This is a part of the Introduction to Wubi Input Method series. Previous chapter was about secondary shapes and shortcuts.

In this chapter we will make sense of the most tricky part of Wubi, the isolation rules.

Basic idea of Wubi, inputting shapes in the order in which they are written, is both simple and powerful. But the amount of shapes assigned to each key presents ambiguity problem. This gets especially serious with relatively simple characters that consist of two or three shapes. Sometimes the characters have exactly the same shapes and writing order like and , and somethimes different shapes correspond to the same key like and .

Therefore, we have to come up with a clever solution to isolate characters with same shape keys, that is, a solution that would give us different codes, for example we can add a different letter to the code. It is reasonable to use the differences in the characters for that, of which we have 1) different configuration of the characters and 2) different shapes.

This is exactly what the Wubi author was thinking, so he classified possible character configurations into three groups: left to right, top to bottom, and other.

left to right ⿰⿲
top to bottom ⿱⿳
other ⿴⿵⿶⿷⿸⿹⿺⿻

As for the shapes, the easiest way to classify them is by strokes, so they are divided into five groups according to the last stroke of the character.

Now we combine this into a five by three matrix, and that is where we use the stroke keys we have studied earlier. So, if you want to find an isolation key to add to the code, you observe the last stroke of the character, and then if it has vertical (mostly left to write) configuration, you use the corresponding stroke key, if it has horisontal (mostly top to bottom) configuration, you use the ‘double’ stroke key, and for other characters you use the ‘triple’ stroke key.

  left to right top to bottom other
g f d
h k l
丿 t r e
y u i
n b m

This part of Wubi requires most perseverance and the amount of thinking that you have to do will seem detrimental to your typing skill at first, but believe me, it can be trained up to half-consious level just as any other skill.

Let me give you some examples of how to use the isolation rules.

Suppose, you want , so you identify the shapes and go for us. However, instead you see only . First you notice that the last stroke of is a leftward stroke, so you go to the region, and you also can see that the configuration is ⿸, neither left to right, nor top to bottom, so you will require the triple key, and when you add it, you get ysi.

Or, of you want , the code starts with cf, and you notice that the last stroke is horisontal , and the configuration is top to bottom, so you in fact need double horisontal stroke key, and the code is cff.

And the last example with three shape character, . If you input stf, you get . So, you notice that the last stroke of is vertical, and the configuration is left to right, so you need a single vertical stroke key, making the code stfh.

It will probably take some time to ponder it over, so I am leaving you to your practice. In the next chapter we will go beyond typing single characters to unleash the full power of Wubi.