HESC 401 Chapter Notes - Chapter 5: False Positives And False Negatives, Unimodality, Blood Pressure
Document Summary
To define the validity and reliability of screening and diagnostic tests. To compare measures of validity, including sensitivity and specificity. To illustrate the use of multiple tests (sequential and simultaneous testing). To introduce positive and negative predictive value. To compare measures of reliability, including percent agreement and kappa. Bimodal curve: a data curve in which two different peaks occur in the data: a bimodal curve allows one to easily separate two groups because it clearly shows two distinct patterns in data. However, human characteristics are often dispersed in a unimodal fashion: a single peak in data: thus, it is more difficult to make clear distinctions in the data, example: blood pressure. There is no obvious level in which people are considered hypertensive or normotensive since blood pressure levels are dispersed fairly widely. In both unimodal and bimodal curves, outliers are easy to spot; these represent abnormal values: where there is uncertainty is the gray zone; data between the outliers.
