- A complete Π
^{1}_{1}equivalence relation, work with D. Turetsky.

Workshop on computability theory, Prague, 2014. - Ordinal numbers and computability (a survey).

14th Midwest computability seminar, University of Chicago, 2014. - Admissible uncountable computable model theory (a survey).

Workshop on computable stability theory, American Institute of Mathematics, 2013. - Computing
*K*-trivial sets by incomplete random sets, work with L. Bienvenu, A. Kučera, A. Nies and D. Turetsky.

Computability in Europe, Milan, 2013. - Continuous higher randomness, work with L. Bienvenu and B. Monin.

2nd conference on Analysis, Randomness and Applications, Nancy, 2013. - Oberwolfach randomness and computing K-trivial sets, work with L. Bienvenu, A. Kučera, A. Nies and D. Turetsky.

Buenos Aires Semester in Computability, Complexity and Randomness, 2013. - Lowness in algorithmic randomness (a survey).

Dagstuhl seminar on Computability, Complexity and Randomness, 2012. - Strong jump-traceability (a survey).

12th Asian Logic Conference, Victoria University of Wellington, 2011. - Effective properties of uncountable linear orderings and other structures, work with A. Kach, J. Knight, S. Lempp and D. Turetsky.

12th Asian Logic Conference, Victoria University of Wellington, 2011. - Cupping and jump classes in the c.e. degrees, work with K.M. Ng and G. Wu.

4th Workshop on computability theory, University of San Francisco, 2011. - Strong jump traceability, Demuth randomness, and lowness, work with D. Turetsky.

6th conference on computability, complexity, and randomness, University of Cape Town, 2011. - Hyperarithmeticity through an algebraic lens, work with A. Montalbán and T. Slaman.

Seminar talk at Cornell University, 2010. - A new ideal of c.e. degrees, work with R. Downey.

Seminar talk at Cornell University, 2010. - SJT-hardness and pseudojump inversion, work with R. Downey.

5th conference on Logic, Computability and Randomness, University of Notre Dame, 2010. - Effective properties of uncountable linear orderings, work with A. Kach, S. Lempp and D. Turetsky.

Mal'tsev meeting, Novosibirsk, 2010. - Anticomplexity and reducibilities with tiny use, work with J. Franklin, F. Stephan and G. Wu.

53rd annual meeting of the Australian Mathematical Society, University of South Australia, 2009. - All SJT sets are
*K*-trivial.

4th conference on Logic, Computability and Randomness, International centre for mathematical meetings, Luminy, 2009. - C.e. SJT sets and benign cost functions, work with A. Nies.

3rd conference on Computability, Complexity and Randomness, Nanjing University, 2008. - Characterising classes of c.e. Turing degrees using strong reducibilities from above, work with G. Barmpalias and R. Downey.

Joint meeting of the AMS and the NZMS, Victoria University of Wellington, 2007. - Lowness properties of c.e. degrees, work with R. Downey.

Annual meeting of the ASL, University of Florida at Gainsville, 2007. - C.e. SJT degrees are a proper subideal of the
*K*-trivial degrees, work with P. Cholak and R. Downey.

2nd conference on Logic, Computability and Randomness, Buenos Aires, 2007. - Natural definability in the nether regions of the c.e. degrees, work with R. Downey.

Logic colloquium, Radboud University Nijmegen, 2006. - Antirandomness and near global hegemony, work with P. Cholak and J. Miller.

Seminar talk at Massey University, 2006. - Natural definability in the nether regions of the c.e. degrees, work with R. Downey.

Seminar talk at Victoria University of Wellington, 2006. - A computational prospect of infinity: ω
_{1}-recursion theory.

Program on computational prospects of infinity, Institute for mathematical sciences, National University of Singapore, 2005. - Ranks, derivatives, invariants, some reverse math: a study of an elephant, work with A. Montalbán.

Conference on Vaught's conjecture, University of Notre Dame, 2005. - Superatomic Boolean algebras and arithmetic transfinite recursion, work with A. Montalbán.

Joint meetings of the AMS, Atlanta, 2005. - Generalised high degrees have the complementation property, work with A. Montalbán and R. Shore.

Annual meeting of the ASL, University of Illinois at Chicago, 2003. - Lattice embeddings in the admissible r.e. degrees.

Annual meeting of the ASL, University of Las Vegas, 2002. - The elementary theory of the metarecursively enumerable degrees.

Greater Boston Logic Conference, MIT, 2001.