on grade posting time-frame..

Folks:

 Sorry I had to leave in the middle of the exam; hope you survived the rest without much pain.

 I am going to be out of town starting tomorrow and until 18th. I will try to post your grades as soon as I can, but did take permission for late
posting just in case.

regards
rao

Cheat sheet e: Question regarding the scope of the final exam

Yes. One sheet 8.5x11 both sides

On Saturday, May 8, 2010, asael sorensen <Asael.Sorensen@asu.edu> wrote:
> Did you decide on whether we can use a cheat sheet or not?
> Ace Sorensen
> 602.633.5477
> acylt.com
>
>
> On Sat, May 8, 2010 at 12:57 PM, Subbarao Kambhampati <rao@asu.edu> wrote:
>
> Comprehensive with bias towards post-midterm topics
>
> rao
>
>
> On Sat, May 8, 2010 at 12:14 PM, Jeff Zhang <xiaolong.zhang.1@asu.edu> wrote:
> Hi Dr. Rao:
>
> Someone asked this question in class once, but I forgot how you answered it. So I'm wondering if the final exam will be scoped towards contents after the mid-term or would it be comprehensive?
>
> Thanks,=============================
> Jeff Zhang
> Department of Computer Science Engineering
> Arizona State University
> 699 S. Mill Ave Suite 371
> Tempe, Arizona
> Voice: (480)-208-5675
>
>
>

Re: Question regarding the scope of the final exam

Comprehensive with bias towards post-midterm topics

rao

On Sat, May 8, 2010 at 12:14 PM, Jeff Zhang <xiaolong.zhang.1@asu.edu> wrote:

Hi Dr. Rao:

Someone asked this question in class once, but I forgot how you answered it. So I'm wondering if the final exam will be scoped towards contents after the mid-term or would it be comprehensive?

Thanks,
=============================
Jeff Zhang
Department of Computer Science Engineering
Arizona State University
699 S. Mill Ave Suite 371
Tempe, Arizona
Voice: (480)-208-5675

homework 4 solutions posted; acquired wisdom link posted

Folks:

 The solutions for homework 4 are online.

 I also put a link to the blog review of the course content (as posted by you) from the lecture notes section. I have read each one of them, and I would encourage you to do so yourself so you can get an idea of what you may have missed that others seem to have caught (or vice versa)

Rao


ps: Here is an interesting mini-project idea involving collaborative filtering to suggest ideas from course to students
          1. Extract structured record from the postings
          2. make an studen-topic matrix
          3. Use collbaborative filtering to recommend, for each student, one or two topics that they might like because students
               just like them seem to like those topics..


          

internship in IR and data mining with a startup company

Prof. Hasan davulcu (HasanDavulcu@asu.edu) asked me to announce to the class that he has several internships in IR with a startup company that he believes the students of this class might be eligible for, and would be interested in.

If you are interested in finding out more, please send a note to him directly (mail address above)

regards
rao

Participation evaluation sheet

folks:

 Please note that you will need to fill-up and turn-in a hard copy of the enclosed participation evaluation sheet in tomorrow's class (I will bring a few blanks
just in case; but you might be better off filling it at home so you have all the correct stats).

regards
Rao

Re: Question about keyword search on RDF data

I think there are two parts to your question. One is what does it mean to do keyword search on structured data such as RDF. The second is whether keyword queries have to converted into some form of structured queries just to run on RDF (or RDBMS).

This issue has received significant attention in the DB community (recall that RDF can be seen as just a format for Relational data), so let us start there.

Suppose I have a database, and a user gives a keyword query, what tuples in the database should be given as answers to this query? 

The answer is simple if the database has a single table--you just select all the rows that have the keywords in them (modulo some tf/idf extension)

However, most databases are "normalized"--that is, they split a wide "universal tuple" into many small tables. This means that you can have a situation where the keywords are spread over different rows in different tables. [Suppose we have two table [sid, name] and [sid, hobby] (where sid is student-id) A keyword query "rao tennis" will now have to be answered by seeing if there is a join between these two tables over sid that gives a row which has both rao and tennis in it. [The issues remain same whether the database is in RDF format or normal RDBMS one]

So, answering keyword queries will require you to either do arbitrary joins during the query processing stage, or *de-normalize* the database up-front so that you have the full universal relation in front of you (and so can do simple row selection). The former would require more work during query time (in as much as it will force you to rewrite the keyword query into a set of join queries), while the latter kills the structure to support keyword queries. 

The latter approach, as counter-intuitive as it might look for a database person--is actually the one that is used by most search engines that allow keyword access to large-scale databases (in fact, they write each individual universal tuple out as an html file. This process is given a fancy name--"Surfacing of the deep web"). 

The former approach--involving query-time joins to reconstruct universal tuples--started with a system called "BANKS". The problem becomes harder when the primary-key/foreign key joins between the various tables are lost, as might be the case for web databases. See http://rakaposhi.eas.asu.edu/smartint-icde10.pdf

=======

As for the answer to the second question--whether keyword queries get converted to SQL-style queries, "yes" if you use Banks-style approach and "no" if you do surfacing. 

Hope this answers your question.

Rao

On Thu, Apr 29, 2010 at 1:27 PM, Siva N <snatara5@asu.edu> wrote:

Professor,

I was having some questions about supporting search on RDF data..

I understand that RDF/RDFS data defines ontology and more semantics to the data and is much closer to structured data such as in relational DB. So does that mean that all queries to RDF data must be of SQL style queries and IR style keyword search may not be applicable ???

So if we were to try developing a keyword search engine on RDF data, does that have to be something like providing keyword search interface and then internally converting the keywords into SQL style queries and retrieve results from RDF data ??

Is doing plain IR-style keyword search on RDF data does not fully utilizes the structured nature of the data and does ontology based search engines are always best suited for RDF data ??

Thanks,
Siva
--
Graduate Student, MS Computer Science
School of Computing and Informatics
Mobile : 520 582 4479