Saturday, November 10, 2007

Context and Situation - are they synonyms?

I have spent the last couple of days in Eilat a resort town near the Red Sea, the Las Vegas of Israel, if one counts hotels, and an interesting combination of dessert and beaches in a small proximity, in the picture you can see the hotel in which we stayed. Anyway - back to context. A comment that received to the previous posting made me realize that there is a need to explain what is the difference between - "context" and "situation", both of them are semantic terms. In a way - it is similar (but not identical) to the difference between "state" and "transition". "situation" is something that happens, and that has some meaning in the consumer's terms, and it is the event consumed by the consumer(and as a result may trigger an action), in syntactic terms, situation is an event, and may be either raw or derived event (I'll not get into complex / composite events - it is sufficient to say it can be any kind of event). Context is a state -- a context can be created by the occurrence of event and destroyed by the occurrence of another event. Let's take a simple context: "during red alert". There is an event that declares the "red alert" state, and then there is an event that declares any other color, and it is considered to be "converse event" to the starting event, thus, it end the context. While the declaration of "red alert" is an event and can also be a situation, the fact that another event happened "during red alert" is not an event (semantically). Context may also be spatial - for fleet management application - a context may be a geographical area - and the events are that a vehicle enters and exits a context, but the fact that a "vehicle is within the area" is not an event.
Thus "context" has a distinct semantic existence. As far as implementation goes - there are various relations between events and contexts. After writing my first blog about context - somebody attracted my attentions that analysts have been recently talking about "context-aware delivery architecture" - I'll refer to this four letter acronym (are we out of all combinations of three letter acronyms?) in one of my next blog.


Tim Bass said...

Hi Opher!

Nice blogging! Keep up the great work!

To elaborate, context can be used to define and detect situations.

Situations are often defined as, "the condition" or "the current state of affairs".

Therefore, the term "situation" is more knowledge and information rich than "context".

Context is commonly defined as "the set of circumstances or facts that surround a particular event, situation, etc."

Therefore, "context" is used to describe, define and detect "situations" and generally speaking, the more context you have, the better a situation can be "perceived."

We could go into cognitive theory, perception, knowledge management and sensor fusion basics to further elaborate and refine the concepts.

Yours faithfully, Tim

Tim Bass said...

Hi Opher,

OBTW, I responded to this topic in this post:

Yours sincerely, Tim