Dear R users, I wanted to test if there is significant difference between probabilities of the same event calculated in different ways. I am aware about the prop.test() which does the comparison between two proportions given the number of successes and sample sizes. But in my case the only values I do have are the probabilities the event. Your kind suggestions will be very appreciated. Mamuash
Equality of two probabilities (proportions?)
6 messages · mamuash bukana, Rolf Turner, Michael Dewey +1 more
On 10/02/17 21:12, mamuash bukana wrote:
Dear R users, I wanted to test if there is significant difference between probabilities of the same event calculated in different ways. I am aware about the prop.test() which does the comparison between two proportions given the number of successes and sample sizes. But in my case the only values I do have are the probabilities the event. Your kind suggestions will be very appreciated.
I think that it is pretty clear from your question that you are way out of your depth and that you do not understand the concept of "significant difference". You should therefore seek help from a competent local statistician. Although I could be wrong about my estimate of your depth of understanding, it is at the very least true that you need to read the posting guide carefully and learn how to ask a question that actually makes sense, includes necessary details, and gives list members a fighting chance of providing a meaningful answer. cheers, Rolf Turner
Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
Suppose we calculate probability of an event using Binomial distribution and got p1. Then probability of that same event is calculated using the Normal approximation to Binomial and got p2. Can't we evaluate the goodness of our approximation by comparing the difference between p1&p2? If yes, how to implement this in R? I wouldn't have been here seeking for help if I had that "deep" understanding of the issue under question Rolf! M
On Fri, Feb 10, 2017 at 10:42 AM, Rolf Turner <r.turner at auckland.ac.nz> wrote:
On 10/02/17 21:12, mamuash bukana wrote:
Dear R users, I wanted to test if there is significant difference between probabilities of the same event calculated in different ways. I am aware about the prop.test() which does the comparison between two proportions given the number of successes and sample sizes. But in my case the only values I do have are the probabilities the event. Your kind suggestions will be very appreciated.
I think that it is pretty clear from your question that you are way out of your depth and that you do not understand the concept of "significant difference". You should therefore seek help from a competent local statistician. Although I could be wrong about my estimate of your depth of understanding, it is at the very least true that you need to read the posting guide carefully and learn how to ask a question that actually makes sense, includes necessary details, and gives list members a fighting chance of providing a meaningful answer. cheers, Rolf Turner -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
Dear Mamuash I expect you will shortly get an email telling you that this is off-topic as it is about statistics not R but in the mean time you might search for "scoring rules" or even "Brier score". I am afraid I am not an expert in this area and they possibly do not answer your question but worth a try.
On 10/02/2017 11:27, mamuash bukana wrote:
Suppose we calculate probability of an event using Binomial distribution and got p1. Then probability of that same event is calculated using the Normal approximation to Binomial and got p2. Can't we evaluate the goodness of our approximation by comparing the difference between p1&p2? If yes, how to implement this in R? I wouldn't have been here seeking for help if I had that "deep" understanding of the issue under question Rolf! M On Fri, Feb 10, 2017 at 10:42 AM, Rolf Turner <r.turner at auckland.ac.nz> wrote:
On 10/02/17 21:12, mamuash bukana wrote:
Dear R users, I wanted to test if there is significant difference between probabilities of the same event calculated in different ways. I am aware about the prop.test() which does the comparison between two proportions given the number of successes and sample sizes. But in my case the only values I do have are the probabilities the event. Your kind suggestions will be very appreciated.
I think that it is pretty clear from your question that you are way out of your depth and that you do not understand the concept of "significant difference". You should therefore seek help from a competent local statistician. Although I could be wrong about my estimate of your depth of understanding, it is at the very least true that you need to read the posting guide carefully and learn how to ask a question that actually makes sense, includes necessary details, and gives list members a fighting chance of providing a meaningful answer. cheers, Rolf Turner -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
IMHO, You were given an appropriate answer. Please follow its advice. -- Bert Bert Gunter "The trouble with having an open mind is that people keep coming along and sticking things into it." -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
On Fri, Feb 10, 2017 at 3:27 AM, mamuash bukana <mamushbukana at gmail.com> wrote:
Suppose we calculate probability of an event using Binomial distribution and got p1. Then probability of that same event is calculated using the Normal approximation to Binomial and got p2. Can't we evaluate the goodness of our approximation by comparing the difference between p1&p2? If yes, how to implement this in R? I wouldn't have been here seeking for help if I had that "deep" understanding of the issue under question Rolf! M On Fri, Feb 10, 2017 at 10:42 AM, Rolf Turner <r.turner at auckland.ac.nz> wrote:
On 10/02/17 21:12, mamuash bukana wrote:
Dear R users, I wanted to test if there is significant difference between probabilities of the same event calculated in different ways. I am aware about the prop.test() which does the comparison between two proportions given the number of successes and sample sizes. But in my case the only values I do have are the probabilities the event. Your kind suggestions will be very appreciated.
I think that it is pretty clear from your question that you are way out of your depth and that you do not understand the concept of "significant difference". You should therefore seek help from a competent local statistician. Although I could be wrong about my estimate of your depth of understanding, it is at the very least true that you need to read the posting guide carefully and learn how to ask a question that actually makes sense, includes necessary details, and gives list members a fighting chance of providing a meaningful answer. cheers, Rolf Turner -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276
______________________________________________ R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
On 11/02/17 00:27, mamuash bukana wrote:
Suppose we calculate probability of an event using Binomial distribution and got p1. Then probability of that same event is calculated using the Normal approximation to Binomial and got p2. Can't we evaluate the goodness of our approximation by comparing the difference between p1&p2? If yes, how to implement this in R? I wouldn't have been here seeking for help if I had that "deep" understanding of the issue under question Rolf!
In your original post you asked about whether the difference was "statistically significant". As I suspected, the question is totally inappropriate. The concept of "statistical significance" does not apply in this context. There are no statistics; there are only calculations of probabilities. As I said, you are out of your depth and need to learn the basics of the subject that you are trying to deal with. Learn to walk before you try to run. There are no short cuts to an understanding of probability and statistics. A lot of hard graft is required. Michael Dewey's suggestion of studying "scoring rules" or the "Brier score" might be useful to you, but you need to get the basic principles of the subject (probability and statistics) straight in your mind before you dive into these ideas. As others have said, this issue is off topic for this list. cheers, Rolf Turner
Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276