Evaluating the evidence: confidence intervals

Concepts

Introduction to the concept of confidence interval

Confidence intervals are fundamental for evaluating the evidence in any study. It is important to understand this concept and its interpretation.

How to interpret a confidence interval?

We discuss several examples that help in the interpretation of a confidence interval

Confidence intervals for probabilities and population means

Estimating risk in a biomedical context

Relative risk (RR) and Odds Ratios (OR) are important risk measures in epidemiology. Here, we define these indexes and show their interpretation.

Simulators

Estimating a probability

Comparison of methods for estimating the probability of an event from a sample. Through simulations, the results of several samples can be compared and the different aspects involved in estimating probability in the population can be discussed. The sample size is a key aspect.

Estimation of relative risk

Relative risk plays an important role in many medical situations. This application discusses its meaning and the procedure for estimating it from the data.

Odds Ratio Estimation

The concept of odds ratio as a measure of association is especially important in case-control studies. In this application you can explore its meaning and perform various calculations and simulations.

Estimation of population means

This application explores the concept of confidence interval in the estimation of the population mean and the difference of the means of two populations. Simulations are included to compare the results of different samples and the sample size needed for an accurate estimate is discussed.

Power and sample size

It is important to understand the concept of statistical power in relation to the sample size used. In this application, this problem is explored in connection with the concept of what the researcher wants to evaluate (effect size, equivalence of treatments, etc.).

Videos

IC of a probability

Sample size for estimating a probability

IC for the diference of a probability in two groups

Sample size for estimating the diference of a probability in two groups

Estimate the relative risc

IC for the mean of a population

Estimate the diference of a mean in two populations (1)

Estimate the diference of a mean in two populations (2)