In a study that illustrates optional stopping, subjects tested paper strips in their saliva to see if they had a mildly serious medical condition. Some were told the test paper would eventually change color if they did have the condition, and some were told that it would eventually change color if they did not have the condition. The paper did not change for either group. The study found that:

The study found out that who were told that no color change in the paper indicated a bad sign kept waiting for a change of color in the paper before finally deciding that the test was over, they were also three times more likely to re-test the paper to be sure they got the right result. The other group who were told that the color change indicated that they did not have the condition stopped collecting evidence.

Explanation:

In actual reality, the paper given to them was ordinary paper so it was not likely to change color for any of the groups. the result however showed that those who thought a no color change indicated a serious medical condition were there times more likely to have a re-test and to wait longer to see if there was going to be a change in color, while those who were told that no change in color indicated no serious medication stopped collecting evidence. The result proved to show that when the evidence was going their way then they stopped collecting more evidence, however when the evidence seemed not to be going their way they kept on retesting trying to find more evidence to favor them.