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argument

In the rational method, a set of premise statements that are logically combined to yield a conclusion.

deduction/deductive reasoning

The use of a general statement as the basis for reaching a conclusion about specific examples.

Empirical method

A method of acquiring knowledge in which observation and direct sensory experience are used to obtain knowledge.

hypothesis

A statement that provides a tentative description or explanation for the relationship between variables.

induction/inductive reasoning

The use of a relatively small set of specific observations as the basis for forming a general statement about a larger set of possible observations.

method of authority

A method of acquiring knowledge in which a person relies on information or answers from an expert in the subject area.

method of faith

A variant of the method of authority in which people have unquestioning trust in the authority figure and, therefore, accept information from the authority without doubt or challenge.

method of intuition

A method of acquiring knowledge in which information is accepted on the basis of a hunch or

method of tenacity

A method of acquiring knowledge in which information is accepted as true because it has always been believed or because superstition supports it.

rational method

A method of acquiring knowledge that involves seeking answers by the use of logical reasoning.

refutable hypothesis

A hypothesis that can be demonstrated to be false. That is, the hypothesis allows the possibility that the outcome will differ from the prediction.

variability

A measure of the size of the spread of scores in a distribution.

T/F: You know that a theater ticket costs $30 and you know that you only have $25. Based on this information you decide that you cannot go to the theater. This is an example of using the empirical method.

False

T/F: Using several specific observations as the basis for constructing a general theory is an example of using deduction (or deductive reasoning).

False

T/F: Using a hypothesis to predict how people will behave is an example of induction (or inductive reasoning).

False

T/F: One critical component of the scientific method is that all answers or explanations must be demonstrated empirically.

True

T/F: Humans who participate in a research study are called research subjects.

False

A student who believes that his performance on tests is influenced by wearing a lucky hat is using the

method of tenacity

Seeking answers by using the reference materials in a college library is an example of using the

method of authority

You find some mushrooms growing in your backyard and want to find out whether or not they are poisonous, so you eat a few and see what happens. This is an example of

the empirical method of knowing or acquiring knowledge

When your doctor uses a stethoscope to listen to your heart, the doctor is gathering information by using the

empirical method

An explanation is empirical if it is based on evidence of the

senses

In a chemistry class, a group of students tried mixing two chemicals together to see what would happen. These students are using the

empirical method to gather information

One step in the scientific method involves using a hypothesis to generate a testable prediction. This process is an example of

deduction

If the individuals in a sample have characteristics that are noticeably different from the individuals in the population, then the sample is said to be:

biased

The names of all the students in a class are listed on separate pieces of paper. The teacher places the papers in a hat and mixes them thoroughly before reaching in to draw out five names. The teacher is using:

simple random sampling

A researcher would like to describe and compare the attitudes of four different ethnic groups of students at a local state college. To obtain participants for the study, the researcher should probably use ________

stratified random sampling

If your primary concern is that the composition of your sample should accurately reflect the composition of the population, then you should use:

proportionate stratified sampling

The most commonly used sampling method in psychological research is probably:

convenience sampling

A researcher who obtains a sample of preschool children by selecting individuals from a local daycare center is using:

non-probability sampling

The technique of quota sampling is most similar to:

stratified random sampling

T/F: One concern when selecting a sample is that the accessible population may not be representative of the target population.

True

T/F: When a researcher does not know the exact number of individuals in the population, it is necessary to use a nonprobability sampling method.

True

T/F: The composition of a proportionate stratified random sample usually will not accurately represent the composition of the population.

False

T/F: The most commonly used sampling methods in psychology are nonprobability sampling methods.

True

T/F: Quota sampling allows a researcher to control the composition of a convenience sample.

True

Accessible population

The easily available segment of a target population. Researchers typically select their samples from this type of population.

Biased sample

A sample with different characteristics from those of the population.

Cluster sampling

A probability sampling technique involving random selection of groups instead of individuals from a population.

Convenience sampling, also called accidental sampling and haphazard sampling.

nonprobability sampling method involving selection of individuals on the basis of their availability and willingness to respond.

Law of large numbers

the larger the sample size, the more likely it is that values obtained from the sample will be similar to the actual values for the population.

Nonprobability sampling

A method of sampling in which the population is not completely known, individual probabilities cannot be known, and the selection is based on factors such as common sense or ease with an effort to maintain representativeness and avoid bias.

Population

The entire set of individuals of interest to a researcher. Although the entire population usually does not participate in a research study, the results from the study will be generalized to the entire population. Also known as target population.

Probability sampling

A sampling method in which the entire population is known, each individual in the population has a specifiable probability of selection, and sampling is done using a random process based on the probabilities.

