Present: Lee, Tom, Daniel (scribe), Kwaku.

Administrative

• Jake may come and bring brevis into the group
• Several people are expressing intrest to join the group in the near future

Future Work

• GPTP chapter deadline is 5/30
  • needs update for new data
• Add Jamie and Daniel’s data to lexicase article
• GPTP token to Tom
• Lexicase and node selection are next for Tom
• Discussion of what Daniel should be doing
  • weighted lexicase with previous algebra work
  • try to do push work with environments
  • do push for finite algrebra problems

GPSP

• Lee has been communicating with Alberto Moraglio
• Alberto has been learning Push and Clojure very quickly
• He has been working on a system he thinks could solve a very difficult parity challenge
  • Anyone is welcome to help work on this

Selection

• Lexicase selection seems to be demonstrably good in many cases
• It is even good in non modal problems
• Have looked at ways to improve lexicase selection
• All previous attempts at improving lexicase have been bad

Niche Elite Selection

• This is the system talked about in the previous meeting
• This system seems to be truly terrible

Newest Proposed System

• Instead of doing sorting of cases, sometimes can skip a case
• Discussion when and why you skip
  • Decide want a low chance of skipping if case is unique
  • This calls for a similarity measure; we decide to use mutual information
  • Kwaku brings up this is a valuable metric about test cases in general
• Decide the specialness of cases shouldn’t be recomputed for smaller populations

Reading

• There will be a discussion next meeting about the genetic improvement paper that has already been sent out to the list