Estimating Sample Size

What is the primary purpose of calculating sample size in research studies?

• To determine the number of variables to include in the analysis

• To estimate the population parameters with precision

• To control for random error in data collection

• To increase the statistical power of the study

Which factors typically influence the calculation of sample size in a research study?

• Effect size, confidence level, and power

• Standard deviation, significance level, and sample variability

• Type I error rate, sample proportion, and population size

• Random error, standard error, and hypothesis testing

How does increasing the desired confidence level affect the required sample size?

• It decreases the required sample size

• It increases the required sample size.

• It has no effect on the required sample size

• It depends on the effect size of the study.

What role does the effect size play in determining the sample size for a study?

• Larger effect sizes require smaller sample sizes

• Larger effect sizes require larger sample sizes

• Effect size is unrelated to sample size calculations.

• Effect size affects the confidence level, not the sample size.

In a study with a fixed effect size and significance level, how does increasing the power of the study impact the required sample size?

• It decreases the required sample size.

• It increases the required sample size.

• It has no effect on the required sample size.

• It depends on the effect size and significance level.

Which statistical concept is directly related to the precision of sample size calculations?

• Standard deviation

• Standard error

• Confidence interval

• Type I error rate

When conducting a hypothesis test, how does reducing the allowable margin of error influence the required sample size?

• It decreases the required sample size.

• It increases the required sample size.

• It has no effect on the required sample size.

• It depends on the effect size of the study.

In a survey study with a 95% confidence level, what is typically chosen as the desired margin of error?

• ±1%
  

• ±5%

• ±10%

• ±15%

What does the term "power" refer to in the context of sample size calculations?

• The ability to detect a true effect when it exists

• The probability of making a Type I error

• The precision of the sample estimate

• The variability of the sample data