Special issue: Swan Delta 2019, the 12th Southern Hemisphere Conference on the Teaching and Learning of Undergraduate Mathematics and Statistics, Perth, Australia, 24-29 November 2019

This special edition comprises selected papers presented at the Swan DELTA 2019 conference, the twelfth Southern Hemisphere Conference on the Teaching and Learning of Undergraduate Mathematics and Statistics held in Fremantle, Australia, in November 2019. This is the eighth special edition of IJMEST to feature selected papers from the DELTA series of conferences, and as such, cements its role as one of the pre-eminent journals aimed at the dissemination of tertiary mathematics education research. The DELTA series of conferences continues to forge the valuable relationship between research and scholarship on current issues and practices in undergraduate mathematics education, supported by the IJMEST special editions that allow the participants to have truly international reach.