RESEARCH IN ABNORMAL PSYCHOLOGY Flashcards
is the systematic search for facts through the use of careful observations and investigations
Research
Clinical researchers face certain challenges that make their work very difficult:
Measuring unconscious motives
Assessing private thoughts
Monitoring mood changes
Calculating human potential
The case study:
- Can provide a detailed, interpretative description of a person’s life and psychological problems
- Can be a source of new ideas about behavior
- May offer tentative support for a theory
- May challenge a theory’s assumptions
- May inspire new therapeutic techniques
- May offer opportunities to study unusual problems
Limitations in the case study
- Reported by biased observers
- Relies on subjective evidence
- Has low internal validity
- Provides little basis for generalization
- Has low external validity
- These limitations are addressed by the two other methods of investigation
is the degree to which events or characteristics vary with each other
Correlation
is a research procedure used to determine the “co-relationship” between variables
The correlational method
The people chosen for a study are its subjects or participants, collectively called a __
sample
The sample must be representative of the larger population
Describing a Correlation
Correlational data can be graphed and a “line of best fit” can be drawn
Positive correlation (slope is upward and to the right) = variables change in the same direction
Negative correlation (downward slope) = variables change in the opposite direction
Unrelated (no slope) = no consistent relationship
the magnitude
The magnitude (strength) of a correlation is also important High magnitude = variables which vary closely together; fall close to the line of best fit Low magnitude = variables which do not vary as closely together; loosely scattered around the line of best fit
Advantages of the correlational method:
Has high external validity Can generalize findings Can repeat (replicate) studies on other samples
Difficulties with correlational studies:
Lack internal validity
Results describe but do not explain a relationship
Results say nothing about causation
There are two special forms of correlational study
-Epidemiological studies Reveal the incidence and prevalence of a disorder in a particular population
Incidence = number of new cases that emerge in a given period
Prevalence = total number of cases in a given period
-Longitudinal studies -Researchers observe the same individuals on many occasions over a long period
The Experimental Method
An experiment is a research procedure in which a variable is manipulated and the manipulation’s effect on another variable is observed
Manipulated variable = independent variable
Variable being observed = dependent variable
remember
Researchers must try to eliminate all confounds – variables other than the independent variable that may also be affecting the dependent variable
Three features are included in experiments to guard against confounds:
A control group
Random assignment
Blind design
is a group of research participants who are not exposed to the independent variable, but whose experience is similar to that of the experimental group
By comparing the two groups, researchers can better determine the effect of the independent variable
A control group
REMEMBER
To avoid bias by the participant, experimenters employ a “blind design,” in which participants are kept from knowing which assigned group (experimental or control) they are in
One strategy for this is providing a placebo – something that simulates real therapy but has none of its key ingredients
REMEMBER
To avoid bias by the experimenter, experimenters employ a “double-blind design,” in which the experimenters and the participants are kept from knowing which condition of the study participants are in
Often used in medication trials
Clinical researchers often must settle for designs that are less than ideal and include:
Quasi-experimental designs
Natural experiments
Analogue experiments
Single-subject experiments
, investigators do not randomly assign participants to groups, but make use of groups that already exist
Example: Children with a history of child abuse
In quasi-experimental, or mixed designs
, nature manipulates the independent variable and the experimenter observes the effects
In natural experiments
_Psychological impact of flooding
These events cannot be replicated at willBroad generalizations cannot be made
allow investigators to freely manipulate independent variables while avoiding ethical and practical limitations
Analogue experiments
In a single-subject experiment, a single participant is observed both before and after manipulation of an independent variable
In a single-subject experiment,
Experiments rely on baseline data to set a standard for comparison
An example is the ABAB, or reversal, design
, a participant’s reactions are measured during a baseline period (A), after the introduction of the independent variable (B), after the removal of the independent variable (A), and after reintroduction of the independent variable (B)
In an ABAB (reversal) design
The participant is, essentially, compared against himself or herself under different conditions rather than against control subjects
Single-subject experiments are similar to individual case studies
Both focus on one subject only
Both have low external validity
However, the single-subject experiment has higher internal validity than the case study, given the manipulation of an independent variable
