Conducting Experiments

What are the two main types of sampling methods in research?

Probability sampling and nonprobability sampling.

When should probability sampling be used?

When it is important to accurately describe the population.

What is the relationship between sample size and statistical significance?

Increasing sample size increases the likelihood of statistically significant results.

What is the first step researchers must take before conducting an experiment?

Supply participants with the information necessary for informed consent.

What are straightforward manipulations in research?

Manipulations that use instructions and other stimuli to manipulate an independent variable.

What is the purpose of staged manipulations?

To create a psychological state in participants or to simulate a real-world situation.

What is the strength of manipulation in research?

The potential amount of impact of the independent variable on the dependent variable.

What are the two considerations regarding the strength of manipulation?

The strongest manipulation may rarely occur in real life, and it should be strong within ethical bounds.

What is the cost difference between straightforward and staged manipulations?

Straightforward manipulations are less costly than complex, staged experimental manipulations.

What are self-reports in the context of measuring dependent variables?

Measures that require participants to describe themselves.

What are behavioral measures?

Direct observations of behaviors that may need to be quantified.

What are physiological measures?

Recordings of bodily responses, such as GSR, EMG, EEG, MRI, and fMRI.

What is the significance of using multiple measures for a dependent variable?

It increases confidence in results if the independent variable affects several measures similarly.

What is a ceiling effect?

A problem where the independent variable appears to have no effect because participants reach maximum performance.

What is a floor effect?

A problem that occurs when a task is too difficult for most participants to perform well.

What are demand characteristics in research?

Features of an experiment that could inform participants of the study's purpose.

What is the placebo effect?

Improvement in behavior simply from administering an apparent treatment.

What is a placebo control group?

Participants who receive an inert substance instead of the experimental treatment.

What are expectancy effects?

The impact of an experimenter's bias on the outcome of a research study.

What is a single-blind experiment?

An experiment where the participant is unaware of whether they receive a placebo or actual treatment.

What is a double-blind experiment?

An experiment where neither the participant nor the experimenter knows which treatment is given.

What is a pilot study?

A trial run with a small number of participants to test the research design.

What is a manipulation check?

An attempt to directly measure whether the independent variable manipulation has the intended effect.

What is preregistration in research?

The process of identifying and articulating research questions, hypotheses, and analysis plans before data collection.

What is the purpose of statistical analyses in research?

To examine and interpret the pattern of results and determine relationships between variables.

What is the role of peer review in research publication?

To evaluate research papers submitted to journals for quality and validity.