Author Topic: Categorizing and Organizing Knots for Reference  (Read 2703 times)

adalew

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Categorizing and Organizing Knots for Reference
« on: January 27, 2015, 03:32:14 AM »
Hi All,

I'm a grad student at the University of Washington, Seattle (USA), studying Information Management. I am curious to know if there is any knot classification schema--some method of organizing knots so they are easy to look up and refer to. I've seen use of ABOK #xxxx as a common reference point. Are there any other systems like that?

Are there common knot categories that can be applied to various knots?

It seems like some possible categories may be:

1) Type of knot: hitch, bend, loop, shank...

2) Context: sailing, fishing, hiking, climbing, decorative...
 
3) Difficulty (or perhaps speed)

4) Employment: rope-to-rope, rope-to-thing, rope-to-thing+loop, rope-to-rope+loop, tighten, brace/hold, net...

5) Name: preferred term, related term...

6) Cultural origin

7) Defined by # of crosses?


I don't have much knowledge in the knot world, that's why I check-in with you all for help. :)

I assume this has probably been asked before, and I apologize for my lack of knowledge. I searched through the forum posts, but didn't find answers to this question specifically.

If one was given a type of knot, for example a Bowline, would it be possible to fill in information in the categories mentioned above?

Also, does that seem useful or practical?

Thanks all for your help! Please feel free to contact me directly if you'd like.

-Adam



 

xarax

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Re: Categorizing and Organizing Knots for Reference
« Reply #1 on: January 27, 2015, 10:38:14 PM »
    There are a few, only, things that are "common" in the world of knots, so it is no surprize that "knot categories" is not one of them. 
    I would only like to notice two things :

1. Your category#2 contains the term "decorative". Although the distinction between "Practical" and "Decorative" knots can not be defined as unambiguously as many people believe or wish, nevertheless it is fundamental, and runs across the whole field of knotting. On the other hand, considering that almost any sufficiently convoluted tangle of rope(s) would be able to "do the job" ( friction is such a kind to us property of materials... ), how a knot "looks", i.e. its symmetries, "simplicity", elegance, silhouette, etc., always plays a major role in our decision to learn it, remember it, improve our dexterity and speed in tying it, and finally use it - so practical knots are often judged according to values which seem to belong to the sphere of aesthetics, and characterize decorative knots.

2. Your category#7 should be stated differently. Practical knots are not "defined" by the (minimum) number of crossings, because topology does not determine geometry uniquely : we have many cases where very different, geometrically and mechanically, knots, share the same topology, hence they have not only the same number of crossings, but also the same 2D representations / diagrams.

   We can add many more "categories", some of which may be useful when we select a particular knot for a particular material and a particular task, and some may be useful only for "taxonomical" purposes. Easiness of tying and untying, required rope length, resistance to various patterns of loading, area of cross section along the axis of the knot, etc.
   
« Last Edit: January 27, 2015, 10:39:33 PM by xarax »
This is not a knot.

roo

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Re: Categorizing and Organizing Knots for Reference
« Reply #2 on: January 28, 2015, 12:49:24 AM »
Hi All,

I'm a grad student at the University of Washington, Seattle (USA), studying Information Management. I am curious to know if there is any knot classification schema--some method of organizing knots so they are easy to look up and refer to. I've seen use of ABOK #xxxx as a common reference point. Are there any other systems like that?

Are there common knot categories that can be applied to various knots?

It seems like some possible categories may be:

1) Type of knot: hitch, bend, loop, shank...

2) Context: sailing, fishing, hiking, climbing, decorative...
 
3) Difficulty (or perhaps speed)

4) Employment: rope-to-rope, rope-to-thing, rope-to-thing+loop, rope-to-rope+loop, tighten, brace/hold, net...

5) Name: preferred term, related term...

6) Cultural origin

7) Defined by # of crosses?


I don't have much knowledge in the knot world, that's why I check-in with you all for help. :)

I assume this has probably been asked before, and I apologize for my lack of knowledge. I searched through the forum posts, but didn't find answers to this question specifically.

