Research Methods Chapter 6
- Assignment Bias
- History
- Environmental Variables
- Regression to the Mean
- Maturation
- Instrumentation
- Testing Effects
Threats to Internal Validity
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, but does not attempt to describe or explain relationships between variables
Linear Relationships
shows the changing values of two variables, a pattern in which the data points tend to cluster around a straight line
Curvilinear Relationship
graph showing the changing values of two variables, a pattern in which the data points tend to cluster around a curved line
Positive Relationship
a relationship in which the two variables or measurements tend to change together in the same direction
Negative Relationship
a relationship in which the two variables or measurements tend to change together in opposite directions
Correlational Research Strategy
General approach to research that involves measuring two or more variables for each individual to describe the relationship between the variables
Experimental Research Strategy
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
Quasi-experimental Research Strategy
a strategy that attempts to limit threats to internal validity and produces cause and effect conclusions but lacks either manipulation or control
Nonexperimental Research Strategy
a strategy that attempts to demonstrate a relationship between two variables by comparing different groups of scores but makes no attempt to minimize threats to internal validity or to explain the relationship
Research Design
specifies whether the study will involve groups or individual participants, will make comparisons within a group or between groups, and how many variables will be included in the study
Research Procedure
is an exact, step-by-step description of a specific research study
External Validity
refers to 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
Internal Validity
produces a single, unambiguous explanation for the relationship between two variables
- Selection Bias
- College Student
- Volunteer Bias
- Participant Characteristics
- Cross-species generalization
Threats to External Validity: Category 1
- Novelty effect
- Multiple-treatment interference
- Experimenter characteristics
Threats to External Validity: Category 2
- Sensitization
- Generality across response measures
- Time of measurement
Threats to External Validity: Category 3
Extraneous Variable
any variable in a research study other than the specific variables being studied
Confounding Variable
is an extraneous variable (usually unmonitored) that changes systematically along with the two variables being studied. provides an alternative explanation for the results
- Assignment Bias
- History
- Environmental Variables
- Regression to the Mean
- Maturation
- Instrumentation
- Time-Related Variables
Threats to Internal Validity
experimenter bias
occurs when the experimenter's expectation or personal beliefs regarding the outcome of the study influence the findings of a study.