Understanding Observational Studies, Census, Sample, and Bias

What is an observational study?

• A study where the researcher actively intervenes in the study subjects.

• A study where the researcher only observes without intervention.

• A study based solely on historical data.

• A study that predicts future outcomes without current data.

What is the main difference between a census and a sample?

• A census collects data from a small group, while a sample collects data from the entire population.

• A census is quicker to conduct than sampling.

• A census collects data from every member of the population, while a sample collects data from a subset.

• A sample is more accurate than a census.

Which of the following is a type of bias that can occur in studies?

• Sampling bias

• Color bias

• Speed bias

• Height bias

What is sampling bias?

• Bias that occurs when the sample represents certain segments of the population more than others.

• Bias that occurs due to the time the study was conducted.

• Bias in choosing the sample size.

• Bias due to the method of data collection.

Which of the following is NOT a type of observational study?

• Cohort study

• Randomized controlled trial

• Case-control study

• Cross-sectional study

Why is it important to avoid bias in studies?

• To ensure the study is conducted quickly.

• To make the study more expensive.

• To ensure the results are valid and reliable.

• To reduce the sample size needed.

What does a census aim to achieve?

• Collect data from a random sample of the population.

• Collect data from every individual in the population.

• Predict future trends without current data.

• Observe and record behaviors without intervention.

In which type of study is the researcher most likely to interact with the subjects?

• Observational study

• Experimental study

• Census

• Sample survey

What is the purpose of using a sample in research?

• To save time and resources while still making inferences about the population.

• To collect data from every individual in the population.

• To increase the accuracy of the data collected.

• To ensure that the study can be completed within a day.

Which type of bias occurs when the method of data collection systematically excludes certain groups from the sample?

• Selection bias

• Response bias

• Measurement bias

• Time-lag bias