Midterm 1 Flashcards
Scientific Method
A set of principles about the appropriate relationship between ideas and evidence.
Empiricism
The belief that accurate knowledge can be acquired through observation.
Theory
A hypothetical explanation of a natural phenomenon.
Hypothesis
A falsifiable prediction made by a theory.
Empirical method
A set of rules and techniques for observation.
Operational Definition
A description of a property in concrete, measurable terms.
Measure
A device that can detect the condition to which an operational definition refers.
Electromyograph (EMG)
A device that measures muscle contractions under the surface of a persons skin.
Validity
The extent to which a measurement and a property are conceptually related.
Reliability
The tendency for a measure to produce the same measurement whenever it is used to measure the same thing.
Power
The ability of a measure to detect the concrete conditions specified in the operational definition.
Demand Characteristics
Those aspects of an observational setting that cause people to behave as they think they should.
Naturalistic Observation
A technique for gathering scientific information by unobtrusively observing people in their natural enviroments.
Double-Blind
An observation whose true purpose is hidden from both the observer and the person being observed.
Frequency Distribution
A graphical representation of measurements arranged by the number of times each measurements was made.
Normal Distribution
A mathematically defined frequency distribution in which most measurements are concentrated around the middle.
Mode
The value of the most frequently observed measurements.
Mean
The average value of a the measurements.
Median
The value that is “in the middle”- i.e. greater than or equal to half of the measurements and less than or equal to half of the measurements.
Range
The value of the largest measurement in a frequency distribution minus the value of the smallest measurement.
Standard Deviation
A statistic that describes the average difference between the measurements in a frequency distribution and the mean of that distribution.
Variable
A property whose value can vary across individuals or over time.
Correlation
Two variables are said to “be correlated” when variations in the value of one variable are synchronized with variations in the value of the other.
Correlation Coefficient
A measure of the direction and strength of a correlation which is signifies by the letter r.
Natural Correlation
A correlation observed in the world around us.
Third-Variable Correlation
The fact that two variables are correlated only because each is casually related to a third variable.
Matched Samples
A technique whereby the participants in two groups are identical in terms of a third variable.
Matched Pairs
A technique whereby each participant is identical to one other participant in terms of a third variable.
Third-Variable Problem
The fact that a casual relationship between two variables cannot be inferred from the naturally occurring correlation between them because of the ever-present possibility of third-variable correlation.
Experiment
A technique for establishing the casual relationship between variables.
Manipulation
The creating of an artificial pattern of variation in a variable in order to determine its casual powers.
Independent Variable
The variable that is manipulated in an experiment.
Experimental Group
The group of people who are treated in a particular way, as compared to the control group, in an experiment.
Control Group
The group of people who are not treated in the particular way that the experimental group is treated in an experiment.
Dependent Variable
The variable that is measured in a study.
Self-Selection
A problem that occurs when anything about a person determines whether he or she will be included in the experimental or control group.
Random Assignment
A procedure that uses a random event to assign people to the experimental group or control group.
Internal Validity
The characteristic of an experiment that establishes the casual relationship between variables.
External Validity
A property of an experiment in which the variables have been operationally defined in a normal, typical, or realistic way.
Population
The complete collection of participants who might possibly be measured.
Sample
The partial collection of people drawn from a population.
Case Method
A method of gathering scientific knowledge by studying a single individual.
Random Sampling
A technique for choosing participants that ensures that every member of a population has an equal chance of being included in the sample.
