Skip to main content

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: Simply way to calcuatle p value ? (Read 4162 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

Simply way to calcuatle p value ?

i undersand the improtna of p value and waht it represent. im just not good at getting the math right and everything i look up has it way overcomplicated for my little needs
So anyone that can help my with a simple way to calcuatle it for my A/B situations ?

In my test the issue is either True or false ( kinde like in ABX testing)
I want to  calcaulte thd P value for the results being true

aka let say 12 trials
trial 1  True
trial 1  Trues
trial 1  Trues
trial 1  False
trial 1  Trues
trial 1  False
trial 1  TRues
trial 1  TRues
trial 1  TRues
trial 1  TRues
trial 1  TRues
trial 1  TRues

aka 12 trials. ( 10 Trues. 2 False)

What is the simplest way to calculate the p value here? cutting out anything related to test done with other paramets



Sven Bent - Denmark

Re: Simply way to calcuatle p value ?

Reply #1
The "simplest way" is, arguably, to enter the figures into an online calculator: https://www.google.com/search?q=binomial+test+calculator
The null hypothesis of wild guessing would be a probability = 1/2 each time, since you have two alternatives A and B.  What you are looking for, is the chance of getting "such a wild result" as 10 or more, if the null hypothesis is true.

If you want to do it by hand: Then https://en.wikipedia.org/wiki/Binomial_distribution#Cumulative_distribution_function .
Rather than calculating up to 10, you can calculate "from 10 and up": since probabilities are 1/2 The chance of getting 10 or 11 or 12, equals the chance of getting 2 or 1 or 0. The probability of 1/2 simplifies p^k(1-p)^{n-k} to 1/2^n.