2: The Methods of Psychology Flashcards
Empiricism
Originally a Greek school of medicine that stressed the importance of observation, and now generally used to describe any attempt to acquire knowledge by observing objects or events
Scientific Method
A set of rules and techniques that allow researchers to avoid the illusions, mistakes and erroneous conclusions that simple observation can produce
Theory
A hypothetical account of how and why a phenomenon occurs, usually in the form of a statement about the causal relationship between two or more properties
Hypothesis
A specific and testable prediction that is usually derived from a theory
Verifiable
Something that can be checked by objective measures
Deduction
Drawing inferences where the conclusion must be true if the premises are true
Induction
The process of establishing general truths based on a limited set of observations
Empirical Method
A set of rules and techniques for observations
Operational Definition
A description of an abstract property in terms of a concrete condition that can be measured
Measure
A device that can detect the measurable events to which an operational definition refers
Electromyograph (EMG)
A device that measures muscle contractions under the surface of a person’s skin
Validity
The characteristic of an observation that allows one to draw accurate inferences from it
Construct Validity
The tendency for an operational definition and a property to have a clear conceptual relation
Predictive Validity
The tendency for an operational definition to be related to other operational definitions of the same property
Reliability
The tendency for a measure to produce the same result whenever it is used to measure the same thing
Power
The tendency for a measure to produce different results when it is used to measure different things
Case Method
A method of gathering scientific knowledge by studying a single individual
Population
The complete collection of people, objects or events that can possibly be measured
Sample
The partial collection of people, objects or events that are measured in a study
Law of Large Numbers
A statistical law stating that as a sample size increase, the attributes of a a sample will be closely reflect the attributes of the population from which the sample was drawn
Frequency Distribution
A graphic representation of the measurements of a sample that are arranged by the number of times each measurement was observed
Normal Distribution
A frequency distribution in which most measurements are concentrated around the mean and fall of towards the tails, and the two sides of the distribution are symmetrical
Mode
The value of the most frequently observed observation
Mean
The average value of the observation, calculated as the sum of all the observations divided by the number of observations
Median
The value that is greater than or equal to the values of half the observations and less than or equal to half the values of the observations
Range
The numerical difference between the smallest and largest measurements in a frequency difference
Standard Deviation
An estimate of the average difference between each observation and the mean in the population distribution
Variance
The average deviation of each observation from the mean
Statistically Significant
The observed effect is not due to chance
Effect Size
An objective and standardised measure of the magnitude of an observed effect
Demand Characteristics
Those aspects of an observational setting that cause people to behave as they think an observer wants or expects them to behave
Naturalistic Observation
A method of gathering scientific knowledge by unobtrusively observing people in their natural environments
Double-Blind Observation
An observation whose true purpose is hidden from the researcher and the participant
Variable
A property whose value can vary or change
Correlation
The ‘co-relationship’ or pattern of covariation between two variables occurs when variations in the value of one value are synchronised with variations in the value of the other
Correlation Coefficient
A statistical measure of the direction and strength of a correlation, symbolised by the letter r
Covariance
A measure of how much two variable change together
Third-Variable Correlation
Two variables are correlated only because each is causally related to a third variable
Natural Correlation
A correlation observed between naturally occurring variables
Matched Samples
An observational technique that involves matching the average of the participants in the experimental and control groups in order to eliminate the possibility that a third variable (and not the independent variable) caused changes in the dependent variable
Matched Pairs
An observational technique that involves matching each participant in the experimental group with a specific participant in the control group in order to eliminate the possibility that a third variable (and not the independent variable) caused changes in the dependent variable
Third-Variable Problem
A causal relationship between two variables cannot be inferred from the correlation between them because of the ever-present possibility of third-variable correlation
Experiment
A technique for establishing the causal relationship between variables
Manipulation
A characteristic of experimentation in which the researcher artificially creates a pattern of variation in an independent variable in order determine its causal powers. Manipulation usually results in the creation of an experimental group and a control group.
Independent Variable
The variable that is manipulated in an experiment
Experimental Group
The group of people who are exposed to an experiment condition under investigation
Control Group
The group of people matched to an experimental group but not exposed to the condition under investigation
Dependent Variable
The variable that is measured in a study
Randomization
A procedure using random assignment to ensure that a participant’s inclusion in the experimental or control group is not determined by a third variable
Self-Selection
The problem that occurs when a participant’s inclusion in the experimental or control group is determined by the participant
Internal Validity
The characteristic of an experiment that allows one to draw accurate inferences about the causal relationship between an independent and dependent variable
External Validity
A characteristic of an experiment in which the independent and dependent variables are operationally defined in a normal, typical or realistic way
Random Sampling
A technique for choosing participants that ensures that every member of a population has an equal change of being included in the sample
Quantitative Research
Uses systematic, scientific investigation in order to measure and quantify phenomena
Qualitative Research
Interested in gaining an in-depth understanding of the human experience and behaviour
Informed Consent
An agreement to participate in a study made by an audibly who has been informed of all the risks that participation may entail
Debriefing
A verbal description of the true nature and purpose of a study that psychologists provide to people after they have participated in the study
