Experimental Psychology Flashcards
the dimension that the experimenter intentionally manipulates. (2) sometimes aspects of the physical environment that can be brought under the experimenter’s direct control.
Independent variable
particular behavior we expect to change because of our experimental treatment. (2) the outcome we are trying to explain.
Dependent variable
specifies the precise meaning of a variable within an experiment. (2) defines a variable in terms of observable operations, procedures, and measurements. (3) it clearly describes the operations involved in manipulating or measuring the variables in an experiment.
Operational Conditioning
explain the precise meaning of the independent variables. (2) includes all the steps that were followed to set up each value of the IV.
Experimental Operational definitions
condition was defined by the electronic equipment set up in the room
The high-anxiety
was defined by the absence of equipment.
low-anxiety condition
describe what we do to measure the variables. (2) describe exactly what procedures we follow to assess the impact of different treatment conditions.
Measured Operational Condition
internal attributes or characteristics that cannot be directly observed
Construct
identifies the set of operations required to measure an external behavior. Uses the resulting as both definition and measurement of a hypothetical construct
Operational condition
It is easy to see why operational definitions are required when we are dealing with constructs. Something that cannot be seen must be defined by observable dimensions before we can deal with it scientifically. However, operational definition is equally important when we are working with variables that can be observe more directly.
Nonconstruct Variables
In setting up experiments and formulating operational definitions, researchers also consider the available scales of measurement for each variable. Many variables can be measured in more than one way. The measurement alternatives differ in the degree of information they provide.
Scales Of Mesurements
The simplest level; classifies items into two or more distinct categories that can be named
Nominal
The next level; the magnitude of each value is measured in the form of ranks
Ordinal
Higher level; measures magnitude or quantitative size using measures with equal intervals between the values. Scales
Interval
highest level. measures magnitude or quantitative size using measures with equal intervals. between all values and a true zero point
Ratio
refers to the consistency of experimental operational definitions and measured operational definitions. (2) means consistency and dependability. Good operational definitions are reliable.
RELIABILITY
degree to which observers agree in their measurement of the behavior. this method is used in a content analysis, when raters must score the qualitative content of subjects’ responses.
Interrater Reliability
the degree to which a person’s scores are consistent across two or more administrations of a measurement procedure.
Test-Retest reliability
measures the degree to which different parts of an instrument (questionnaire or test) that are designed to measure the same variable achieve consistent results.
Interitem Reliability
splitting the test into two halves at random and computing a coefficient of reliability between the scores obtained on the two halves.
Split half reliability
most widely used method for evaluating interitem reliability because it considers the correlation of each test item with every other item; it is like measuring split-half reliability for all possible ways a test could be split up into halves.
Cronbach’s α (Alpha)
means the operational definition accurately manipulates the independent variable or measures the dependent variable. (2) refers to the principle of actually studying the variables that we intend to study.
VALIDITY
degree to which the validity of a manipulation or measurement technique is self-evident. This is the least stringent form of validity because it does not provide any real evidence.
Face validity
means how accurately a measurement procedure samples the content of the dependent variable. depends on whether we are taking a fair sample of the variable we intend to measure.
Content validity
means how accurately a measurement procedure predicts future performance.
Predictive validity
compares scores on the measuring instrument with an outside criterion, but concurrent validity is comparative, rather than predictive.
Concurrent validity
how accurately an operational definition represents a construct. deals with the transition from theory to research application.
Construct validity
to which changes in the dependent variable across treatment conditions were due to the independent variable. (2) establishes a cause-and-effect relationship
Internal validity
they are factors that are not the focus of experiment but can influence the findings. Ex: Time, weather. Level of fatigue
Extraneous variables
occurs when an extraneous variable systematically changes across the experimental conditions.
Confounding
occurs when an event outside the experiment threatens internal validity by changing the dependent variable.
History threat
produced when physical or psychological changes in the subject threaten internal validity by changing the DV.
Maturation threat
occurs when prior exposure to a measurement procedure affects performance on this measure during the experiment.
Testing threat
when changes in the measurement instrument or measuring procedure threatens internal validity.
Instrumentation
when subjects are assigned to conditions on the basis of extreme scores, the measurement procedures is not completely reliable, and subjects are retested using the same procedure to measure change on the DV.
Statistical regression
occurs when individual differences are not balanced across treatment conditions by the assignment procedure.
Selection
occurs when subjects drop out of experimental conditions at different rates.
Subject Morality
when a selection threat combines with at least one other threat
Selection interaction
aspects of the testing situation that need to be controlled (2) aspects of the environment that might affect the participant’s behavior.
Physical variables
to completely remove extraneous variables from an experiment
Elimination
conditions simply means that we keep all aspects of the treatment conditions as nearly similar as possible. (2) extraneous variable is reduced to a single value experienced by all participants
Constancy
controls extraneous physical variables by equally distributing their effects across treatment conditions. (2) a control procedure that achieves group equality by distributing extraneous variable equally
Balancing
are cues within the experimental situation that demand or elicit specific participant responses. (2) a subtle cue that makes participants aware of what the experimenter expects to find or how participants are expected to behave.
Demand Characteristic
when the participants are deliberately kept ignorant of either the group to which they have been assigned or key information about the materials they are assessing
Single blind experiments
false plausible explanation of the experimental procedures to disguise the research hypothesis from the subjects. It is used because we want subjects to respond as normally as possible..
Cover stories
anything that seems to be real but isn’t.
Placebo
any behavior by the experimenter that can confound the experiment. (2) bias, also known as research bias, occurs when a researcher unconsciously affects results, data, or a participant in an experiment due to subjective influence.
Experimenter Bias
an investigator’s expectations about the outcome of a given study unwittingly affect the actual study outcome. (2) a psychological phenomenon wherein high expectations lead to Improved performance in a given area.
Rosenthal effect (Pygmalion effect)
psychological phenomenon wherein high expectations lead to improved performance in a given area.
Double blind experiment
The personal characteristics that an experimenter or volunteer subjects bring to the experimental setting
Personality Variables
The behavior of the experimenter can be an important extraneous variable in an experiment. 2 Social variables, qualities of the relationship between subjects and experimenters, can influence results if they are not carefully controlled.
EXPERIMENTER
tend to hold more liberal social and political attitudes and tend to be less authoritarian than nonvolunteers. Interestingly, people willing to volunteer for experiments also tend to score higher on intelligence tests, on the average, than do nonvolunteers.
Volunteer Subjects
Are those that come about from procedures created by the environment, or context, of the research setting.
Context Variables
