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MT2 Extra Credit Opportunity

Hey guys,

An opportunity for you to help in the development of OpenBUGS and Brad decided to make it worth extra credit on problem 2 of the take-home midterm.

Extra Credit (worth up to 10% of the current total points available): re-fit your no-errors-in-covariates WinBUGS code using new OpenBUGS. Compare your point & interval estimates of the screening effect, as well as the fitted SMR maps. Are the answers equivalent up to Monte Carlo error?

Super Bonus Extra Credit: (also worth up to 10% of the current total points available): compare ESS and ES/second for WinBUGS and new OpenBUGS (see p.151 of the CL3 text). Is one program substantially more efficient than the other?

For more information, see the following motivating email from Neal Thomas:

"The latest version of OpenBUGS is now posted at www.openbugs.info. The Windows version come with an R-like installer. It is close to a first release version. We now have a group that has started work on the BRugs/R2WinBUGS packages.

A thorough checkout of the GeoBUGS features, distributions and graphics, would be very helpful. The only outstanding issue we know of is a discrepancy between WinBUGS 1.4.3 and OpenBUGS on the 'Shared' example (a WInBUGS/OpenBUGS comparison is posted on the wiki). We have not been able to sort this out yet but it arose when some (appropriate) constraints were placed on starting values and appears to be a WinBUGS rather than OpenBUGS issue. If you can encourage your students to make the testing reproducible, that would also be good, as it would be good to incorporate as much of it as is feasible in our routine testing in the future."