Proportionate stratified random sampling

A probability sampling technique that involves identifying specific subgroups to be included, determining what proportion of the population corresponds to each group, and randomly selecting individual samples from each subgroup such that the proportion in the sample exactly matches the proportion in the population. Also known as proportionate random sampling.

Quota sampling

A nonprobability sampling method; a type of convenience sampling involving identifying specific subgroups to be included in the sample and then establishing quotas for individuals to be sampled from each group.

Random process

A procedure that produces one outcome from a set of possible outcomes. The outcome must be unpredictable each time, and the process must guarantee that each of the possible outcomes is equally likely to occur.

Representative sample

A sample with the same characteristics as the population.

Representativeness

The extent to which the characteristics of the sample accurately reflect the characteristics of the population.

Sample

A set of individuals selected from a population, usually intended to represent the population in a research study.

Sampling

The process of selecting individuals to participate in a research study.

Sampling methods

The variety of ways of selecting individuals to participate in a research study. Also known as sampling techniques or sampling procedures.

Selection bias

When participants or subjects are selected in a manner that increases the probability of obtaining a biased sample. A threat to external validity that occurs when the selection process produces a sample with characteristics that are different from those in the population. Also known as sampling bias.

Simple random sampling

A probability sampling technique in which each individual in the population has an equal and independent chance of selection.

Stratified random sampling

A probability sampling technique involving identifying specific subgroups to be included in the sample, then selecting equal random samples from each pre-identified subgroup.

Systematic sampling

a sample is obtained by selecting every nth participant from a list containing the total population after a random start.

Target population

A group defined by a researcher''s specific interests; see population.

Apprehensive subject role

In a study, a participant''s tendency to respond in a socially desirable fashion rather than truthfully.

Artifact

an external factor that could influence or distort measures. Artifacts threaten both internal and external validity.

Assignment bias

A threat to internal validity that occurs when the process used to assign different participants to different treatments produces groups of individuals with noticeably different characteristics.

Carryover effects

Changes in the scores observed in one treatment condition that are caused by the lingering aftereffects of a specific earlier treatment condition.

Confounding variable

An extraneous variable (usually unmonitored) that is allowed to change systematically along with the two variables being studied. In the context of an experiment, an extraneous variable that changes systematically along with the independent variable and has the potential to influence the dependent variable. A confounding variable is a threat to internal validity.

Correlational research strategy

A general approach to research that involves measuring two or more variables in order to describe the relationship between the variables. The variables are measured and recorded to obtain a set of scores, usually two scores, for each individual; the measurements are then reviewed to identify any patterns of relationship that exist between the variables and to measure the strength of the relationship.

Curvilinear relationship

In a scatter plot o the data for a correlation, a pattern in which the data points tend to cluster in a curved line.

Demand characteristics. Demand characteristics are artifacts and can threaten both internal and external validity.

cues or features of a study that suggest to the participants what the purpose and hypothesis are, and influence the participants to respond or behave in a certain way.

Descriptive research strategy

A general approach to research that involves measuring a variable or set of variables as they exist naturally to produce a description of individual variables as they exist within a specific group.

Double-blind research

A research study in which both the researcher and the participants are unaware of the predicted outcome.

Equivalent time-samples design

A quasi-experimental design that consists of a long series of observations during which a treatment is alternately administered and then withdrawn.

Experimental research strategy

A research strategy that attempts to establish the existence of a cause-and-effect relationship between two variables by manipulating one variable while measuring the second variable and controlling all other variables.

Experimenter bias

Influence of the experimenter''s expectations or personal beliefs on the findings of a study. Experimenter bias is a type of artifact and threatens both internal and external validity.

External validity

The extent to which we can generalize the results of a research study to people, settings, times, measures, and characteristics other than those used in that study.

Extraneous variable

Any variable that exists within a study other than the variables being studied. In an experiment, any variable other than the independent and dependent variables.

Faithful subject role

In a study, a participant''s attempt to follow experimental instructions to the letter and to avoid acting on the basis of any suspicions about the purpose of the experiment.

Fatigue

A threat to internal validity that occurs when prior participation in a treatment condition or measurement procedure tires the participants and influences their performance on subsequent measurements. An example of a testing effect or an order effect.

Field

Any research setting that the participant or subject perceives as a natural environment.

Good subject role

In a study, a participant''s tendency to respond in a way that corroborates the investigator''s hypothesis.

History

A threat to internal validity from any outside event(s) that influences on the participants'' scores in one treatment differently than in another treatment.

Instrumentation, Also known as instrumental bias or instrumental decay.

A threat to internal validity from changes in the measurement instrument that occur during the time a research study is being conducted.

Internal validity

The extent to which a research study produces a single, unambiguous explanation for the relationship between two variables.

Interviewer bias

The influence of the researcher verbally asking participants questions on the participants'' natural responses.

