STATISTICS - EXPERIMENT DESIGN

Convenience Sample

A sample of individuals easily accessible to the researcher, often leading to bias.

Systematic Random Sample

A sample created by selecting every kth individual from an ordered list of the population.

Question of Interest

The specific question a researcher is trying to answer.

Statistic

A numerical value that describes a sample, like the average height of students.

Nonresponse

Occurs when an individual selected for a survey doesn't participate, introducing bias.

Simple Random Sample

A method where every individual and every group has an equal chance of being selected.

Multistage Random Sample

A sampling technique involving multiple stages of random selection.

Geographic Limitation

A bias that occurs when a study is limited to a specific geographic area.

Census

A survey that attempts to collect data from every single member of a population.

Wording Effects

The influence of question phrasing, which can introduce bias.

Cluster Random Sample

A sampling method where the population is divided into groups, and a sample of these clusters is chosen.

Parameter

A numerical value that describes an entire population, typically unknown.

Undercoverage

A bias that happens when some members of the population are omitted from the sampling frame.

Response Bias

The tendency for individuals to give inaccurate or untruthful answers.

Stratified Random Sample

A sampling method that divides the population into homogeneous subgroups and samples from each.

Bias

A systematic error in a study that results in over- or underestimation of the true population parameter.

Population

The entire group of individuals that a researcher is interested in studying.

Voluntary Response Sample

A sample made up of individuals who choose to participate, often leading to bias.

Statistical Inference

The process of using data from a sample to draw conclusions about a larger population.

Experiment

A study where the researcher applies a treatment to a group of subjects.

Factors

Independent variables manipulated by the researcher in an experiment.

Double Blind Test

An experiment where neither the subjects nor the researchers know who receives the treatment.

Statistically Significant

A result that is unlikely to have occurred by random chance.

Multiple Analysis

The practice of analyzing data in different ways to ensure robust findings.

Control Group

The group that does not receive the treatment, serving as a baseline for comparison.

Replication

The process of repeating an experiment with different groups to confirm original findings.

Observational Study

A study where researchers observe variables without attempting to influence outcomes.

Lack of Realism

A limitation when the experimental setting is artificial and results can't be generalized.

Blind Test

An experimental procedure where subjects do not know if they are receiving treatment or placebo.

Random Assignment

The process of assigning subjects to experimental groups by chance.

Confounding Variables

Extraneous variables that influence both independent and dependent variables.

Treatment

The specific experimental condition applied to the subjects.

Media Bias

The tendency for news outlets to slant reporting, influencing public perception.

Placebo

An inactive substance or treatment given to the control group to mimic the treatment.

Anecdotal Evidence

Evidence based on personal accounts, often unreliable for broad conclusions.

Response Variable

The dependent variable measured to see if it's affected by the treatment.

Psychological Effects

Changes in health or behavior caused by beliefs or expectations about a treatment.

Control

The effort to keep all conditions constant except for the treatment.

Subjects

The individuals or units on whom the experiment is conducted.