He is quite prolific and covers quite a range from programming UX through to experimental PL design practices and musical live coding. A few starting points:
Blackwell, A., Collins, N., 2005. The programming language as a musical instrument. Proceedings of PPIG05 (Psychology of Programming Interest Group) 3, 284–289.
Blackwell, A., Green, T., 2003. Notational systems–the cognitive dimensions of notations framework. HCI Models, Theories, and Frameworks: Toward an Interdisciplinary Science. Morgan Kaufmann.
Blackwell, A.F., 2006a. Ten years of cognitive dimensions in visual languages and computing. Journal of Visual Languages and Computing 4, 285–287.
Blackwell, A.F., 2006b. The reification of metaphor as a design tool. ACM Transactions on Computer-Human Interaction (TOCHI) 13, 490–530.
Blackwell, A.F., Church, L., Green, T.R.G., 2008. The abstract is’ an enemy’: Alternative perspectives to computational thinking, in: Proceedings PPIG. pp. 34–43.