will they be selected? Example: survey on whether a vote will raise the driving age to 18
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Target Population The whole group you want to study or describe
4 Target Population The whole group you want to study or describe Example: all possible voters on a referendum Doesn’t include non-voters
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Samples Not practical to target all the voters in Pennsylvania…
5 Samples Not practical to target all the voters in Pennsylvania… instead: Researchers study a sample A cross-section as similar as possible to the target population
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Representative Sample
6 Representative Sample Example: a large number of people who represent all the voters in Pennsylvania Could then reasonably predict the outcome of the referendum by interviewing a sample this large
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Random Sample Just like it sounds; individuals are selected by chance
7 Random Sample Just like it sounds; individuals are selected by chance from the target population Each member of the target population has an equal chance of being chosen If the random sample is big enough, chances are it will accurately represent the whole population
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Stratified Sample Sub-groups are represented proportionately
8 Stratified Sample Sub-groups are represented proportionately Example: African Americans make up 12% of population so 12% of sample should be African American A large enough random sample is likely to be stratified even if you don’t take steps to make sure it is
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9 Generalizing Results Researchers are cautious about generalizing their findings to groups other than those from which their samples were drawn Example: if researchers found that men prefer certain types of cars, they couldn’t conclude that women prefer those same types of cars if women weren't included in the study
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10 Volunteer Bias People who volunteer to participate in studies may bring with them a volunteer bias Volunteers: May be more willing to disclose personal information May be more interested in research than those who don’t volunteer May have more spare time to participate in research activities than other people * All of these factors could slant the results in a particular direction
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Using Observation for Research
Section 3 Using Observation for Research
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Methods of Observation
1 Methods of Observation The Testing Method Psychologists often use tests to learn about human behavior Intelligence Aptitude Vocational Personality humanmetrics.com/cgi-win/jtypes2.asp
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2 The Case-Study Method In-depth investigation of an individual or a small group Psychologists may observe people being studied, speak directly with them, interview others who know them Genie, feral children, etc. Case of H.M. : short term and long term memory
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The Longitudinal Method
3 The Longitudinal Method Researchers select a group of participants and then observe them over a long period of time (years, even decades) Enables researchers to see how people change over time Time consuming and expensive
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Cross-Sectional Method
4 Cross-Sectional Method Researchers compare differences and similarities among people in different age groups at a given time Instead of following a set of individuals over a number of years, researchers select a sample that includes people of different ages
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Naturalistic-Observational Method
5 Naturalistic-Observational Method Researchers observe the behavior of people or animals in their natural habitats Enables researchers to witness the behavior of people or animals in their natural setting Disadvantage? No control of setting or events.
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Naturalistic-Observational Method
Determine a workable research question. Example: What is the average size of the group in which people congregate during lunch? Does it vary according to the gender of its members? Make and record your observations. Report your findings to the class.
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Laboratory-Observation Method
6 Laboratory-Observation Method Participants are observed in a laboratory setting Enables researchers to precisely control certain aspects of the study Disadvantage? Labs cant duplicate real-life environments.
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Analyzing the Observations
7 Analyzing the Observations How do psychologists analyze and interpret results? One method is correlation or the measure of how closely one thing is related to another Positive Correlation: as one goes up, the other goes up example: study time and grades(people who study more earn higher grades) Negative Correlation: as one goes up, the other goes down example: relationship between stress and health (students’ stress increases ability to fight off colds decreases) Correlation describes relationships, but doesn’t always reveal cause and effect
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Section 4 Experimental and Ethical Issues
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The Experimental Method
1 The Experimental Method Method used to answer questions about cause and effect Drawback: conditions in an experiment don’t always reflect conditions in real life video clip: Milgram Experiment
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Independent Variables
2 Independent Variables Variables: factors that can vary or change In an experiment, the independent variable is the factor that researchers manipulate so they can determine effect Example: warm temperatures cause aggression in humans
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Dependent Variables 3 dependent variable depends on something---the independent variable Example: researchers want to find out if the level of aggression depends on temperature
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Experimental and Control Groups
4 Experimental and Control Groups Ideal experiments use experimental and control groups. Members of an experimental group receive the treatment, members of a control group do not. Participants are randomly assigned to one group or another. All other conditions (except the treatment) are the same for both groups Makes it possible for researchers to conclude that the experiment’s results are caused by the treatment, not something else
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The Placebo Effect 5 A placebo is a substance or treatment that no effect apart from a person’s belief in its effect Does psychotherapy work? video clip
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Single and Double-Blind Studies
6 Q. How can researchers avoid the influence of expectations and the placebo effect? A. By keeping participants unaware of, or blind to, the treatment they are receiving. In a single-blind study, participants don’t know whether they are in the experimental group or the control group
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Double-Blind Studies 7 A study in which both participants and researchers are unaware who receives the treatment is called a double-blind study Participants assigned at random to have a real drug or a placebo Neither the people taking the medicine or the people measuring the results are aware of who’s taking what
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Central Tendency and Dispersion
8 Researchers organize data to make generalizations about that data Central tendency is a number that describes the average score of a distribution of numbers Mean, median, and mode are all measures of central tendency Standard deviation is the measure of the distance of every score To the mean (average) Large range = higher standard deviation Small range = lower standard deviation
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Ethical Issues Research with People:
9 Ethics are standards for proper and responsible behavior Research with People: Confidentiality: records of research participants are kept private Informed Consent: agree to participate only after being informed about possible negative effects and given a choice Deception: may be used only when benefits outweigh harm Ethics in Using Data: must be willing to discard their hypothesis in light of the evidence
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Ethical Issues Research with Animals
10 Research with Animals most research isn’t harmful to animals, but psychologists and scientists do sometimes carry out research that is harmful to animals video clip
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