Psychological Research

Psychological Research Chapter 2 Pgs. 34-54

Pre-Research Decisions • Must begin with a specific question about a limited topic or hypothesis. • Sample: a relatively small group out of the total population under study. • A sample must be representative of the population a researcher is studying. • Two ways to avoid a non-representative sampling: random or stratified.

Samples • Random: each individual has an equal chance to be chosen for the experiment. • Stratified: subgroups in the population are represented proportionately in the sample

Methods of Research • Researchers use three methods • survey • case study • experiment • each method provides a different kind of information

Surveys • Survey • way to obtain information by asking many individuals • answer a fixed set of questions about particular subjects • Disadvantages • information can contain errors • results can be biased • Advantage • efficient way to obtain a lot of information from a large number of people

Case Study • Case study • an in-depth analysis of the thoughts, feelings, beliefs, experiences, behaviors, or problems of a single individual • Disadvantage • detailed information about a particular person may not apply to others • Advantage • detailed information allows greater understanding of a particular person’s life

Experiment • Experiment • a method for identifying cause-and-effect relationships by following a set of rules and guidelines that minimize the possibility of error, bias, and chance occurrences. • Disadvantage • information obtained in one experimental situation or laboratory setting may not apply to other situations • Advantage • has the greatest potential for identifying cause-and-effect relationships with less error and bias than either surveys or case studies

Decisions About Doing Research • What is the best technique for answering a question? • Questionnaires and interviews • Laboratory experiments • Standardized tests • Animal models

Research (cont.) • Interview • technique for obtaining information by asking questions, ranging from open-ended to highly structured, about a subject’s behaviors and attitudes, usually in a one-on-one situation • Questionnaire • technique for obtaining information by asking subjects to read a list of written questions and check off specific answers • Laboratory experiments • techniques to gather information about the brain, genes, or behavior with the lease error and bias by using a controlled environment that allows careful observation and measurement • Standardized tests • technique to obtain information by administering a psychological test that has been given to hundreds of people and shown to reliably measure thought patterns, personality traits, emotions, or behaviors • Animal Models • involves examining or manipulating some behavioral, genetic, or physiological factor that closely approximates some human problem, disease, or condition

Research (cont.) • Choosing research settings • Naturalistic setting • Laboratory setting • Naturalistic setting • relatively normal environment in which researchers gather information by observing individuals’ behaviors without attempting to change or control the situation • Laboratory setting • involves studying individuals under systematic and controlled conditions, with many of the real-world influences eliminated

Types of Studies • Longitudinal Studies: follow the same group of people through the years, measuring them from time to time. • Disadvantages: time-consuming and precarious: participants may disappear in mid-study. • Advantages: Ideal way to examine consistencies and inconsistencies in behavior over time.

Types of Studies (cont.) • Cross-Sectional Study: organize individuals into groups on the basis of age. Then, these groups are randonly sampled, and the members of each group are surveyed, tested, or observed simultaneously. • Advantages: less expensive and reduce the amount of time necessary for the studies.

Correlations • Correlation: Describe how two sets of data relate to each other. • Disadvantage • information obtained in one experimental situation or laboratory setting may not apply to other situations • Advantage • has the greatest potential for identifying cause-and-effect relationships with less error and bias than either surveys or case studies

Correlations (cont.) • Perfect positive correlation coefficient • +1.00 means that an increase in one event is always matched by an equal increase in a second event • Positive correlation coefficient • indicates that as one event tends to increase, the second event tends to, but does not always, increase • increases from +0.01 to +0.99 indicate a strengthening of the relationship between the occurrence of two events • Zero correlation • indicates that there is no relationship between the occurrence of one event and the occurrence of a second event

Correlation (cont.) • Negative correlation coefficient • indicates that as one event tends to increase, the second event tends to, but does not always, decrease • -0.01 to -0.99 indicates a strengthening in the relationship of one event increasing and the other decreasing • Perfect negative correlation coefficient • -1.00 means that an increase in one event is always matched by an equal decrease in a second event • correlations such as –1.00 are virtually never found in applied psychological research

