Experimental Designs and Methods

These flashcards provide a comprehensive overview of essential concepts, terminology, and methodologies related to experimental designs and methods relevant for MCAT preparation.

What is the main purpose of an experimental study?

To manipulate an independent variable to observe how a dependent variable changes.

What type of variable is manipulated in an experiment?

The independent variable.

What type of variable is measured in response to changes in the independent variable?

The dependent variable.

In a graph of an experiment, where is the independent variable typically placed?

On the x-axis.

Where is the dependent variable typically placed in a graph?

On the y-axis.

Define a confounding variable.

A third variable that affects both the independent and dependent variable, obscuring the true relationship.

What is a mediating variable?

A variable that provides a causal link between two other variables in a relationship.

What does a moderating variable do?

It modulates the intensity of a relationship between two other variables.

What is operationalization in research?

The process of making a variable measurable.

What is a negative control in an experiment?

A group that does not receive the treatment or intervention of interest.

What is a positive control in an experiment?

A group that receives a treatment known to induce the outcome of interest.

What is randomization in experimental studies?

The process of randomly assigning participants to control or treatment groups.

What is blinding in a study?

When participants or researchers do not know which treatment is being administered.

Define a randomized controlled trial (RCT).

An experiment where participants are randomly assigned to either a treatment group or a control group.

What is an observational study?

A study that analyzes relationships among variables without manipulating them.

What is a cross-sectional study?

A study where researchers measure various things about a population at a single point in time.

What is a cohort study?

A longitudinal study that follows a group of subjects sharing a characteristic over time.

What distinguishes case-control studies?

They compare individuals with a specific outcome (cases) to those without it (controls).

What is a case study?

An in-depth investigation of a single individual or small group.

What is a case series?

A descriptive study of a small group of patients with a specific condition.

What are systematic reviews?

Studies that critically assess and combine the outcomes of various research studies on a topic.

What is a meta-analysis?

A statistical technique that combines data from multiple studies and re-analyzes it.

What is the purpose of Institutional Review Board (IRB) approval?

To ensure that research meets ethical standards and protects participants.

List one ethical principle required in research involving humans.

Informed consent.

What is internal validity?

The extent to which we can draw causal conclusions from study data.

What is external validity?

The extent to which study results can be generalized to real-world settings.

What demonstrates construct validity?

It indicates how well a study measures what it intended to measure.

What is content validity?

How well the test covers the full scope of the content being measured.

Define criterion validity.

How well a test predicts performance on a relevant outcome.

What is test-retest reliability?

The consistency of a measure when the same test is administered multiple times.

What does inter-rater reliability refer to?

The degree to which different raters give consistent estimates of the same phenomenon.

What is the difference between subjective and objective measures?

Subjective measures are based on personal opinions, while objective measures are based on factual data.

What is social desirability bias?

The tendency of respondents to answer in a way that is socially acceptable rather than truthfully.

Define acquiescence bias.

The tendency of respondents to answer "yes" when unsure, often leading to misleading data.

What does it mean for a sample to be representative?

The sample's demographics closely reflect the broader population from which it was drawn.

What type of study uses questionnaires to collect data?

Survey research.

What does reliability refer to in research?

The consistency of a measurement or the extent to which results can be repeated.

What does validity refer to in research?

The extent to which a study's results are genuine and applicable to the population of interest.

What are mixed-methods studies?

Studies that combine both quantitative and qualitative research methods.

Describe the hierarchy of evidence in research designs.

It ranks study designs based on the strength of evidence they provide, from RCTs at the top to case reports at the bottom.

What is the goal of observational studies?

To analyze relationships among variables without manipulation.

What are longitudinal designs?

Studies that gather data over an extended period of time to assess changes.

What is the main goal of biomedical research?

To establish cause-and-effect relationships.

What is the difference between retrospective and prospective studies?

Retrospective studies look back over time, while prospective studies follow subjects moving forward.