If one was given a type of knot, for example a Bowline, would it be possible to fill in information in the categories mentioned above?

Also, does that seem useful or practical?

Thanks all for your help! Please feel free to contact me directly if you'd like.

-Adam

For the small group of the most used knots, names usually suffice and are fairly easy to use.  Classifications such as hitch, bend, noose and loop are often integrated into the name, but other similar classifications such as tensioner and ascender usually get left out of names.

As you expand your circle out to less common knots, ABOK numbers and other publication references do help.  Diagrams sometimes have to be used, and if posted online, become just another publication reference, but it doesn't do much for easy look-up short of some image recognition software.

As you keep expanding out the circle to include millions of knots, things get hairy, as you might expect.  The boundaries of related knots and how they are applied and dressed compounds the problem.  The drive for this extreme level of classification tends to lose steam as the use for it doesn't justify the effort.
« Last Edit: January 28, 2015, 12:53:37 AM by roo »
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Wed

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Re: Categorizing and Organizing Knots for Reference
« Reply #3 on: January 28, 2015, 01:10:17 AM »
Once you get outside English. Things will be really ... interesting (read complicated).

adalew

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Re: Categorizing and Organizing Knots for Reference
« Reply #4 on: January 28, 2015, 08:28:46 AM »
Thanks for your replies, they are very helpful! :)

Quote
The drive for this extreme level of classification tends to lose steam as the use for it doesn't justify the effort.

I understand what you mean about diminishing returns. It'd be a monumental (and very complicated) task to organize all known knots! It's a very interesting knowledge-as-process type of problem-- classifying "things" that are actually a series of specific steps. I wonder if it's possible to break knots down into sets of steps--similar to radicals for East Asian written characters?

Quote
...names usually suffice and are fairly easy to use.  Classifications such as hitch, bend, noose and loop are often integrated into the name...

This is true among people who are at least somewhat familiar with knots, but I'd venture that many, many people aren't familiar with knot names, what even the most common ones are used for, or understand terms like hitch and bend. I guess that is where we will probably focus. For example, say a person needs to tie a canoe to the top of their car, it's very possible that person would not know the name or type of knot to look up. It's something that we may focus on.

Xarax, thanks for the help. We've decided to remove any idea of counting crossings, bends, etc...as you say these can't really be defined in 3D space for object with no necessary orientation.

Quote
...the distinction between "Practical" and "Decorative" knots can not be defined as unambiguously as many people believe or wish...

Very true, it's certainly subjective. I think the best we can do categorize based on our user's responses. We'll likely use a service called OptimalSort to help us understand what experienced and inexperienced people think, and try to join it all together.

Quote
Once you get outside English. Things will be really ... interesting (read complicated).

Oh, man. I can't imagine. I bet, however, that it can be very illuminating to know the name of a knot in different languages. I lived abroad (outside the USA) for 10 years, mostly in Europe & East Asia and it could be awesomely mind-blowing and entertaining to learn how things are labeled in other languages (like "electric brain" for computer in Chinese)...not to mention concepts...




xarax

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Re: Categorizing and Organizing Knots for Reference
« Reply #5 on: January 28, 2015, 12:56:25 PM »
   I wonder if it's possible to break knots down into sets of steps--similar to radicals for East Asian written characters ?

   I am not aware of any such attempts, to "break down" the tying procedures of knots into sequences of separate, successive "steps" - which may mean, a: successive "gestures" by which we have to manipulate the Working Ends, in order to set up the knot, or, b: separate parts of knots, which, when joined / combined, the one after the other, form the whole knot.
   For something close to b, see :
   The basic elements of any practical knot
   http://igkt.net/sm/index.php?topic=2191.0
   Derek Smith has also "analysed" knots into separate "elements" - better ask him directly to tell you more about his scheme.     

..these can't really be defined in 3D space for object with no necessary orientation.

