tag:blogger.com,1999:blog-21831384.post7962718699899857814..comments2019-10-03T14:11:35.530+05:30Comments on BzST | Business Analytics, Statistics, Teaching: Testing directional hypotheses: p-values can biteGalit Shmuelihttp://www.blogger.com/profile/06119270323184007583noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-21831384.post-14524346126593757672010-08-30T13:12:10.079+05:302010-08-30T13:12:10.079+05:30Ivan,
If you are very careful in specifying your n...Ivan,<br />If you are very careful in specifying your null hypothesis, then at least you will be testing the correct hypothesis. If your null hypothesis in a regression setting is beta=0 (i.e., non-directional), then indeed the p-values that the software yields is testing that hypothesis. If your null is directional and the resulting coefficient is statistically significant (according to the Galit Shmuelihttps://www.blogger.com/profile/06119270323184007583noreply@blogger.comtag:blogger.com,1999:blog-21831384.post-85154957554786447172010-08-30T13:07:34.087+05:302010-08-30T13:07:34.087+05:30Roxana - Sorry I missed your comment until now. Bu...Roxana - Sorry I missed your comment until now. But to respond to your question: While this problem with p-values is not a new issue, it has become much more prevalent due to the availability of large datasets. Most statistics textbooks (especially those written for the social sciences) were written in the mindset of too-little-data.<br /><br />Although confidence intervals can be used in place Galit Shmuelihttps://www.blogger.com/profile/06119270323184007583noreply@blogger.comtag:blogger.com,1999:blog-21831384.post-62567549600851402552010-08-30T09:58:02.876+05:302010-08-30T09:58:02.876+05:30could it be possible that for the regression case,...could it be possible that for the regression case, the none effect null hypothesis is tested checking the p-value and the "opposite directional effect null hypothesis is be check the sign of the Beta and the p-value? <br /><br />If the p-value is significant but the beta is negative instead of positive could that reject the opposite directional effect null hypothesis ?Unknownhttps://www.blogger.com/profile/10641912317913706491noreply@blogger.comtag:blogger.com,1999:blog-21831384.post-17906299480885383732009-12-09T03:04:30.778+05:302009-12-09T03:04:30.778+05:30How come other professors are not encouraging stud...How come other professors are not encouraging students to use the confidence interval instead of p-values when doing hypothesis testing? Is this a relatively new finding?Unknownhttps://www.blogger.com/profile/17463492988704864853noreply@blogger.comtag:blogger.com,1999:blog-21831384.post-26947947320291059912009-12-07T04:50:15.845+05:302009-12-07T04:50:15.845+05:30A confidence interval is not prone to the gap form...A confidence interval is not prone to the gap formed between statistical significance and practical significance, because you are forced to look at the magnitude of the coefficient. For instance, an interval such as (.1111111, .1111112) indicates that the population coefficient is most likely in this range. Whether this magnitude is meaningful or not depends on the application, but you can't Galit Shmuelihttps://www.blogger.com/profile/06119270323184007583noreply@blogger.comtag:blogger.com,1999:blog-21831384.post-15434268862297581722009-12-07T04:31:45.350+05:302009-12-07T04:31:45.350+05:30If you cringe at the thought/overuse of p-values d...If you cringe at the thought/overuse of p-values do you feel the same way about confidence intervals? Aren’t they compatible, or is the issue more that people are just more prone to the misuse of p-values but for some unexplained reason users properly reference confidence intervals?<br /><br />Elyas AkramElyas Akramhttps://www.blogger.com/profile/08776019011196147891noreply@blogger.com