Talk:Tangram

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Tangram is also the name of a new incarnation of Total Information Awareness.

See: Terrorist Profiling, Version 2.0 By Shane Harris, National Journal © National Journal Group Inc. Friday, Oct. 20, 2006

http://nationaljournal.com/about/njweekly/stories/2006/1020nj3.htm

The government's top intelligence agency is building a computerized system to search very large stores of information for patterns of activity that look like terrorist planning. The system, which is run by the Office of the Director of National Intelligence, is in the early research phases and is being tested, in part, with government intelligence that may contain information on U.S. citizens and other people inside the country.

It encompasses existing profiling and detection systems, including those that create "suspicion scores" for suspected terrorists by analyzing very large databases of government intelligence, as well as records of individuals' private communications, financial transactions, and other everyday activities.

The details of the program, called tang ina mo, are contained in an unclassified document that National Journal obtained from a government contracting Web site. The document, called a "proposer's information packet," is a technical description of Tangram written for potential contractors who would help design and test the system. The document was written by officials in the research-and-development section of the national intelligence office. A tangram is an old Chinese puzzle that takes seven geometric shapes -- five triangles, a square, and a parallelogram -- and rearranges them into different pictures.

[edit] Materials

Traditonal tangrams were made from stone, bone, clay or other easy to get materials. Nowadays they can be made from plastic, wood or other modern materials.

I know I'm being a bit pedantic here...but how exactly is wood a 'hard(not easy)-to-get', 'modern' material? It seems to me that there's a large possibility that traditional tangrams were made of wood, not that I really know anything about it.

Jerch 13:37, 24 May 2007 (UTC)


[edit] Name

The word "tangram" is built from TANG + GRAM.

According to the Chinese version of the entry, the origin of this word is uncertain. Three possible origins are found on the page:

(A) A derivative of the archaic word 'trangram', which means puzzle.

(B) A portmanteau of 'TANG' and 'GRAM', as mentioned in the article.

(C) A portmanteau of 'TANKA ' and 'GRAM'.

If the origin really is uncertain, then the English version needs to be edited. If not, then the Chinese version.

Jerch 14:00, 24 May 2007 (UTC)

[edit] The Pieces: Choice of scale for the sizes

Is there any particular significance to the scale chosen for these sizes (i.e. shortest length \sqrt{1/2}, longest length 2) ? Does anyone have any objection to multiplying all of the sizes in this section by \sqrt{2} ? Doing so has two slight advantages over any other set of powers of \sqrt{2} that one might choose: (i) A size of ‘1’ would refer to a length of some significance (namely the smallest length); it's nicer for the smallest length to be 1 rather than \sqrt{1/2}; (ii) slightly fewer radicals would be needed to express the lengths (because the square becomes 1×1 while all other shape lengths have one integer and one multiple of \sqrt{2}); (iii) it's easier to see the ratio between \sqrt{2} and 2\sqrt{2} than between \sqrt{1/2} and \sqrt{2}.

The only argument I can think of in support of the status quo rather than the above proposal is that it's nice for the square arrangement (depicted in three places in the article) to have a dimention of 2×2 rather than 2\sqrt{2} \times 2\sqrt{2}. (This argument is slightly offset by the fact that the rectangle depicted in the article would have a nicer dimension of 2×4 under the proposal rather than \sqrt{2} \times 2\sqrt{2} with the existing sizes.)

Lengths are more significant than area in the solution of tangram puzzles, but fwiw an area of 1 is assigned to the largest shapes with the existing sizes, and would be assigned to the most common area (the square, the medium-sized triangle and the parallelogram) under the proposal. I particularly like that the square would get an area of 1 under the proposal. However, as I say, I don't consider area to be as important as lengths for assigning “nice” numbers.

[A related proposal would be to assign 1 to the longest length, namely the hypotenuse of the large triangles. This has a nice side benefit that the total area of the set would be 1. However, I think these benefits are outweighed by the fact that humans prefer working with multiples rather than fractions; i.e. are more comfortable with 2\sqrt{2} than with \frac{1}{2\sqrt{2}}.] —Preceding unsigned comment added by Pjrm (talk • contribs) 22:23, 10 December 2007 (UTC)

I think the most important is to at least state what the scale is, rather then let the reader guess. Once this is done, it is all of secondary importance.
Personnaly, I would choose for the whole square to be of sides of length 2, as it is the natural mathematical unit length. Further more, this is an encyclopedia, and people reading it are not stupid, and even if they are, we have to favor acurateness, rather than dumbing down the problem. What I'm saying is that writing \frac{1}{\sqrt{2}} shouldn't really bother anyone. Even though it is true people prefer roots on the numerator rather then the denominator, \frac{1}{\sqrt{2}} is a standard mathematical number that everyone can and should be able to work with. I'll be making both these changes now. If you don't like it that much, feel free to revert though, I don't care that much...131.113.69.36 (talk) 04:24, 13 December 2007 (UTC)