How Designers Work: Making Sense of Authentic Cognitive Activity
Henrik Gedenryd’s 1998 PhD Thesis from Lund University.
One of the most valuable pieces of work on designing that I have encountered, and a good source for other key texts. Unfortunately Gedenryd died after completing this work, a very sad loss and I wonder where he might have taken his knowledge if he had lived.
Thesis Contents and Downloads (10 .pdf files)
Preliminaries
Title page, Contents and Acknowledgements
2. The Failure of Design methods
3. Design & Cognition as Inquiry
4. The Cognitive Roles of Action and the World
6. Making the World a Part of Cognition
7. Intermission (Conclusions)
Here’s a link to the location at archive.org where this is stored, unfortunately it’s a bit disorganised as archive.org does not help to distinguish between the different files in a publication so my chapter list above is the best way in.
Chris Rust's Blog 
19 April 2009 at 5:12 pm
Very nice webpage and helpful for Design students:)
27 September 2013 at 7:38 am
I stumbled upon Gedenryd’s dissertation back when I was doing my own PhD. It is a great read, well written and with a very coherent line of argument. I started looking for his work and then discovered that he had died shortly after completing this, and I share your sentiment – I’m sure that he could have enriched the field of design further.