Statistical power, G*power, Confidence intervals, sampling Flashcards
What is statistical power?
Statistical power is the probability of correctly rejecting a false null hypothesis. High power reduces the chance of a Type II error.
How can statistical power be increased?
Power can be increased by increasing the sample size, improving measurement precision, and increasing the effect size.
What is G*Power?
G*Power is a statistical software used to calculate the necessary sample size to achieve a desired level of statistical power for different types of analyses.
What are confidence intervals?
Confidence intervals provide a range within which the true population parameter is likely to fall. A 95% confidence interval means there is a 95% chance the true value lies within that range.
What factors affect the width of a confidence interval?
Sample size, variability in the data, and the confidence level selected all affect the width of a confidence interval. Larger samples produce narrower intervals.
What is random sampling?
Random sampling is a technique where every individual in the population has an equal chance of being selected for the study.
What is stratified sampling?
Stratified sampling divides the population into subgroups and randomly samples from each subgroup, ensuring representation across key variables.
What is convenience sampling?
Convenience sampling involves selecting participants who are easily accessible, though it may introduce bias.
Why is statistical power important in research?
Statistical power is important because it affects the likelihood of detecting a true effect and helps researchers design studies that are adequately powered to find meaningful results.
