Chapter 4 Research Methods Flashcards
Hypothesis
an educated guess, about what you expect to find
Research design
includes the aspects you want to measure in the people you are studying (dependent variable) and the influences on their behaviors (independent variable)
Internal validity
- you can be confident that the independent variable is causing the dependent variable to change
- the extent to which we can be confident that the independent variable is causing the dependent variable to change
External validity
- how well the results relate to things outside your study- how well your findings describe similar individuals who were not among the study participants
- refers to how well the results relate to things outside your study; in other words, how well your findings describe similar individuals outside the laboratory
Testability
- the ability to support the hypothesis
- Ability of a hypothesis, for example, to be subjected to scientific scrutiny and to be accepted or rejected, a necessary condition for the hypothesis to be useful.treatment outcome research,
Social psychology
- heightened motivation to make sense of the world, especially if we experience situations that seem to threaten our sense of order and meaning
- People who do not seem to want to know why others behave the way they do- psychological disorder
Confound (confounding variable)
- any factor occurring in a study that makes the results uninterpretable because a variable other than the independent variable (MDMA use) may also affect the dependent variable (scores on cognitive abilities)
- Internal validity - Anything that affects a dependent variable and may unintentionally vary between the experimental conditions of a study.
Control group
- people are similar to the experimental group in every way except that members of the experimental group are exposed to the independent variable and those in the control group are not.
- Help rule out alternative explanations for results, thereby stregthening internal validity
- In an experiment, the group that is not exposed to the treatment; contrasts with the experimental group and serves as a comparison for evaluating the effect of the treatment.
Randomization
- process of assigning people to different groups in such a way that each person has an equal chance of being placed in any group
- Randomly place people in groups but still end up with more of certain people in one group than another
- Placing people in groups by flipping a coin or using a random number table helps improve internal validity by eliminating any systematic bias in assignment, but it does not necessarily eliminate bias in your group
- Self-selection can affect study results
- The most severely depressed individuals may not be motivated to come to frequent treatment sessions and so will choose the wait-list group
Analogue models
- create in the controlled conditions of the laboratory aspects that are comparable (analogous) to the phenomenon under study
- If they used volunteers of any age, gender, race, or background, the researchers could rule out influences on the participants’ attitudes about eating that they might not be able to dismiss if the group contained only people with bulimia.
- Such “artificial” studies help improve internal validity
Generalizability
- results apply to everyone with a particular disorder
2. the extent to which results apply to everyone with a particular disorder.
Statistical significance
a mathematical calculation about the difference between groups
Clinical significance
- whether or not the difference was meaningful for those affected
- Few of us, would say staying sober for 2 extra days was worth taking medication and participating in extensive therapy- the difference may not be clinically significant
Effect size
Concern for the clinical significance of results has led researchers to develop statistical methods that address not just that groups are difficult but also how large these differences are: effect size
Patient uniformity myth.
- Kiesler (1966) labeled the tendency to see all participants as one homogeneous group the patient uniformity myth.
- Comparing groups according to their mean scores hides important differences in individual reactions to our interventions
- Leads researchers to make inaccurate generalizations about disorders and their treatments
Case study method
- investigating intensively one or more individuals who display the behavioral and physical patterns
- Begin exploring a relatively unknown disorder
- Noting what it is not
- It does not use the scientific method
- Few efforts are made to ensure internal validity
- Many confounding variables are present that can interfere with conclusions
- Relies on a clinician’s observations of differences among one person or one group with a disorder, people with other disorders, and people with no psychological disorders
- Collects as much information as possible to obtain a detailed description of the person
- Yields a great deal of information on personal and family background, education, health, and work history, as well as the person’s opinions about the nature and causes of the problems being studied
- Important in the history of psychology
- Sigmund Freud: psychoanalysis theory and psychoanalysis -> basis of his observations of dozens of cases
- Freud and Josef Breuer’s description of Anna O: free association
- Virginia Johnson and WIlliam Masters: based their work on many case studies
- Joseph Wolpe: based his work with systematic desensitization on more than 200 cases
- As our knowledge of psychological disorders has grown, psychological researcher’s reliance on the case study method has gradually decreased
- Sometimes concidences occur that are irrelevant to the condition under study -> often lead to mistaken conclusions about what causes certain conditions and what treatment appears to be effective
- The results may be unique to a particular person without the researcher realizing it or may derive from a special combination of factors that are not obvious
- Research that collects lengthy, detailed information about a person’s background, usually for psychological treatment
Correlation
- a statistical relationship between two variables
- Unlike experimental designs, which involve manipulating or changing conditions, correlational designs are used to study phenomena just as they occur.
