Research Methods Chapter 3
Constructs
are hypothetical attributes or mechanisms that help explain and predict behavior in theory
operational definition
is a procedure for indirectly measuring and defining a variable that cannot be observed or measured directly. specifies a measurement procedure.
Validity
the degree to which the measurement process measures the variable that it claims to measure
Face Validity
an unscientific form of validity demonstrated when a measurement procedure superficially appears to measure what it claims to measure
Concurrent Validity
when scores obtained from a new measure are directly related to scores obtained from an established measure of the same variable
Predictive validity
demonstrated when scores obtained from a measure accurately predict behavior according to a theory
Construct Validity
requires that the scores obtained from a measurement procedure behave exactly the same as the variable itself
Convergent Validity
demonstrated by a strong relationship between the scores obtained from two or more different methods of measuring the same construct
Divergent Validity
demonstrated by showing little or no relationship between the measurements of two different constructs
Reliability
is the stability or consistency of the measurement
Observer Error
Environmental Changes
Participant Changes
Common Sources of Error
test-retest reliability
is established by comparing the scores obtained from two successive measurements of the same individual and calculating a correlation between the two sets of scores
inter-rater reliability
is the degree of agreement between two observers who simultaneously record measurements of the behavior
Split-half Reliability
is obtained by splitting the items on a questionnaire or test in half, computing a sperate score for each half, and then calculating the degree of consistency between the two scores for a group of participants
Nominal Scale
simply represent qualitative differences in the variable measured. Have different names but are not related to each other in any systematic way.
Ordinal Scale
have different names and are organized sequentially. Consists of a series of ranks.
Self-Report Measures
most direct way to assess a construct. participant answers questions about themselves. A disadvantage is that participants can lie.
Physiological Measures
involve brain imaging techniques such as PET scans and MRIs. researchers monitor activity levels in specific areas of the brain during different kinds of activity.
Desynchrony
The lack of agreement between two measures and confuses interpretation of results
Ceiling effect
the clustering of scores at the high end of a measurement scale, allowing little or no possibility of increases in value
Floor Effect
the clustering of scores at the low end of a measurement scale, allowing little or no possibility of decreases in value
Experimenter Bias
occurs when the measurements obtained in a study are influenced by the experimenter's expectation or personal beliefs regarding the outcome of the study
Single-blind Study
if the researcher does not know the predicted outcome
Double-blind Study
if both the researcher and the participants are unaware of the predicted outcome
Demand Characteristics
refers to any of the potential cues or features of a study that suggest to the participants what the purpose and hypothesis is, and influence the participants to respond or behave in a certain way
Reactivity
occurs when participants modify their natural behavior in response to the fact that they are participating in a research study or the knowledge that they are being measured
Good Subject Role
Negativistic Subject Role
Apprehensive Subject Role
Faithful Subject Role
Subject Roles
Good Subject Role
A participant's tendency to respond in a way that is expected to corroborate the investigator's hypothesis
Negativistic Subject Role
in a study, a participant's tendency to respond in a way that is expected to refute the investigator's hypothesis
Apprehensive Subject Role
in a study, a participant's tendency to respond in a socially desirable fashion rather than truthfully
Faithful Subject Role
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 te experiment
laboratory
is any setting that is obviously devoted to the discipline of science. any room or any space that the subject or participant perceives as artificial
Self-Report Measures
Physiological Measures
Behavioral Measures
Modalities of Measurement