For the interested.
From Frederick P. Brooks, jr.'s book 'The Design of Design', chapter 17:


"Progressive truthfulness

Good design is top-down. One starts a prose document with an outline that identifies the key ideas and then the subordinate ones. One begins a program by thinking about a data structure and an algorithm. One starts thinking about a house plan by identifying the functional spaces based on the use cases, and then their connectivity. One early on adresses a building's esthethics in terms of massing.
Great designers, even the most iconoclastic, rarely start from scratch -they build on the rich inheritance from their predecessors. They take an idea from here, an idea from there, add some of their own, and wrestle the mix into a design that has conceptual integrity and a coherent style of its own.
The usual technique is to begin a design with predecential idas but blank paper. One scetches in the big units and then proceeds by progressive refinement, adjusting dimensions and adding more and more detail.
Turner Whitted in 1986 proposed that another, perhaps better, way to build models of physical objects (originally in the context of computer graphics) is to start with a model that is fully detailed but only resembles what is wanted. Then, one adjusts one attribute after another, bringing the result ever closer to the mental vision of the new creation, or to the real properties of the real-world object.
Whitted called this technique progressive truthfulness. In a very real sense, progressive truthfulness is precisely the program of the natural sciences over the past few centuries, as their models approach the existing natural creation.
With human design of artifacts, the very process of designing occasions changes in the mental ideal that the design approaches. Progressive truthfulness radically helps. One has at every step a prototype to study. The prototype is initially valid; that is, there are no inconsistencies in structure. The prototype is always fully detailed, so that visual and aural perceptions of it do not mislead. (...)


Hazard of the progressive truthfulnessis mode

Although I postulate that progressive truthfulness is how the most productive and easy-to-use design systems must be built, it has its inherent hazards.
Some will argue that broad exposure to exemplars will implicitly limit the designer's creativity. Could the designs of a Brunelleschi, a le Corbusier, a Gehry, a Gaudi, emerge from the mind of designers so indoctrinated?
I submit that they did. None were amateurs. All trained by studying precedents. Like Bach, they innovated from mastery, not ignorance. The Grandma Moseses of the world are few.
Perhaps more relevant, these "but what about?" examples represent a minute fraction of designs, and a great tool doesn't have to provide for discontinuities.
The true hazard of progressive truthfulness lurk in the library. Bad models, too few models, too narrow a variety of models -these shortcomings will most limit the emerging designs. This hazard will be worst at the beginning."


The rest of the chapter actually goes into to the concept of transcription from NPR to PMR, as its next headline says, "A vision for Input from Mind to Machine". And in the intro: "Whether designing from an exemplar or de novo, how does one transform thought-stuff into a computer model?
One wants to utter one's castle in the air into existence, using the voice, both hands, the head, and conceivably the feet.(...)"
But the rest deals with specific computer model solutions concerning the usability of pc operation system and architectural house-designing programs. and quite cryptic to me.

-kristian

This is very interesting, thank you kristian. Top down being more profitable has popped up recently somewhere else too.
Love
Bette

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All That Is
what is?
Consciousness.

Thanks Kristian for that,

Top-down modeling does have an advantage in that it facilitates fabrication of a preconceived notion. As long as the notion serves the need of the moment, that is fine.

But all models suggest, if not outright imply, that they cover the turf they are intended to; they may not.

Still it is a great left-brained discipline to follow... taking a model of something and refining it till you think you have everything covered, every attribute accountable in a mathematical sense.

It's pesky though that reality appears to have evolved from the bottom up.


-Montana

hm.. reality itself? Are you settled on that notion?

Yes, if you accept the MBT model. Reality as Consciousness Space arose from the random data within the reality cells starting from the Void state via random interactions and the evolutionary principle. Can't get more 'bottom' than that in a sense. It was not however a conscious process for a very long 'time'. The VRs however begin sort of from the whole of the middle as probability and pick up the extremes when someone is capable of observing them. How the CS developed the concept of the VRs, top down or bottom up, is an open question.

Ted

But wouldn't you (shouldn't you) still discriminate between the process and the existence of the process?

Isn't the existence of the initial random data and consequentially the system of progressive fractal information-evolution, in itself, as compared to nothing, (the existence of the possibility of illusions), even in MBT model, remainingly unexplained? Thus reality as consciousness experience, not as consciousness experience process-model, will not unbiased appear as either bottom-up or top-down.
At least not currently to this character.

It is pesky though how it appears to appear as it appears.

-kristian

Beginnings are a pesky thing. I'm not sure how you can do anything but start from the bottom up when you have "nothing" (void state) to begin with.

"Great designers, even the most iconoclastic, rarely start from scratch -they build on the rich inheritance from their predecessors."

Once you have something to build upon, sure. That's what evolution is all about.



I'm not 100% sure what you mean but, yes, that is basically the 2 assumptions presented by MBT.

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Mike

hi,


That is the assumption I judged to be wrong. from nothing doesn't imply bottom-up, was my understanding. It could be faulty to explain the possibility of information to exist or come into existence as a selftriggered cause, rather than a given. They are equally illogical.

if you with 'void state' imply random data, then you have a given system already. that system evolves bottom-up, evidently, but it doesn't come into existence by itself. It didn't come in to existence bottom-up. Not logically. But there is the possibility to imagine logic itself as illogical. I guess that's where one lets go?

-kristian

Kristian,

But that is the way that we understand the Consciousness System to have originated. In the MBT model, there is nothing before and nothing that designed the CS, certainly not that we can know of. It started from nothing and simply had the inherent properties (reality cells and the evolutionary principle) to create consciousness as a potential inherent property. Once the very beginnings came to be, the development was self induced and self directed, the bootstrapping. The potential for the interactions of reality cells and their contents was inherent and not created. Logic did not pre exist consciousness but was created in the bootstrapping process leading up to the first dim consciousness. Otherwise you are back to saying that there was a 'god' who created the set of conditions which became the CS. That is not necessary as the two assumptions that Tom makes are adequate within themselves. But they must remain assumptions as we, as creatures of Consciousness, have no access to the Ur-stuff of the absolute base level that generates consciousness and within which it (and we) exists as information.

Ted

this top down vs bottom up concept reminds me of discussions on the Asian approach to engineering vs the American approach - below reflects my internal prejudice on this subject...so I welcome push back and apologize if anyone is offended

put a group of (multiracial) American-based engineers in a room with a problem, and they will start building and testing models and failing...like Edison would say..."one more thing we know doesn't work"

put a group of Asian-based engineers in a room and they will start discussing authorities and planning meeting scheduling, or the big boss will dictate the method to be followed.

by the time the Asian team has sorted out who's in charge of the project, the Americans will have tested 1000 theories and destroyed 1000 models and found the needle in the haystack that works (or maybe some guy in a garage finds it), then the Asian team will copy it, which they are profoundly skilled at

oh...Tom is the guy in the garage for physics!

this has been my personal science-based approach to spirituality - try everything...see what works

that trying everything process involves a lot of blowing things up....downward facing dog pose anyone...anyone? Beuller? Beuller?

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Does this PMR make my butt look big?

Thanks. That is the way we accept not to understand it, would be a fair rephrasing. I suspect I am close to my ego's comfort zone here. thank you, still. You made me get the book out and it took about 15 seconds to find chapter 18 where he goes into detail on this issue, and I could recover some humility, (would be a fair phrasing).

-beuller!

kristian