Laboratory

A research setting that is obviously devoted to the discipline of science. It can be any room or space that the subject or participant perceives as artificial.

Linear relationship

In a scatter plot of the data for a correlational study, a pattern in which the data points tend to cluster around a straight line.

Maturation

A threat to internal validity from any physiological or psychological changes that occur in a participant during the time that research study is being conducted and that can influence the participant''s scores.

Multiple-treatment interference

A threat to external validity that occurs when participants are exposed to more than one treatment and their responses are affected by an earlier treatment.

Negativistic subject role

In a study, a participant''s tendency to respond in a way that will refute the investigator''s hypothesis.

Nonexperimental research strategy

A research strategy that attempts to demonstrate a relationship between two variables by comparing different groups of scores, but makes little or no attempt to minimize threats to internal validity.

Novelty effect

A threat to external validity that occurs when individuals participating in a research study (a novel situation) perceive and respond differently than they would in the normal, real world.

Order effects

Whenever individuals participate in a series of treatment conditions and experience a series of measurements, their behavior or performance at any point in the series may be influenced by experience that occurred earlier in the sequence. Order effects include carryover effects and progressive error.

Practice

A threat to internal validity that occurs when prior participation in a treatment condition or measurement procedure provides participants with additional skills that influence their performance on subsequent measurements. An example of a testing effect or an order effect.

Qualitative research

Type of research that is based on observations that are summarized and interpreted in a narrative report.

Quantitative research

Type of research that is based on measuring variables for individual participants or subjects to obtain scores, usually numerical values, that are submitted to statistical analyses for summary and interpretation.

Quasi-experimental research strategy

A research strategy that attempts to limit threats to internal validity and produce cause-and-effect conclusions (like an experiment), but lacks one of the critical components

Reactivity

Participants modification of their natural behavior in response to the fact that they are participating in a research study or the knowledge that they are being measured.

Research design

A general plan for implementing a research strategy. A research design specifies whether the study will involve groups or individual subjects, will make comparisons within a group or between groups, or specifies how many variables will be included in the study.

Research procedure

The exact, step-by-step description of a specific research study.

Research strategy

A general approach to research determined by the kind of question that the research study hopes to answer.

Sensitization, Also known as assessment sensitization or pretest sensitization.

A threat to external validity that occurs when the assessment procedure alters participants so that they react differently to treatment than they would in the real world when the treatment is used without assessment.

Single-blind research

A research study in which the researcher does not know the predicted outcome.

Statistical regression

A statistical phenomenon in which extreme scores (high or low) on a first measurement tend to be less extreme on a second measurement; considered a threat to internal validity because changes in participants'' scores could be caused by regression rather than by the treatments. Also known as regression toward the mean.

Subject roles

The different ways that participants respond to experimental cues based on whatever they judge to be appropriate in the situation. Also known as subject role behavior.

Testing effects

A threat to internal validity that occurs when participants are exposed to more than one treatment and their responses are affected by an earlier treatment. Examples of testing effects include fatigue and practice. Also known as order effects.

Threat to external validity

Any characteristic of a study that limits the generality of the results.

Threat to internal validity

Any factor that allows for an alternative explanation for the results of a study.

Threat to validity

Any component of a research study that introduces questions or raises doubts about the quality of the research process or the accuracy of the research results.

Volunteer bias

A threat to external validity that occurs because volunteers are not perfectly representative of the general population.

A study addressing how many cigarettes a week are smoked by adolescents at a high school is an example of what research approach?

descriptive

The ________ strategy is an approach to research whereby two variables are measured for each individual and the relationship between the variables is examined.

correlational

Experiments allow researchers to:

answer cause-and-effect questions about the relationship between two variables

Any factor that raises doubts about the research results or the interpretation of the results is a:

threat to validity

Any factor that limits the ability to generalize the results of the study is a threat to:

external validity

In which research situation would the study be confounded?

An extraneous variable varies systematically along with the two variables being studied.

A study examining the relationship between humor and memory compares memory performance scores for one group presented with humorous sentences and a second group presented with nonhumorous sentences. The participants in both groups consist of a mixture of males and females. In this study, gender (male/female) is a(n) ________ variable.

extraneous

________ effects occur when environmental events other than the treatment influence the participants' scores in one treatment differently than in another treatment.

History

The tendency for individuals who have extreme scores (high or low) on one measurement and to have less extreme scores on a second measurement is called:

regression toward the mean

Experimental research studies tend to have very ________ internal validity but often have relatively ________ external validity.

high, low

T/F: Qualitative research produces a written report describing and interpreting the results instead of a statistical analysis of the results.

True

T/F: The purpose of the descriptive research strategy is to describe the relationship between two variables.

