Re: [xdi] More example graph notation reflecting comments

[Markus Sabadello <markus.sabadello@xdi.org>]

I don't really have a very strong opinion, only a slight preference for leaving it how has been, except for removing the literal shape.

But these two variations look appealing to me as well, now that the characters have been removed.

A good argument for your first option would be that it would uphold the rule of

number of statements in the graph == number of arcs in the diagram == number of lines in the XDI DISPLAY format

A good argument for your second option would be that in contextual statements (e.g. =markus/()/<+email>), the () never shows up in the diagram.

So it may make sense that in literal statements, the second & also never shows up in the diagram.

Markus

On Wed, Sep 11, 2013 at 6:50 PM, Drummond Reed <drummond.reed@xdi.org> wrote:

Per the previous thread, I've created two more versions of a simple example graph reflecting Markus's and Joseph's suggestions.

The first one eliminates the multiplicity characters in the shapes. I must agree with Markus, this makes the graph look much simpler visually. OTOH, I disagree with Markus that it's not worth using different shapes for entity nodes and attribute nodes. Especially in this simplified form (without the multiplicity characters inside the shapes), I think it is very valuable to be able to see in a glance which nodes are entities and which are attributes and which are values.

The second example below is even simpler. It reflect Joseph's suggestion of removing the literal arcs and just putting the value (if there is one) next to the value node. I must admit, I really like this just because of how simple and intuitive it is. If a value node has a value, it is shown, otherwise no value is shown and it is undefined.

I appreciate Markus's point about showing the three kinds of arcs in the XDI graph model, because I do think this is a very important part of the model. However in terms of teaching the XDI graph model, it seems to make it much simpler if we leave out the detail of needing a literal arc and & predicate every time you have a value. Rather, my suggestion is that  we explain that once (and show it once) up front when we are introducing the notation, and then leave it out after that.