Methods of Studying Psychological Disorders - Chapter 1

What is the process of the scientific method?

Research question, hypothesis, testing hypothesis, and drawing conclusions

What is naturalistic observation?

A form of research where behavior is observed in its natural environment, with minimal or no researcher interference.

Issues with Naturalistic Observation:

The presence of an observer may distort behavior; provides information on how subjects behave but not why they do so.

Correlational Methods

A scientific method of study that examines the relationships between factors or variables expressed in statistical terms.

Correlation Coefficient

A statistical measure of the strength of the relationship between two variables expressed along a continuum that varies between −1.00 and +1.00.

Cross Sectional Studies

Observational research methods that use data from a population at a specific point in time; snapshots essentially

Longitudinal Studies

A type of correlational study in which individuals are periodically tested or evaluated over lengthy periods of time.

Correlation types

Can be negative or positive

Cross sectional research methods - Disadvantages

Cohort effects are likely present, lack of generalizability

Cross sectional research methods - Advantages

Quick and less expensive, typically a larger sample

Longitudinal Research - Advantages

Provides info about age changes over time, more in-depth information per participant

Longitudinal Research - Disadvantages

Expensive, time consuming, less generalizability

Experimental Methods

A carefully controlled scientific procedure that involves the manipulation of variables to determine cause and effect. The Gold Standard.

Dependent Variables

The measured variable

Independent Variables

The manipulated variable

Experimental Group

The group the receives the experimental treatment

Control Group

The group that does not receive the experimental treatment

Random Assignment

A method of assigning research subjects at random to experimental or control groups.

Selection Factor

A type of bias in which differences between experimental and control groups result from differences in the type of participants in the groups, not from the independent variable.

Controlling for Subject Expectancies - Single Blind

Participants are unaware of whether one has received an experimental treatment.

Controlling for Subject Expectancies - Placebo

An inert medication or bogus treatment that is intended to control for expectancy effects.

Controlling for Subject Expectancies - Double Blind

Participants and researchers are uninformed about whether the participants receive active drug or placebo.

Validity

Accuracy; does this measure accurately measure what its intended to.

Reliability

Does this measure output consistent results over time.

Internal Consistency

Different parts of the assessment or research yield consistent results.

Test-Retest Reliability

The test yields similar results on separate occasions.

Interrater Reliability

A research or assessment method that relies on judgments from multiple observers; raters show a high level of agreement in their ratings.

Content Validity

he degree to which the content of a test or measure represents the traits it purports to measure.

Criterion Validity

The degree to which a test correlates with an independent, external criterion or standard.

Construct Validity

The degree to which a test measures the theoretical construct or underlying construct that it purports to measure.

Epidemiological studies

Research studies that track rates of occurrence of particular disorders among different population groups.

Survey method

A research method in which large samples of people are questioned by means of a survey instrument.

Incidence

The number of new cases of a disorder that occurs within a specific period of time.

Prevalence

The overall number of cases of a disorder in a population within a specific period of time.

Random sample

Method of sampling used to increase likelihood of representative sample.

Kinship Studies

A method of study used to understand the roles of heredity and environment in determining behavior. (Think twin studies)

Genotype

The set of traits specified by an individual’s genetic code, inherited.

Phenotype

An individual’s actual or expressed traits.

Case Studies

A carefully drawn biography based on clinical interviews, observations, and psychological tests. Large sets of data specific to one or a small group of people.

Single-case experimental design

A type of case study in which the subject is used as his or her own control.

Reversal design

An experimental design that consists of repeated measurement of a subject’s behavior through a sequence of alternating baseline and treatment phases.