The background to this post can be found in a very much earlier post, http://www.sqlnotes.net/drupal5/index.php?q=node/684&page=1 - [node:684,title="Is it a bird or is it a plane"]

All I am seeking to do is to classify items. This is not at all the same thing as categorisation – these days, more popularly known as tagging.

In some contexts, we organise items in accordance with a hierarchical classification scheme - a taxonomy. The classic example is a library, where a book can appear in one and only one place, indicated by its classification – for example, its Dewey Decimal classification.  

 

In other contexts, we want to be able to categorise or tag an item by multiple criteria, so that we can reach the item from a number of different routes. The difference between categorisation and classification is made by (Jacob, 2004) and further discussed by (Sinclair, 2008, 2007). They see categorisation as “the process of dividing the world into groups of entities whose members are in some way similar to each other”. Classification, by contrast, is the process of dividing a set of entities into mutually exclusive classes related according to formally defined rules. “A classification scheme is a set of mutually exclusive and non-overlapping classes arranged within a hierarchical structure and reflecting a predetermined ordering of reality.” (Jacob, 2004, p.254)

 

That is quite enough academic background. How can I classify things in InfoQube? It is easy to categorise them – for example, using wiki tags. After several years of trying, I have found no reliable way to classify things in InfoQube, even in a simple one level classification: example, vegetable or animal or mineral. To do what I really want to do, which is to classify things in accordance with a hierarchy – animal can be mammal or reptile or invertebrate, etc – I find it impossible to achieve.

When I say reliable: consider the following. I have defined the field classification as text. In the editor entry, I have specified:

select item as Classification from project order by left(item,100) asc

I have specified that "entry must be in list".

 

The idea of keeping permitted classifications in a grid based on the field project is that I can easily change the list of permitted classifications, without having to change the definition of a field.

If I create a grid based on classification, it appears to work and I have a drop-down menu from which I can select a value. However, I can also type any old rubbish into a new item, and despite the fact that "entry must be in list" is specified, the value is accepted.

If I add the field classification to an existing grid, and click on it, when I click on the down arrow in the hope of being able to select a classification, I receive the message:

Cannot show the list.
The query: select item as classification from project order by left (item, 100) asc
could not be executed.

When I acknowledge that message, InfoQube goes into a tight loop, consuming 25% of the processor power on my four processor system. The only thing I can do is to abort InfoQube and start over again.

Am I misunderstanding something here?

Is there any plan to make single level or multiple level classification a part of the end user interface of InfoQube?

 

WORKAROUND

 

The workaround that I have been using is to have a field defined as auto-list in the editor section of the properties. This works, but is subject to the limitation that there is no validation, so once again you can put any old rubbish into the field.

MOTIVATION (example)

I want to be able to classify a list of things to do. The reason I want classification and not categorisation is that I want to be able to be certain that I have gone exhaustively through every item in my list of things to do, classification by classification: dealing with all the animals, then all the vegetables, then all the minerals.