False

T/F: The extent to which we can generalize the results of a study to other times, situations, environments, is external validity.

True

T/F: An extraneous variable is any variable that is part of a research study but not directly investigated.

True

T/F: A history effect is an outside, environmental variable that influences the participants' scores in one treatment condition differently than in other conditions.

True

Control group

In a research study, the group that receives no treatment or a placebo treatment.

Dependent variable

In an experiment, the variable that is observed for changes in order to assess the effects of manipulating the independent variable. In nonexperiments and quasi-experiments the dependent variable is the variable that is measured to obtain the scores within each group. The dependent variable is typically a behavior or a response measured in each treatment condition.

Directionality problem

A correlational study can establish that two variables are related; that is, that changes in one variable tend to be accompanied by changes in the other variable. However, a correlational study does not determine which variable is the

Experiment

A study that attempts to show that changes in one variable are directly responsible for changes in a second variable. Also known as a true experiment.

Experimental group

The treatment condition in an experiment.

Experimental realism

In simulation research, the extent to which the psychological aspects of the research environment duplicate the real-world environment that is being simulated.

Field study

An experiment conducted in a setting that the participant or subject perceives as a natural environment.

Independent variable

In an experiment, the variable manipulated by the researcher. In behavioral research, the independent variable usually consists of two or more treatment conditions to which participants are exposed.

Levels

In an experiment, the different values of the independent variable selected to create and define the treatment conditions. In other research studies, the different values of a factor.

Manipulation

In an experiment, identifying the specific values of the independent variable to be examined and then creating treatment conditions corresponding to each of these values.

Manipulation check

In an experiment, an additional measure used to assess how the participants perceived and interpreted the manipulation and/or to assess the direct effect of the manipulation.

Matching

The assignment of individuals to groups so that a specific variable is balanced or matched across the groups.

Mundane realism

In simulation research, the extent to which the superficial, usually physical, characteristics of the research environment duplicate the real-world environment that is being simulated.

No-treatment control group, in an experiment...

group or condition in which the participants do not receive the treatment

Placebo

An ineffective, inert substitute for a treatment or medication.

Placebo control group

the participants receive a placebo instead of the actual treatment.

Random assignment

A procedure in which a random process is used to assign participants to treatment conditions.

Randomization

The use of a random process to help avoid a systematic relationship between two variables. The intent is to disrupt any systematic relationship that might exist between extraneous variables and the independent variable.

Simulation

In an experiment, the creation of conditions that simulate or closely duplicate the natural environment in which the behaviors being examined would normally occur.

Third-variable problem

The possibility that two variables appear to be related when, in fact, they are both influenced by a third variable that causes them to vary together.

Treatment condition

In an experiment, a situation or environment characterized by one specific value of the manipulated variable. An experiment contains two or more treatment conditions that differ according to values of the manipulated variable.

The primary purpose of manipulation in an experiment is to

establish the direction of the relationship

Dr. Jones is interested in studying how indoor lighting can influence people's moods during the winter. A sample of 100 households is selected. Fifty of the homes are randomly assigned to the bright-light condition where Dr. Jones replaces all the lights with 100-watt bulbs. In the other 50 houses, all the lights are changed to 60-watt bulbs. After two months, Dr. Jones measures the level of depression for the people living in the houses. In this example, the level of depression is the ________ variable.

dependent

Dr. Jones is interested in studying how indoor lighting can influence people's moods during the winter. A sample of 100 households is selected. Fifty of the homes are randomly assigned to the bright-light condition where Dr. Jones replaces all the lights with 100-watt bulbs. In the other 50 houses, all the lights are changed to 60-watt bulbs. After two months, Dr. Jones measures the level of depression for the people living in the houses. Assuming that the study uses people from different age groups, participant age would be a(n) ________ variable in the experiment.

extraneous

Any variable in a study other than those being directly studied is a(n) ________ variable.

extraneous

A researcher designs a study to determine whether female preschoolers prefer sweetened or unsweetened cereal. The researcher uses a box of sweetened colorful cereal and a box of unsweetened tan colored cereal. The research finds that the group of preschoolers ate more of the sweetened colorful cereal and therefore prefers the sweetened cereal. Which two variables are confounded in this experiment?

color of the cereal and sweetness of the cereal

In an experiment, a researcher must control extraneous variables to prevent them from becoming ________ variables.

confounding

In an experiment, participants are usually assigned to treatments using random assignment. The reason for using random assignment is:

to help control extraneous variables

A researcher has observed that children who eat more sugar tend to show a higher level of activity than children who eat less sugar. However, the researcher suspects that the apparent relationship may be explained by the fact that some children have a higher rate of metabolism which causes them to eat more and to be more active compared to children with a lower rate of metabolism who eat less and are less active. This is an example of ________.

the third-variable problem

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