1. Three Theorems Between Computability and Diophantine Approximation, presented during Dagstuhl Workshop, February, 2017. [ pdf ]
  2. The Mathematics of Relative Definablity, presented during the Joint Annual Meetings, Special AMS Session on Alan Turing, Boston, January, 2012. [ pdf ]
  3. Randomness and Recursion Theory, presented during Logic Colloquium 2010, Paris, France, July, 2010. [ 1, pdf ] [ 2, pdf ] [ 3, pdf ]
  4. Conservation Questions over BΣ2, presented during Reverse Mathematics: Foundations and Applications, University of Chicago, November, 2009. [ pdf ]
  5. Degree Invariant Functions, presented during VIG 2009, UCLA, November, 2009. [ pdf ]
  6. Undecidability of the α-degrees, jointly with Chong Chi Tat, presented during the workshop Topics in Computability: A Meeting in Honor of Richard A. Shore, MIT, January, 2007. [ pdf ]
  7. Moduli of Computation, jointly with Marcia Groszek, presented during the Conference on Logic, Computability and Randomness, Buenos Aires, Argentina, January, 2007. [ pdf ]
  8. Effective Randomness for Continuous Measures, jointly with Jan Reimann, presented during the workshop Effective Randomness, American Institute of Mathematics, Palo Alto, California, August, 2006. [ pdf ]
  9. Higher Orders of μ-Randomness, jointly with Jan Reimann, presented during the Dagstuhl Seminar Kolmogorov Complexity and Applications, Schloss Dagstuhl, Germany , January, 2006. [ pdf ]
  10. Turing Degrees and the Definability of the Turing Jump, presented to Computational Prospects of Infinity, Institute for Mathematical Sciences, Singapore, June 20 to August 15, 2005.
  11. Random Sequences and Recursive Measures, jointly with Jan Reimann, presented to CMS Winter Meeting, Special Session in Model Theory and Recursion Theory, Vancouver, Canada, December 7, 2003. [ pdf ]
  12. ``High'' is definable in the partial order of the Turing degrees of the recursively enumerable sets, presented to Conference in Honor of D. A. Martin's 60th Birthday, Berkeley, CA, May, 27, 2001. [ pdf ]
  13. On Martin's Conjecture, presented to AMS Meeting, Special Session in Set Theory, Las Vegas, NV, April 21, 2001. [ pdf ]
  14. Recursion Theory, presented as The Gödel Lecture, Annual Meeting of the ASL, Philadelphia, PA, March 13, 2001. [ pdf ]