Description, Explanation, Prediction, and Control: The Objectives of Science
- Scientific method – A systematic method of conducting scientific research in which theories or assumptions are examined in the light of evidence.
- Theory – A formulation of the relationships underlying observed events.
- Within this context, controlling behavior means using scientific knowledge to help people shape their own goals and more efficiently use their resources to accomplish them.
Ethics in Research
- Institutions such as universities and hospitals have review committees, called institutional review boards (IRBs), that review proposed research studies in the light of ethical guidelines.
- Informed consent – The principle that subjects should receive enough information about an experiment beforehand to decide freely whether to participate.
- Confidentiality – Protection of the identity of participants by keeping records secure and not disclosing their identities.
The Scientific Method
1.Formulating a research question.
2.Framing the research question in the form of a hypothesis.
3.Testing the hypothesis.
4.Drawing conclusions about the hypothesis.
- Naturalistic observation – A form of research in which behavior is observed and measured in its natural environment.
- Naturalistic observation provides information on how subjects behave, but it does not reveal why they do so.
- Questions of cause and effect are best approached by means of controlled experiments.
The Correlational Method
- Correlational method – 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.
- The longitudinal study is a type of correlational study in which individuals are periodically tested or evaluated over lengthy periods of time, perhaps for decades.
The Experimental Method
- Experimental method – A scientific method that aims to discover cause-and-effect relationships by manipulating independent variables and observing the effects on the dependent variables.
- Independent variables – Factors that are manipulated in experiments.
- Dependent variables – Factors that are observed in order to determine the effects of manipulating the independent variable.
Examples of Independent and Dependent Variables in Experimental Research
- Experimental group – In an experiment, a group that receives the experimental treatment.
- Control group – In an experiment, a group that does not receive the experimental treatment.
- Random assignment – A method of assigning research subjects at random to experimental or control groups to balance these groups on the characteristics of people that comprise them.
- 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.
- Blind – A state of being unaware of whether one has received an experimental treatment.
- Placebo – An inert medication or bogus treatment that is intended to control for expectancy effects.
- In a single-blind placebo-control study, subjects are randomly assigned to treatment conditions in which they receive either an active drug (experimental condition) or an inert placebo (placebo-control condition), but are kept blind, or uninformed, about which drug they receive.
- Internal validity – The degree to which manipulation of the independent variables can be causally related to changes in the dependent variables.
- External validity – The degree to which experimental results can be generalized to other settings and conditions.
- Construct validity – The degree to which treatment effects can be accounted for by the theoretical mechanisms (constructs) represented in the independent variables.
- 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.
- Researchers must take steps when constructing a sample to ensure that it represents the target population.
- Random sample – A sample that is drawn in such a way that every member of a population has an equal chance of being included.
- By contrast, random assignment refers to the process by which members of a research sample are assigned at random to different experimental conditions or treatments.
- Genotype – The set of traits specified by an individual’s genetic code.
- Phenotype – An individual’s actual or expressed traits.
- Proband – The case first diagnosed with a given disorder.
- Identical, or MZ, twins are important in the study of the relative influences of heredity and environment because differences between MZ twins are the result of environmental rather than genetic influences.
- In twin studies, researchers identify individuals with a specific disorder who are members of MZ or DZ twin pairs and then study the other twins in the pairs.
- Adoptee studies – Studies that compare the traits and behavior patterns of adopted children to those of their biological parents and their adoptive parents.
- Case study – A carefully drawn biography based on clinical interviews, observations, and psychological tests.
- 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.
A-B-A-B Reversal Design
Azrin and Peterson Study
Critical thinking – Adoption of a questioning attitude and careful scrutiny of claims and arguments in the light of evidence.
Some key features of critical thinking:
1.Maintain a skeptical attitude.
2.Consider the definitions of terms.
3.Weigh the assumptions or premises on which arguments are based.
4.Bear in mind that correlation is not causation.
5.Consider the kinds of evidence on which conclusions are based.
6.Do not oversimplify.
Do not overgeneralize.
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