Chapter X Flashcards
Attrition
the loss of participants in the course of a study when they fail to complete it.
Ceiling Effect
the effect that occurs when scores on a dependent variable bunch up at the maximum score level; compare floor effect.
Complete Replication
replication that includes all the conditions of the original study.
Conceptual Replication
replication that examines the same question investigated in the original study but operationalizes the constructs differently.
Construct Validity
the degree to which the constructs (the
conceptual variables) that researchers claim to be studying are, in fact, the constructs that they are manipulating and measuring.
Debriefing
a conversation with a participant, after data are gathered from that participant, in which the researcher conveys additional information about the study.
Demand Characteristics
cues that influence participants’ beliefs about the hypothesis being tested and the behaviors expected of them.
Differential attrition
significantly different rates of or reasons for participants’ discontinuing a study across the various condi- tions in that study.
Direct Replication
replication in which the researchers follow the procedures used in the original study as closely as possible.
Double-Blind Procedure
in experiments, a procedure in which neither the participants nor the experimenters are aware of who is receiving the actual treatment and who is receiving a placebo.
Experimenter expectancy effects
unintentional ways in which researchers influence their participants to respond in a manner consistent with the researchers’ hypothesis.
External validity
the generalizability of the findings beyond the circumstances of the present study.
Floor effect
an effect that occurs when scores on a dependent variable bunch up at the minimum score level; compare ceiling effect
History
events that occur while a study is being conducted and that are not a part of the experi- mental manipulation or treatment.
Instrumentation
changes that occur in a measuring instrument during the course of data collection (e.g., pretest to posttest changes in the observer’s criteria for rating depression).
Internal Validity
the degree to which we can be confident that a study demonstrated that one variable had a causal effect on another variable.
Manipulation check
an approach that seeks to improve the validity of an experiment by determining whether the procedures used to manipulate an independent variable successfully captured the intended construct.
Masking (blinding)
a procedure in which the par- ties involved in an experiment are kept unaware of the hypothesis being tested and/or the condition to which each participant has been assigned.
Maturation
the ways in which people naturally change over time, independent of their participation in a study.
Partial Replication
replication that includes only some of the conditions of the original study.
Pilot Study
a trial run, usually conducted with a smaller number of participants, prior to initiating the actual experiment.
Placebo Control Group
the group of participants in an experiment who do not receive the core treatment but are led to believe that they are (or may be) receiving it.
Placebo Effect
the effect that occurs when participants’ expectations about how a treatment will affect them influence their responses (on the dependent variable) to that treatment.
Quasi-Experiment
a study that has some features of an experiment but lacks key aspects of experimental control.
Randomized Control Trial
an experiment in which participants are randomly assigned to different conditions for the purpose of examining the effectiveness of an intervention.
Regression to the mean
the statistical concept that when two variables are not perfectly correlated (e.g., scores on a pretest and posttest), more extreme scores on one variable will be as- sociated overall with less extreme scores on the other variable. In experimental design, regression to the mean refers to the fact that when a group is selected because of their above- or below-average scores on a measure, the group’s average scoreon a retest (or on another related measure) will tend to regress toward (i.e., become closer to) the mean score of the overall population.
Replication
the process of repeating a study to determine whether the original findings will be upheld.
Replication and extension
a replication that adds a new design element to the original study.
Selection
a potential threat to internal validity in which, at the start of a study, participants in the various conditions already differ on a characteristic that can partly or fully account for the eventual results.
Sensitivity
the ability of a measure to detect an effect that actually is present.
Statistical conclusion validity
the degree to which the statisti- cal treatment of data is proper and the researchers’ statistical conclusions are sound.
Testing
a potential threat to internal validity in which the act of measuring participants’ responses affects how they respond on subsequent measures.
Ecological Validity
the degree to which responses obtained in a research context generalize to behavior in natural settings; also refers to how well a research setting (e.g., tasks, procedures) corresponds to what people encounter in daily life.
