http://www.stat.cmu.edu/~kass/smnp/?p=94 Thu, 26 Apr 2012 14:07:02 +0000 hourly 1 http://wordpress.org/?v=3.0.4 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-151 Rob Rasmussen Tue, 28 Feb 2012 14:19:39 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-151 I really liked the example of the Poisson distribution and using the sample mean versus sample variance to estimate lambda. Is there any correlation between the sample mean and variance (minus their expected values), or are they independent random variables? I guess this would relate to the estimated Fano factor having variance from a sample of the Poisson distribution. I really liked the example of the Poisson distribution and using the sample mean versus sample variance to estimate lambda. Is there any correlation between the sample mean and variance (minus their expected values), or are they independent random variables? I guess this would relate to the estimated Fano factor having variance from a sample of the Poisson distribution.

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-150 Scott Kennedy Tue, 28 Feb 2012 14:10:30 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-150 Can we go over in detail the methods described in the SEF example? I'm confused about how the 'true' firing rate was calculated, as the spline fit and the PSTH are compared with this. Can we go over in detail the methods described in the SEF example? I’m confused about how the ‘true’ firing rate was calculated, as the spline fit and the PSTH are compared with this.

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-149 Yijuan Du Tue, 28 Feb 2012 13:47:28 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-149 Do we usually assume the estimator is unbiased in calculation and then check this assumption, similar as mentioned in last lecture? Do we usually assume the estimator is unbiased in calculation and then check this assumption, similar as mentioned in last lecture?

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-148 Matt Bauman Tue, 28 Feb 2012 12:44:32 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-148 I've heard about 'change point analysis before. Is that simply the systematic identification of these change points? And is a change point simply a value at which _any_ statistic changes? I’ve heard about ‘change point analysis before. Is that simply the systematic identification of these change points? And is a change point simply a value at which _any_ statistic changes?

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-147 Ben Dichter Tue, 28 Feb 2012 07:39:39 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-147 When it comes to bias vs. variance, how do you determine which is the problem and how do you correct the issue either way? When it comes to bias vs. variance, how do you determine which is the problem and how do you correct the issue either way?

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-146 Matt Panico Tue, 28 Feb 2012 06:41:43 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-146 You mention that real spike trains almost always differ from the Poisson assumption. A member of my lab keeps pushing for me to use the Poisson distribution in my analysis. How does this difference from Poisson usually look? You mention that real spike trains almost always differ from the Poisson assumption. A member of my lab keeps pushing for me to use the Poisson distribution in my analysis. How does this difference from Poisson usually look?

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-145 Rex Tien Tue, 28 Feb 2012 06:23:33 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-145 Is the weighted mean still a maximum likelihood estimator? Is the weighted mean still a maximum likelihood estimator?

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-144 Amanda Markey Tue, 28 Feb 2012 06:06:32 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-144 I did not follow the theorem on page 221-222. I did not follow the theorem on page 221-222.

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-143 Shubham Debnath Tue, 28 Feb 2012 06:05:10 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-143 Regression splines are mentioned as a smoothing method for comparing pseudo-data. What other methods are there, and what the benefits/downfalls for them? Regression splines are mentioned as a smoothing method for comparing pseudo-data. What other methods are there, and what the benefits/downfalls for them?

]]> http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-142 Sharlene Flesher Tue, 28 Feb 2012 04:47:03 +0000 http://www.stat.cmu.edu/~kass/smnp/?p=94#comment-142 Would there ever be a situation where it would be more useful to estimate lambda in a Poisson as the sample variance rather than the sample mean, as was discussed in the example in 8.1.1? Also, can you elaborate on the relationship between MSE and risk? Would there ever be a situation where it would be more useful to estimate lambda in a Poisson as the sample variance rather than the sample mean, as was discussed in the example in 8.1.1?
Also, can you elaborate on the relationship between MSE and risk?

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