Today was the first-ever instance of the new Blanton–Hogg combined group meeting. Chang-Hoon Hahn (NYU) presented work on the environmental dependence of galaxy populations in the PRIMUS data set and a referee report he is responding to. We discussed how the redshift incompleteness of the survey might depend on galaxy type. Vakili showed some preliminary results he has on machine-learning-based photometric redshifts. We encouraged him to go down the "feature selection" path to start; it would be great to know what SDSS catalog entries are most useful for predicting redshift! Sanderson presented issues she is having with building a hierarchical probabilistic model of the Milky Way satellite galaxies. She had issues with the completeness (omg, how many times have we had such issues at Camp Hogg!) but I hijacked the conversation onto the differences between binomial and Poisson likelihood functions. Her problem is very, very similar to that solved by Foreman-Mackey for exoplanets, but just with different functional forms for everything.
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