PBSI 245 Chapter 6: Experiments in the Real World

Flashcards covering key vocabulary related to experimental design, threats to confidence, and generalization in real-world experiments, based on PBSI 245 Chapter 6 lecture notes.

randomized comparative experiments

An experimental setup where all subjects are treated exactly alike, except for the specific treatments being compared.

placebo effect

The phenomenon where subjects experience an effect from a treatment, even if it's inactive (a placebo), simply because they believe they are receiving a real treatment.

treatment group

The group of subjects in an experiment that receives the specific treatment being studied.

control group

The group of subjects in an experiment that receives a placebo or no active treatment, serving as a baseline for comparison with the treatment group.

confounding variable

A variable in an experiment that is not controlled and can influence the outcome, making it difficult to determine the true effect of the treatment.

experimenter effect

Threats to experimental results associated with the inherent characteristics of the experimenter or proctor.

experimenter expectancy

The (un)conscious expectations of the experimenter or proctor that can inadvertently influence the outcomes of an experiment.

demand characteristics

Participants' expectations or beliefs about the aims of a study, which can cause them to alter their behavior or responses.

good subject response

A type of demand characteristic where participants try to behave in a way they believe will support the experimenter's hypothesis.

social desirability

Participants' tendency to respond or behave in a way that is perceived as socially acceptable or favorable.

Hawthorne effect

The phenomenon where participants change their behavior simply because they are aware of being observed in a study.

double-blind experiment

An experimental design where neither the subjects nor the individuals working directly with them know who is in the treatment group and who is in the control group, to minimize bias.

refusals

Subjects who are selected for an experiment but decline to participate.

nonadherers

Subjects who do not completely follow the specified treatment protocols of an experiment.

dropouts

Subjects who begin an experiment but do not complete it.

meta-analysis

A comprehensive statistical technique that combines and synthesizes the results of multiple primary empirical studies on a similar topic.

explanatory variable

A variable (also known as an independent variable or IV) that is manipulated or observed to determine its effect on a response variable.

factorial design

An experimental design involving two or more explanatory (independent) variables, allowing for the examination of their individual and combined effects.

interaction

When the effect of one independent variable on the dependent variable changes depending on the level of another independent variable.

main effect

The overall effect of a single independent variable on the dependent variable, averaged across the levels of all other independent variables in a factorial design.

completely randomized design

An experimental design where subjects are assigned to treatment groups entirely at random.

matched pairs design

An experimental design where subjects are first paired based on similarity, and then one subject from each pair is randomly assigned to a different treatment group.

block design

An experimental design where subjects are first grouped into similar 'blocks' based on a potential confounding variable, and then treatments are randomly assigned within each block.

block

A group of subjects in an experimental design who are similar on a characteristic that might influence the response to treatments, used to reduce variability.