Flashcard--Collecting Data

Front

What is a sampling plan that may introduce bias when collecting data?

Back

A survey mailed to all registered voters where only those who returned the survey make up the sample can introduce bias.

Front

What is the definition of an observational study?

Back

An observational study involves observing, recording, and measuring data without manipulating the environment.

Front

What is the placebo effect?

Back

The placebo effect occurs when members of the control group believe they are improving without receiving the actual treatment.

Front

What is a simple random sample?

Back

A simple random sample is a sampling method where every individual has an equal chance of being selected, such as pulling names from a box.

Front

What is a convenience sample?

Back

A convenience sample is a non-random sampling method where individuals are selected based on their easy availability, such as interviewing the first 30 students who enter a school.

Front

What is the difference between a stratified sample and a simple random sample?

Back

A stratified sample involves dividing the population into subgroups and randomly sampling from each, while a simple random sample does not consider subgroups.

Front

What is the role of an explanatory variable in data collection?

Back

An explanatory variable is a variable that is manipulated to observe its effect on a response variable.

Front

What is a systematic sample?

Back

A systematic sample is a sampling method where individuals are selected at regular intervals from a list.

Front

What is the definition of a control group in an experiment?

Back

A control group is a group of subjects that does not receive the experimental treatment and is used as a benchmark to measure the effects of the treatment.

Front

What is the significance of random selection in sampling?

Back

Random selection helps to ensure that the sample is representative of the population, reducing bias.