Editing 1574: Trouble for Science
Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.
The edit can be undone.
Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision | Your text | ||
Line 22: | Line 22: | ||
P-values are used in hypothesis testing. The p-value is the probability of observing an effect, result or relationship in your sample data, given that no such effect, result, or relationship exists in the population. It is based on the sample data and the particular statistic (such as sample average, t or F). A statistic is the result of a calculation based on the sample. A p-value can be calculated for each statistic of interest. Formally, the p-value is the probability of observing a test statistic equal to or greater than the one based on the sample data, given that the null hypothesis is true. | P-values are used in hypothesis testing. The p-value is the probability of observing an effect, result or relationship in your sample data, given that no such effect, result, or relationship exists in the population. It is based on the sample data and the particular statistic (such as sample average, t or F). A statistic is the result of a calculation based on the sample. A p-value can be calculated for each statistic of interest. Formally, the p-value is the probability of observing a test statistic equal to or greater than the one based on the sample data, given that the null hypothesis is true. | ||
− | The threshold for p-value cutoff, α, is pre-specified (usually 5% or 1%, which is more conservative). When the p-value is lower to or equal to α, the null hypothesis is rejected in favor of the alternative hypothesis. When it is higher than α, the null hypothesis is retained. | + | The threshold for p-value cutoff, α, is pre-specified (usually 5% or 1%, which is more conservative). When the p-value is lower to or equal to α, (that is, there is over a 1-⌠-1/∞ chance that the result was not coincidental due to a bad sample) the null hypothesis is rejected in favor of the alternative hypothesis. When it is higher than α, the null hypothesis is retained. |
The value used for ''α'' has been proposed by [http://web.lru.dk/sites/lru.dk/files/lru/docs/kap9/kapitel_9_126_On_the_origins.pdf Fisher] and is arbitrary. | The value used for ''α'' has been proposed by [http://web.lru.dk/sites/lru.dk/files/lru/docs/kap9/kapitel_9_126_On_the_origins.pdf Fisher] and is arbitrary. |