Chapter Two: Research in Abnormal Psychology

Schizophrenia

severe disorder that causes people to lose contact with reality.

Prevalence

total number of cases in the population during a given period.

Epidemiological Studies

determine the incidence and prevalence of a problem in a particular population.

Incidence

number of new cases that emerge in a population during a given period of time.

Analogue Experiments

experimenters induce lab participants to behave in ways that seem to resemble real- life abnormal behavior.

Clinical significance

indicates whether the amount of improvement is meaningful in the persons life.

Case Study

a detailed description of a persons life and psychological problems.

Statistical significance

indicates whether a participants improvement in functioning occurred because of treatment.

Institutional Review Boards

committees of five or more members who review and monitor every study conducted at a research facility, starting at proposal.

Longitudinal Studies

researchers observe the same individuals on many occasions over a long period of time.

Correlational method

research procedure used to determine correlation between variables.

Positive direction of line of best fit

when variables change the same way. shows positive correlation

Natural Experiments

nature itself manipulates the independent variable while the experimenter observes the effects.

Correlation

the degree to which events /characteristics vary with each other.

Negative direction of line of best fit

when variables change in different ways. shows negative correlation

Single Subject Experiments

a single participant is observed both before and after the manipulation of an independent variable.

Clinical practitioners

assess, diagnose, and treat individual clients.

Control group

a group of research participants who are not exposed to the independent variable under investigation.

random assignment

Matched design minimizes confounding variables caused by not using \________.

schizophrenia

severe disorder that causes people to lose contact with reality

case study

focused on one individual

Case Study

a detailed description of a persons life and psychological problems

correlation

the degree to which events / characteristics vary with each other

correlational method

research procedure used to determine correlation between variables

subjects / participants

people chosen for a study

sample

collective name for participants in a sample

positive direction

when variables change the same way

negative direction

when variables change in different ways

magnitude

how closely the two variables correspond

the number represents its magnitude

the closer it is to zero, the lower the relationship the variables have

p < .05

findings are statistically significant and are thought to reflect the larger population

lack internal validity

describes the relationship between two variables, but doesnt explain it

experiment

research procedure in which a variable is manipulated and the manipulations effect on another variable is observed

control group

a group of research participants who are not exposed to the independent variable under investigation

experimental group

the participants who are exposed to the independent variable

statistical significance

indicates whether a participants improvement in functioning occurred because of treatment

clinical significance

indicates whether the amount of improvement is meaningful in the persons life

Random Assignment

any selection procedure that ensures that every participant in the experiment is as likely to be placed in one group as the other

double-masked design

prevents against both patient bias and experimenter bias

triple-masked design

experimenters arrange for judges to assess and analyze the outcomes, and the judges are also kept unaware of group assignments

Alternative Research Designs

designs that intermix elements of both correlational and experimental studies

Matched Designs

researchers match the experimental participants with control participants who are similar in age, sex, socioeconomic status, etc

make use of groups that already exist in the world (ex

effects of abuse on children

Natural Experiments

nature itself manipulates the independent variable while the experimenter observes the effects

Analogue Experiments

experimenters induce lab participants to behave in ways that seem to resemble real-life abnormal behavior

Single-Subject Experiments

a single participant is observed both before and after the manipulation of an independent variable

Longitudinal Studies

researchers observe the same individuals on many occasions over a long period of time

Epidemiological Studies

determine the incidence and prevalence of a problem in a particular population

incidence

number of new cases that emerge in a population during a given period of time

prevalence

total number of cases in the population during a given period

Institutional Review Boards

committees of five or more members who review and monitor every study conducted at a research facility, starting at proposal

Why are IRBs flawed?

ethical principles cant always be broken down into simple guidelines

nomothetic understanding

a general understanding of the nature, causes, and treatments of abnormal functioning, in the form of laws or principles

scientific method

the process of systematically gathering and evaluating information, through careful observations, to understand a phenomenon

hypothesis

a hunch or prediction that certain variables are related in certain ways

internal validity

the accuracy with which a study can pinpoint one factor as the cause of a phenomenon

external validity

the degree to which the results of a study may be generalized beyond that study

correlation

the degree to which events or characteristics vary along with each other

experiment

a research procedure in which a variable is manipulated and the effect of the manipulation on another variable is observed

independent variable

the variable in an experiment that is manipulated to determine whether it has an effect on another variable

dependent variable

the variable in an experiment expected to change as the independent variable is manipulated

confounding variable

a variable other than the independent variable that is also acting on the dependent variable

control group

a group of participants who are not exposed to the independent variable

experimental group

the participants who are exposed to the independent variable under investigation

placebo therapy

a pretend treatment that the participant in an experiment believes to be genuine

quasi-experimental design

A research design that fails to include key elements of a “pure” experiment and/or intermixes elements of both experimental and correlational studies. Also called a mixed design

correlation coefficient

signifies magnitude and direction of line of best fit

masked design

individuals are kept unaware of their assigned group