   I have tried to explain what I mean, at :
   http://igkt.net/sm/index.php?topic=4201

   Topologically identical knots, with the same number of crossings, can have more than one stable 3D forms, so they can differ, in the way they "work", as rope mechanisms, a lot. We may need some time until we realize that the one can be transformed into the other - an example is Scott s TIB bowline and Ampersand TIB bowline. :
   http://igkt.net/sm/index.php?topic=4877.msg31925#msg31925

« Last Edit: January 28, 2015, 12:57:07 PM by xarax »
This is not a knot.

Wed

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Re: Categorizing and Organizing Knots for Reference
« Reply #6 on: January 28, 2015, 03:07:32 PM »
Harry Asher tried to introduce steps to tie knots in his book "The Alternative Knot Book", ISBN-10: 0911378952, ISBN-13: 978-0911378955.

adalew

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Re: Categorizing and Organizing Knots for Reference
« Reply #7 on: January 29, 2015, 10:08:40 AM »
Thanks for your responses. It seems like many have tried, but it gets complicated fast. Like language, there are so many exceptions to the rules, possibilities, and variations, the key element is really usage (at least within a group). The English language has over 1 million words, but it would be a mistake for a non-native speaker to learn by opening an unabridged dictionary and start memorizing words, even if able to pronounce all of the syllables.

In order to better understand knots as they are used by people who speak knot (you guys), my group is hoping the members of this forum could help. ;) 

We've put together 2 preliminary card sorts. A card sort just means dragging little cards--each with a knot name or picture--and dropping them into a group/category. It's pretty intuitive.

In the first card sort, we ask that you drag a knot photo into 1 of 3 skill levels. It will probably take ~5 minutes. Here is the link:
https://4i5665b4.optimalworkshop.com/optimalsort/3b8ykrv5

In the second card sort, we ask that you move knot names into various categories or make your own. It requires familiarity with some common knots by name and will probably take ~10 minutes. Here is the link:
https://4i5665b4.optimalworkshop.com/optimalsort/30f3278i

They are both completely anonymous and no personal info is taken or required. If possible, please recruit other members to try the card sorts! It seems like it an entertaining way to brush up on some knot recognition. :)

Thanks to you all for your help!

 




preventec47

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Re: Categorizing and Organizing Knots for Reference
« Reply #8 on: March 20, 2015, 10:27:10 PM »
I have several books on knots and have several bookmarks for
internet websites that list and explain how to tie many knots
but the single super important ingredient missing in all of them
is a specific rating as to how easy the knot is to untie after having
been pulled hard.   I guess the name for it is JAM or JAMABILITY
but there needs to be a number rating not just a subjective
"adjective".  Of course strength of the knot compared to the strength of the untied rope is important.   The difficulty factor
could be listed but usually just looking at the diagrams showing
how to tie gives an immediate clue to how complicated it is and
whether it can be committed to memory.

Sweeney

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Re: Categorizing and Organizing Knots for Reference
« Reply #9 on: March 20, 2015, 10:41:16 PM »
I have several books on knots and have several bookmarks for
internet websites that list and explain how to tie many knots
but the single super important ingredient missing in all of them
is a specific rating as to how easy the knot is to untie after having
been pulled hard.   I guess the name for it is JAM or JAMABILITY
but there needs to be a number rating not just a subjective
"adjective".  Of course strength of the knot compared to the strength of the untied rope is important.   The difficulty factor
could be listed but usually just looking at the diagrams showing
how to tie gives an immediate clue to how complicated it is and
whether it can be committed to memory.

This sounds good in theory but consider the Bowline as an extreme example - tied in rope it is easy to undo and will not jam. But tied as the "Canoe Man Knot" in fishing line and it will be all but impossible to see let alone untie. It really does depend on the material as well as the loading necessary to cause a jam. I use the Perfection Loop regularly and find it reasonably easy to untie but I don't get anywhere near the breaking load of the rope/cord and clearly not enough to jam it tight as it is reputed to do. Maybe it is possible to design a grid showing for different materials the "jammability" of different knots but you would also have to standardise the load factor somehow - I am not convinced the result would help much.

