What is Semantic searching or getting results from the web which uses semantics

Hi to all reading,

I hear about the semantic web, semantics and all this kind of stuff.  What is it?  Could you explain it to me.

For example if I put it into a practical example - If I search in Google / Yahoo / Bing - with certain words - are only these words searched for or are "other words" based on semantics also added to my search.  Or is the other way around and the webpage has to have the semantics built into it.

My interests are doing or understanding or making better searches and what tools are available for this.

I am sure I have not asked this right so feel free to ask me questions on what I really want to know.
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itsanxConnect With a Mentor Commented:
Thankyou. Feel free to ask if you have more questions. Information seeking research is a complex field because you are typically discussing issues one abstraction level above an unspecified information need. A user needs information about something and you need to find out how the user intends to retrieve it.

Try reading "3.2 Ellis’ Model of Information Seeking Behaviors" and specifically checking out figure 2 and 3 in the following article (it's old but still relevant):

To get a deeper understanding of information structures on the web, I highly recommend reading "Information Architecture for the World Wide Web" by Rosenfeld & Morville. The most recent edition is from 2006, but with the focus being on information theory rather than technical solutions, this should not be an issue.

You may also like to read "Kuhlthau's Model of the Stages of the Information Process" for a general overview of information seeking - it also contains several strategies:
cataleptic_stateConnect With a Mentor Commented:
itsanxConnect With a Mentor Commented:
I'll restrict my answer to a conceptual description.

Semantic searching is built around systems of organized knowledge. All terms in such a system have
some kind of logical relationship to each other.

A basic example could be:

1.) All elephants are mammals.
2.) All mammals are animals.

From these statements, you can infer that:

3.) All elephants are animals.

This is called syllogistic reasoning. It is a basic form of logic evaluation based on known definitions. If you build a database according to similar principles, it will allow a search engine to reason about and draw conclusions from the contents in the database. This type of knowledge encoding makes it possible to search for "four-legged gray animals" and receive a list of (among others) elephants, donkeys and wolves.
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darbid73Author Commented:
Thank you itsanx I was looking for someone own words and not just a link.  

So given your example - if I search right now for "four-legged gray animals"

1. does for example google exapnd the search to mamals, animals etc
2.  the webpages have this knowledge embedded in it.


do I need to type all the words myself - ie do I need to think semantically when doing the search.

itsanxConnect With a Mentor Commented:
Many semantic search engines are built around an OWL (Web Ontology Language) dataset and a logical reasoner. The reasoner outputs its conclusions to an interface, for example a webpage.

The application of such a search engine is often limited to a topic-specific dataset maintained by professionals in the field. However, some experimental projects are trying to establish semantic facts by having an AI freely crawling the web. This is not trivial due to the ambiguous characteristics of natural language and the common presence of contradictory facts. Not only does it require artificial logical reasoning, but also artificial source evaluation.

In an optimal case, the user can input their question in natural language without considering potential term frequencies or term ordering. The search engine will then analyze the subjects and apply the correct filtering rules.

To answer your questions:

1.) I do not know about google specifics but I am convinced that in most cases, some term expansion is occurring. It is probably based on term frequency statistics rather than semantic relationships. A common means of structuring search terms is a thesaurus containing loose semantic relationships (e.g. synonyms and antonyms).

2.) Yes. An "optimal" semantic search engine would have inferred its knowledge from the source webpages. It would then be able to summarize the information according to your preferences before you even visit the source web pages. Automatic knowledge gathering, if you like.

darbid73Author Commented:
Thank you again itsanx,

Your responses result in many searches to find out more information.  I now have a few semantic related words I can use.

I see 2 things here "Semantic Web" and "Semantic Search".  Neither seem to be matured yet but it is certainly a big topic.

Lets assume that I want to use an existing search engine to do "Research Searching " -
In Research Search, the user provides the search engine with a phrase which is intended to denote an object about which the user is trying to gather/research information. There is no particular document which the user knows about that s/he is trying to get to. Rather, the user is trying to locate a number of documents which together will give him/her the information s/he is trying to find.

One of the main hurdles is "Disambiguation"
In order to understand what a user is searching for, word sense disambiguation must occur. When a term is ambiguous, meaning it can have several meanings (for example, if one considers the lemma "bark", which can be understood as "the sound of a dog," "the skin of a tree," or "a three-masted sailing ship"), the disambiguation process is started, thanks to which the most probable meaning is chosen from all those possible.

How does this sound for what I want to do.

1. Take my text, or questions and use a tool or tools to get a. semantic expansion b. synonym / antonym expansion c. keywords
2. Maybe cut these results down a little to a manageable number.
3. Use existing search engines which may or may not have term expansion or term ordering.
Trying several methods for searching will almost always render higher precision results. Often, the difficult part of finding information is overcoming the ASK - Anomalous State of Knowledge (as introduced by Nicholas J. Belkin); you are aware that you need information, but you miss the information to describe it. Finding the right keywords through the use of expansion algorithms may be a part of the solution. For my own research, I have found chaining to be the most fruitful strategy. In chaining, the information seeker finds their sources among the source references of articles or books. More often than not, additional keywords are found during the process.
darbid73Author Commented:
Ok.  I think I have milked this question enough.  We could chat forever I imagine.

Thanks for the TIP about ASK and chaining I will look into that.  Do you have any reading on this "Chaining" as it is a common word.

I agree with you and will conclude that the key to searching here is:

Try to incorporate several word expansion methods into the search engines that currently exist like Google.
darbid73Author Commented:
The first response was a valid document, so I have given it points too.
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