Introduction
| What is statistical uncertainty? |
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| Statistical uncertainty is the uncertainty (present even in a representative sample) associated with the use of sample data to make statements about the wider population. |
| Why do we need measures of uncertainty? |
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| It usually is not feasible to include all individuals from a target population in a single study. For example, in a randomised controlled trial (RCT) of a new treatment for hypertension, it would not be possible to include all individuals with hypertension. Instead, a sample (a small subset of this population) is allocated to receive either the new or the standard treatment. |
| What are the measures of uncertainty? |
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| Either hypothesis tests (with the calculation of p values) or confidence intervals (CIs) can quantify the amount of statistical uncertainty present in a study, though CIs are usually preferred. |