- Whether variables occur together- is important to the ongoing search for knowledge about abnormal behavior.
- Correlation does not imply causation.
- Two things occurring togehter does not necessarily mean that one caused the other.
- We do not know from these studies whether A causes B (marital problems cause child problems), whether B causes A (child problems cause marital problems), or whether some third variable C, causes both (genes influence both marital problems and child problems).
- A measure of the extent to which two factors vary together, and thus of how well either factor predicts the other.
Positive correlation
great strength or quantity in one variabe (a great deal of marital distress) is associated with great strength or quantity in the other variable (more child disruptive behavior). At the same time, lower strength or quantity in one variable (marital distress) is associated with lower strength or quantity in the other (disruptive behavior).
Correlation coefficient
- the correlation is represented as +1.00
Plus sign: positive relationship
1.00= “perfect” relationship - Ranges between 0.00 and +1.00 (0.00= no relationship exists)
- The higher the number, the stronger the relationship, whether the number is positive or negative
Negative correlation
as one increases, the other decreases
Directionality
- a correlation allows us to see whether a relationship exists between two variables but not to draw conclusions about whether either variable causes the effects
- Do not know whether A causes B, B causes A, or a third variable, C, causes A and B.
Epidemiology
- study of the incidence, distribution, and consequences of a particular problem or set of problems in one or more populations.
- By tracking a disorder among many people they will find important clues as to why the disorder exists.
- Determining prevalence, the number of people with a disorder at any one time
- Determine the incidence of a disorder, the estimated number of new cases during a specific period
- Branch of medical science concerned with the incidence, distribution, and control of diseases that affect large numbers of people. The study of the incidence, distribution, and consequences of a particular problem or set of problems in a population
Experiment
- the manipulation of an independent variable and the observation of its effects
- Manipulate the independent variable to answer the question of causality
- We are never 100% confident that our experiments are internally valid- that no other explanations are possible- we must be cautious about interpreting our results
Clinical trial
- An experiment used to determine the effectiveness and safety of a treatment or treatments
- Implies a level of formality with regard to how it is conducted
Is not a design by itself but rather a method of evaluation that follows a number of generally accepted rules - These rules cover how you should select the research participants, how many individuals should be included in the study, how they should be assigned to groups, and how the data should be analyzed
- Treatments are usually applied using formal protocols to ensure that everyone is treated the same
- Use both randomization and one or more control conditions- randomized controlled trial
“Randomized clinical trials”
experiments that employ randomization of participants into each experimental group
“Controlled clinical trials”
experiments that rely on control conditions to be used for comparison purposes
Placebo effect
when behavior changes as a result of a person’s expectation of change rather than as a result of any manipulation by an experimenter
Placebo control groups
- the placebo is given to members of the control group to to make them believe they are getting treatment
- People in the untreated group receive something that looks like the medication administered to the treatment group
- In psychological treatments, it is not always easy
- Clients in these types of control groups are often given part of the actual therapy
Control Group
- Answer to the what-if dilemma
- People who are similar to the experimental group in every way except they are not exposed to the independent variable.
- Using a control group allows the researchers to see that their treatment did help the treated participants keep their sleep time from decreasing further.
- Ideally a control group is nearly identical to the treatment group in such factors as age, gender, socioeconomic backgrounds, and the problems they are reporting.
- Would do the same assessments before and after the independent variable manipulation to people in both groups
- Any later differences between the groups after the change would, therefore, be attributable only to what was changed.
Double-blind control
- not only are the participants in the study “blind,” or unaware of what group they are in or what treatment they are given (single blind), but so are the researchers or therapists providing treatment (double blind).
- Eliminates the possibility that an investigator might bias the outcome
- Allegiance effect
- Does not work perfectly in all cases
- Participants and researchers may be able to tell whether or not they have received it
- Participants often know whether or not they are receiving a powerful treatment
- An experimental technique in which biased expectations of experimenters are eliminated by keeping both participants and experimental assistants unaware of which participants have received which treatment
Allegiance effect
- A researcher comparing two treatments who expected one to be more effective than the other might “try harder” if the “preferred” treatment wasn’t working as well as expected.
- If the treatment that wasn’t expected to work seemed to be failing, the researcher might not push as hard to see it succeed.