Introduction to Statistics: Designing Studies and Data Collection

Flashcards covering key vocabulary and concepts from the 'Introduction to Statistics: Designing Studies and Data Collection' lecture, including types of variables, study designs, limitations, and elements of designed experiments.

Explanatory Variable

A variable that may have an effect on another variable.

Response Variable

A variable that is affected by an explanatory variable.

Observational Study

A study where specific characteristics are observed and measured without attempting to modify the individuals being studied.

Experiment

A study where some treatment is applied to individuals (experimental units) to observe its effects.

Correlation

A strong association between two variables.

Causation

The relationship between cause and effect.

Limitation of Observational Studies

Can provide evidence of naturally occurring associations between variables but cannot, by themselves, show a causal connection.

Confounding Variable

A variable that was not accounted for and may actually be important, potentially causing misleading or spurious correlations. Also known as a lurking or conditional variable.

Experimental Units

The individuals in experiments, often called subjects when they are people.

Replication (in experiments)

The repetition of an experiment on more than one individual, requiring sample sizes large enough to observe treatment effects.

Randomization (in experiments)

Assigning experimental units to treatment groups randomly to ensure potential lurking variables are spread equally among groups, making planned treatments the only difference.

Control (in experiments)

A strategy in experimental design to manage the influence of the power of suggestion or participant expectations, often by using a placebo.

Placebo Effect

The phenomenon where the expectations of a study participant can be as important as the actual medication or treatment received, leading to reported improvements even from an untreated subject.

Placebo

A harmless and ineffective pill, medicine, or procedure used for psychological benefit or for comparison to other treatments in research, having no medicinal effect.

Blinding

A technique in which the subject does not know whether they are receiving a treatment or a placebo, used to mitigate the placebo effect.

Double-Blind

A technique where neither the subject nor the experimenter knows whether the subject is receiving the treatment or a placebo.

Gold Standard (in experiments)

Randomness with placebo/treatment groups, considered highly effective for experimental design.