Chapter 1 Research Methods ©2011 W. W. Norton & Company, Inc. Gleitman Gross Reisberg Psychology EIGHTH EDITION

Chapter Topics Making Observations Working with Data Observational Studies Establishing Cause and Effect: The Power of Experiments Research Ethics

Chapter Topics The Power of Science Some Final Thoughts: Methodological Eclecticism Summary

Research Methods Psychological claims are about facts, and to check on these empirical claims, psychologists rely on the methods of science.

Making Observations Scientific observations begin with a question or hypothesis. The hypothesis must be testable. This calls for an operational definition of key terms to specify the study’s dependent variable. Data must also be systematically collected. Researchers ignore anecdotal evidence.

What Observations can be Made Here?

Define the Variables A variable is any characteristic you want to measure or count. This can be numbers, data item, quantity, or characteristic. Age, gender, eye color, etc., are all variables. Independent variables are predictor variables. They are somehow manipulated. Dependent variables are outcome variables. You observe the predictor’s effects on the outcomes.

Testable Hypothesis A prediction that has been formulated specifically enough so that it is clear what observations would confirm the prediction and what observations would challenge it. It is a specific claim about the facts that is framed in a way that will allow a clear test. This includes the assumption that the hypothesis is false.

Lets look at some brief research…   What are the potential hypotheses in this video?  What are the variables?

Two Main Types of Research  Quantitative: Research that seeks to explain and make sense of things in your world by collecting numerical data that is analyzed using mathematics, usually statistics. Data is gathered objectively. When analyzed this data is used to make predictions or suggest relationships between and within variables.

Qualitative Research  Second main type of research. Qualitative research is designed to reveal a target audience’s range of behaviors and the perceptions that drive these actions. It uses in depth studies of small groups to guide and support the hypotheses. Qualitative research seeks to describe rather than predict. Researchers immerse themselves into what they are studying yo understand it better.

Collecting Your Data This must be done carefully and in a way that protects what you are trying to measure. It is as objective as possible. Start with defining your sample. What was the exact sample in the video?

Defining the Sample Based on observations of a sample, psychologists want to draw conclusions about a broad population. Random sampling All members of the population have an equal chance of being picked to participate. Researchers also use other procedures, including case studies. A case study is where one issue (even a group) is studied

Confounding Variables These are the extra variables. They are in your sample. These are variables that you may not have the time or the money to factor in. They influence the outcomes but they are not being measured.

What are the potential confounding variables here?   What are the potential variables, that are not being measured or considered, in this experiment?

Validity  External: Can the outcomes from the research be generalized to other samples or populations?  Internal: Does the research measure what it states it will measure? Do the variables show cause and effect? Is the relationship between the variables clearly shown?

Assessing External Validity Researchers want their study to mirror circumstances of the broader world. external validity External validity depends on many factors. The study should not change behaviors the researchers hope to understand. The sample should be reflective of the population we are studying. Depends on what you are studying.

Assessing External Validity One concern here involves the study’s possible demand characteristics: cues that can signal to participants how they’re supposed to behave One way of avoiding this problem is to use a double-blind design. This is where neither the data collector nor the participant know the hypotheses.

Validity   Discussion.

Reliability  In order to be valid, the research must first be considered reliable.  To show reliability in research the variables must be stable or constant.  This means if the study is replicated, the variables, and the ways they are measured, should look the same as they did in the first study.

Reliability  Consistency, or this variable stability, should be seen across similar studies, when there different raters, across the tests and measures used, etc.  Types include inter-rater, internal consistency, test-retest, and parallel forms.

Reliability   Discussion.

Working with Data Researchers use descriptive statistics to summarize the data from their studies. This data describes what is happening. These include: measures of the data’s central tendency. often computed as a mean measures of the variability. often assessed by standard deviation

Frequency Distribution Shows you how the scores vary in frequency. Mean (average) and median (value that is half way). Standard Deviation shows how far each data point is away from the mean.

Correlations Researchers use correlations to summarize the pattern of data. Are changes in one measurement linked to changes in another measurement? correlation coefficient, r Correlations can be used to: check on reliability of measurements. assess each measure’s validity. Assess for possible links. Correlation is not cause and effect.

Inferential Statistics Researchers use inferential statistics to make inferences based on their data. This involves testing a difference between two groups. provides an assessment of a result’s statistical significance expressed as a p-value, indicating the probability of getting the data pattern by chance

Observational Studies Observational studies are crucial for psychology, but they’re often uninformative about causation. We can’t be sure which observation is the cause and which is the effect. Also, there’s the third-variable problem: Some other (i.e., third) variable is influencing both variables observed in our study.

Cause and Effect Assessing cause and effect requires experiments that change some aspect of a situation and show the results. Must treat experimental group and control group exactly the same except for the experimental manipulation.

The Power of Experiments The two groups must be matched at the outset of the experiment. To ensure matching groups, researchers use: random assignment. within-subject comparison. taking precautions to address problems created by the sequence of conditions

The Power of Experiments Scientific conclusions rarely rest on a single experiment. To confirm or disconfirm the hypothesis, the experiment must be: scrutinized by other researchers. replicated through subsequent studies.

Research Ethics Researchers must take precautions to protect the study participants’: physical well-being. privacy. autonomy. dignity.

Research Ethics If ethical requirements conflict with procedures needed to ensure a study’s validity, then all risks to the participants must be minimized. Any remaining risks must be fully justified on scientific grounds.

The Power of Science Methods of science can also be used to evaluate claims in everyday life. People can apply these methods to help ensure their conclusions are warranted. Politicians can make certain their policies are in line with the best available evidence.

Thursday  In Class assignment.

Concept Quiz 1)A modern definition of psychology is: a)the exploration of human nature. b)the scientific study of behavior and mental processes. c)the treatment of abnormal behavior and mental illness. d)the systematic study of individual differences.

Concept Quiz 2)Which element of experimental design reduces the chances that participants assigned to an experimental group will differ in some unintended but meaningful way from participants assigned to the control group? a)internal validity b)double-blind design c)random assignment d)between-subject comparisons

Concept Quiz 3)Research ethics requires that after an experiment, researchers explain the study to participants. This procedure is known as: a)informed consent. b)debriefing. c)reverse psychology. d)risk management.

Video Clips

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