CH 7 & 8: External Validity of Lab Experiments

placebo effect

when participants’ belief in the efficacy of the treatment is responsible for the results found in a treatment or experiment

experimental demand

Cues about the researcher’s expectations are not limited to ones emitted directly by the experimenter but could involve artifacts in a laboratory setting that are not essential to the experiment, but that inadvertently provoke some form of participant response.

demand characteristics

the totality of all social cues communicated in an experimental context (laboratory or field), which are not a part of the intended manipulation, including those emanating from the experimenter and the setting, and that may alter and therefore place a demand on ( i.e., influence) participants’ responses.

voluntary participants

aware they are under investigation but have made a conscious decision that the potential benefits out-weigh the costs

involuntary participants

research subjects who feel that they have been coerced to spend their time in an investigation and consider it unjustifiable, and therefore vent their displeasure by actively attempting to ruin the study

nonvoluntary participants

unknowingly participate in a study and are unaware of their role in the research

good participants

who attempt to determine the experimenter’s hypotheses and attempt to confirm them

negative participants

who also are interested in learning the study hypotheses so

they can disconfirm them

faithful participants

who are willing to cooperate with almost any of the experimenter’s demands and follow instructions scrupulously, ignoring any hypotheses they might have formed about study expectations

apprehensive participants

who worry the experimenter will use their performance to evaluate their intelligence, morality, etc., and respond to experimental demands accordingly.

monitoring

careful observation of experimenters’ behaviors to ensure that their data transcription and analysis are accurate (e.g., recording the experimenter- participant interaction and comparing the results found by the experimenter with those obtained through the unbiased observers of this interaction.)

weakness of monitoring

does not preclude the possibility of subtle, nonverbal cuing of the participant by the experimenter

double-blind procedure

participants as well as the researcher responsible for administering the study are made unaware of the treatment condition to which participants are (randomly) assigned

mechanized procedures

Instructions, manipulations, and procedures could be presented to participants via audiotape, videotape, or a computer laptop, with respondents’ answers collected using these electronic devices, and data analyzed by an impartial computer.

robustness

A result that is replicable across a variety of settings, persons, and historical contexts

ecological validity

the extent an effect occurs under conditions that are typical or representative in the population

relevance

the external validity issue of the extent an effect obtained is pertinent to events or phenomena that actually occur in the real world

field study

research conducted outside the laboratory, in which the researcher administers the study in participants’ own naturalistic environments

exact replication

an attempt is made to reproduce the results of a previous study by using the same procedures, particularly the same operationalizations, to represent the same constructs

conceptual replication

an attempt is made to reproduce the results of a previous study by using different operational definitions to represent the original constructs

intention-to-treat

include participants in their assigned experimental conditions for purposes of analysis regardless of whether they were exposed to the treatment or not 

crowdsourcing

research that uses the Internet to recruit respondents for participation in online surveys or experiments