A Little Bayes

Thomas Bayes (1701 - 1761) was an English mathematician, philosopher, and Presbyterian minister who developed a new way of thinking about data and probability.
His central concept: We update our knowledge as data are collected.
Data may be observations or measurements of the natural world or may be collected during an experiment.
The white box below is a simple region in which to illustrate Bayes' theorem. Your task is to use data to locate a small triangle is hidden somewhere within the white box.
This process is a simple model of how we gain confidence in our knowledge of the natural world.
Initially the white box is empty. You have no information about the position of the hidden triangle.
Click inside the white box to place an orange dot, marking your guess about the location of the hidden triangle.
Click the Measure button below to make a measurement of the hidden triangle. As a result...

Clicking inside the white box after a measurement updates your idea of the hidden triangle's location.
Click the Measure button as many times as you wish and update your idea of the triangle's location, based on the measurements, as many times as you wish.
Click the Reveal button to display the triangle's true location.
Click the Restart button to begin a new search for the triangle at a new location.

A Demonstration of Bayes' Theorem