Barry

preventec47

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Re: Categorizing and Organizing Knots for Reference
« Reply #10 on: March 20, 2015, 10:57:31 PM »
It seems to me that the "relative" anti-jamability in comparison
to all other knots would remain the same regardless of the
type of cord or rope used and if true then the chart would not
need to contain info for different types of ropes.  Simply a statement
can be made that some rope materials like fishing line are not going
to allow for a knot to be untied no matter what.

SS369

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Re: Categorizing and Organizing Knots for Reference
« Reply #11 on: March 20, 2015, 11:46:01 PM »
Hi preventec47.

I definitely don't agree with you concerning the statement that different types of cord/rope don't influence the jamming or untie-ability. Some ropes are very frictive and some are very compressible.
One or the other of these qualities can make or break salvaging the media.
As in your tree pulling thread, the more force you can keep from the nub of the knot, the easier it will be to untie.
Different knots for different tasks or ropes.
Some ropes are so slippery you'd almost want them to jam!

SS

preventec47

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Re: Categorizing and Organizing Knots for Reference
« Reply #12 on: March 20, 2015, 11:57:20 PM »
Hi preventec47.

I definitely don't agree with you concerning the statement that different types of cord/rope don't influence the jamming or untie-ability. Some ropes are very frictive and some are very compressible.
SS

I didnt say that.  I mentioned that regardless of the rope material
that the "relative"(compared to other knots)  untie-ability remains the same.  You could
still take a rated  "easy to untie" knot and tie it in frictive material
and it would jam.  Two aspects here and are different.  The knot
characteristics and the rope characteristics.  I am trying to remove
the rope characteristics from the knot rating chart.

Dan_Lehman

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Re: Categorizing and Organizing Knots for Reference
« Reply #13 on: March 21, 2015, 12:04:45 AM »
It seems to me that the "relative" anti-jamability in comparison
to all other knots would remain the same regardless of the
type of cord or rope used and ...
And yet somehow you managed to get a water bowline
jammed !?  We'd luv to see a photo of that, to better
understand; for the added turn in this knot ought to help
keep the return leg of the eye from getting pulled
through it and the basic turn, to tighten so much
around the S.Part !?  (I've seen bowlines where the
"collar" is pretty tight around the S.Part, and infer that
on heavy loading the material diameter diminished and
the collar was or got pretty tight around the S.Part
and on relaxation of force, the *swelling* of the rope
back towards normal, thicker diameter made this
collar-around-S.Part connection tight.  (I've also found
jammed sheet bends.)

So, not only the nature of the material, and the loading
--you elsewhere tell of quite dynamic, "shock" loading--,
but also how the knot is actually tied, figure in effect.
(Long ago we had some debate here about Ashley's bend
#1452
jamming, and eventually we learned that it was
not dressed in an orientation to prevent this --Ashley himself
doesn't address the variety of orientations & their effects.)

Quote
that the "relative"(compared to other knots)  untie-ability remains the same.  You could
still take a rated  "easy to untie" knot and tie it in frictive material
and it would jam.

But it's not so simple as this : e.g., in super-slippery HMPE
rope, movement occurs within a knot well past where it
would do so in frictive material, and that can defeat the
structural elements that had rendered the knot easily untied!
(It's not clear to me how much surface condition matters:
on the one hand, the friction impedes movement for the
loosening, but it might have also limited the delivered tension
into the knot, which helps!?)


--dl*
====

preventec47

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Re: Categorizing and Organizing Knots for Reference
« Reply #14 on: March 21, 2015, 12:58:06 AM »
Please forgive the laymen observations but to me it seems the
actual untieability in a knot is a function of a constant created by
the geometry of the knot multiplied by another constant defined
by the frictive compressiveness of the rope. ( terms/concepts I
just learned ).  So that  on a scale of 1 to 10 with 10 being the
easiest geometry to untie and the frictive compressiveness of
the rope being 100 to 1000.   This could illustrate that regardless
of the geometry, knots tied in some materials could never be untied yet the particular knot geometry could still carry a hi untie-ability constant.    It seems we kind of know this as it is common
sense that we have to both select the proper knot AND the proper
rope material.