A popular and very useful textbook in Interaction Design defines the field with this diagram: 
As I explain in the Introduction and especially in Chapter 2, Inventing the Medium is not meant to substitute for the body of knowledge mapped above but to complement and recontextualize it, by drawing on disciplinary methods and craft practices that are absent from the HCI/Interaction Design map of the design process.
Here is how I would express it, using the same diagram:
The humanistic perspective does not exclude or compete with the other disciplines and design practices: it reframes them as elements in the shared enterprise of inventing a new medium of representation.
Nice story on Interaction Design as a Cultural Practice. I would like to thank you for this.