P-ValueSee: Schneiter, K. (2008). Two Applets for Teaching Hypothesis Testing. Journal of Statistics Education. 16(3).
Use a p-value to make a decision about whether a coin is fair (i.e. the probability of tossing a head is 50%).
This tool consists of two 'views': the test view and the investigate view. The "Choose view" menu allows the user to move between them.
In each view, the p-value is displayed. In the test view, this enables the user to make a determination about whether or not the coin is fair, in the investigate view, the user can observe the behavior of the p-value when the probability of tossing heads with the coin is known. For a one-tailed test the p-value is the probability of getting the observed number of heads or fewer if the coin is fair. For a two-tailed test, the p-value is the probability that the absolute difference between the observed and expected numbers of heads is at least as big as observed, assuming the coin is fair.
In the test view, the probability of heads is initially unknown. You are asked to either "accept" or "reject" the hypothesis that the coin is fair. To guide your decision, gather information about the coin by tossing it. The applet displays the results of the tosses and the probability of getting the observed number of heads or something more extreme if the coin is fair (the p-value). The actual probability of tossing heads is revealed once the user has made a decision regarding whether or not the coin is fair.Top
Investigate viewUnder the investigate view, use the radio buttons to choose to flip a fair coin or a biased coin. The probability of tossing heads is displayed. Using the buttons to flip the coin, you can observe the results of the coin tosses under the indicated probability of tossing a head.