One to continue to contemplate....

Where that ACD thing fits ? -http://www.ixda.org/discuss.php?post=35466

I am not sure if such a distinction needs to be made, but if practitioners need clarification then....? An aspect that may be further validated and clarified through the literature review.

The concern at this point and my interest is in that if there is a need for such a distinction then the understanding I aim to provide of activities within the information ecology is an an argument for further justification of the work.

Some thoughts...
I would argue that ACD is more part of the evolution of UCD. Design is about framing problems, and ACD is more of an evolving perspective of UCD to frame problems.

I would agree with following view point made
On 11 Nov 2008, at 02:51, Livia Labate wrote: [snip]Dan Saffer differentiates ACS and UCS in his Designing for Interaction book very similarly/succinctly. His best point is that the PURPOSE of an activity is not necessarily a user goal, meaning looking at a design problem with a user goal in mind may be too esoteric and not necessarily helpful (which is the pro argument for ACD).[trim]

Fundamentally for me ACD for me draws on the principles framework set out in Activity theory and so for this reason I would argue that it is much more that a modern day task analysis to design. At its core activities consist of the tools people use, the subject the people themselves and the material object that can be tangible or totally intangible.

There are also several interesting point made by Josha Porter on the blog post
http://bokardo.com/archives/activity-centered-design/. A particularly interesting point is a point raised by Don Norman in the article ‘Human-Centered Design Considered Harmful’.Norman says:
“Many of the systems that have passed through HCD design phases and usability reviews are superb at the level of the static, individual display, but fail to support the sequential requirements of the underlying tasks and activities. The HCD methods tend to miss this aspect of behavior: Activity-centered methods focus upon it.”

To this I would ask how much of ACD and USD methods differentiate and overlap in design practice?