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Overs Index

Page history last edited by PBworks 14 years, 11 months ago

Question - "What is the Overs Index (OI)"


Answer - The Overs Index is a simple means of classifying a knot in order to start the identification process or as a means of differentiating between very similar knots.


The Overs Index - The OI - has two parts X and Y and is written OI-X:Y


The X part is the Crossing Point value for the knot and the Y part is the Saturation Index of the knot.


The concept of counting Crossing Points was first utilised by Geoffrey Budworth to assist forensic analysts to identify knots. The method was introduced in Knots & Crime, published by the Police Review Publishing Company in 1985.


In order to calculate the OI of a knot, simply count up the total number of times threads cross over other threads. Then to identify the knot, go to the OI page corresponding to that number of crossings and compare your unknown knot with other knots known to have that same number of crossings.


To see a few examples of how it's done take a look at these Counting Examples. Sometimes counting the Crossing points is enough to give a unique identification to a knot, but sometimes a particular OI group might have a number of knots sharing the same X value.. When this happens, the Saturation Index, the Y component should be calculated in order to refine your search. Go to these pages to learn how to calculate the Saturation of any particular knot.



Then select the Overs Index page from the table below, corresponding to the knot you are trying to identify.



OI-1 OI-2 OI-3 OI-4 OI-5
OI-6 OI-7 OI-8 OI-9 OI-10
OI-11 OI-12 OI-13 OI-14 OI-115
OI-16 OI-17 OI-18 OI-19 OI-20
OI-21 OI-22 OI-23 OI-24 OI-25
OI-26 OI-27 OI-28 OI-29 OI-30






The Overs Index is intended to allow you to reduce your knot identification problem by dividing knots up into small groups with the same OI. If you fail to find a match to the knot you are trying to identify, then please publish its details on the IGKT Forum at http://www.igkt.net/cgi-bin/yabb/YaBB.cgi?board=news

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