Two-level fractional factorial designs are among the most useful statistical designs for engineering applications. This talk will review recent literature regarding the construction of these designs. Topics will include alternative criteria based on the alias length pattern, and uses of the row coincidence matrix to help distinguish between designs. A recently attempted complete enumeration of resolution IV designs for 128-run designs will be described. The talk will conclude with the open problem of how to search for optimal resolution IV designs for even larger run size.