Scientific Method: Experiment • Advantages of scientific method • scientific Method • approach of gathering information and answering questions so that errors and biases are minimized • Conducting and Experiment: seven rules • Rule 1: Ask • Rule 2: Identify • Rule 3: Choose • Rule 4: Assign • Rule 5: Manipulate • Rule 6: Measure • Rule 7: Analyze

Scientific Method (cont.) • Rule 1: Ask • hypothesis • educated guess about some phenomenon stated in precise, concrete language to rule out any confusion or error in the meaning of its terms • Rule 2: Identify • independent variable • a treatment or something that the researcher controls or manipulates • dependent variable • one or more of the subjects’ behaviors that are used to measure the potential effects of the treatment or independent variable

Scientific Method (cont.) • Rule 3: Choose • random selection • each participant in a sample population has an equal chance of being selected for the experiment • Rule 4: Assign • experimental group • those who receive the treatment (experimental group) • participants who undergo all the same procedures as the experimental participants except that the control participants do not receive the treatment (control group) • Rule 5: Manipulate • double blind procedure • neither participants nor researchers know which group is receiving which treatment

Scientific Method (cont.) • Rule 6: Measure • by manipulating the treatment so that the experimental group receives a different treatment than the control group, researchers are able to measure how the independent variable (treatment) affects those behaviors that have been selected as the dependent variables • Rule 7: Analyze • statistical procedures • used to determine whether differences observed in dependent variables (behaviors) are due to independent variables (treatment) or to error or chance occurrence Look at figure 2.2 in textbook on page 40 for example

Descriptive Statistics: The listing and summarizing of data in a practical and efficient way. Frequency distribution How often something occurs Measures of central tendency A number that describes something about the “average score” Measures of variance An index of how spread out the scores of a distribution are Correlation coefficients Describes the direction and strength of the relationship between two sets of observations. Inferential Statistics: Methods that can be used to determine whether data supports a hypothesis or were to chance. Probability and chance statistical significance less than five percent chance results are not due to chance Statistical Evaluation

Problem: Self Fulfilling Prophecy: having expectations about a behavior and then acting in some way, usually unknowingly, to carry out that behavior. Experimenters may tip subjects off (raising eyebrow, shaking head, frowning). Clever Hans Experiment. (page 46) Solution: Single blind experiment: participants are unaware which group has received treatment. Double blind experiment: neither participants nor experimenter(s) know which group received treatment. Problems and Solutions in Research

Problem: Placebo Effect: A change in a patient’s illness or physical state that results solely from the patient’s knowledge and perceptions of the treatment. Recently, it has even been shown that "mock" surgery can have similar effects, and so some surgical techniques must be studied with placebo controls. The opposite effect, in which a patient who disbelieves in a treatment receives less benefit, is known as the nocebo effect. Solution: Sometimes a doctor's belief in the value of a treatment can affect his behavior, and thus what his or her patient believes, such trials are usually conducted in "double blind” fashion. Problems and Solutions in Research (cont.)

Ethical Issues • Code of ethics • the American Psychological Association publishes a code of ethics and conduct for psychologists to follow when doing research, counseling, teaching, and related activities • Plan research so as to minimize the possibility of misleading results. • Psychologists are responsible for the dignity and welfare of participants. • Obey all state and federal laws, as well as professional standards. • With some exceptions, reach an agreement regarding the rights and responsibilities of researchers and participants. • Obtain a signed, informed consent before starting any research with a participant. • Deception should be used if only no better alternative is available

Ethics in Experimentation • 1. Subjects have the right to participation or withdraw at any time • 2. Openness and honesty are essential to experimentation • 3. Information must remain confidential. • 4. The experimenter must assess carefully the possibility of potential risks, inform participants, and remove any undesirable consequences of participation. • Little Albert • Read about the experiment performed on Little Albert by John Watson on pp. 249. Which of the above ethical principles did John Watson violate? How?

Psychological Research