The Last Blog!

It is an amazing and indeed a fortunate opportunity to be among the first few students of the Institute and your advisor. Why? Because being the first few puts you in the experimental zone, especially for the advisor; this allows all parties (institute, advisor and oneself) to explore the best way growing together. Institute was new and flexible, rules were still to be imposed, Prof. Jalote and other professors would interact on a daily basis and it was a flat open culture. I believe and in my experience, those were the most productive and professionally healthy years, but the organisation and structure followed and a little of the culture got lost.

This blog is not about cribbing; It is about learning, appreciation and growing up. I am writing of my nostalgic 6 years at Precog and IIIT-Delhi. I am writing of the time, that had constantly pushed me out of my comfort zone. I am writing of the time when I grew to maturity. My advisor, and Institute were excited to have first of their PhD students. But, allow me to focus on PK’s excitement over the years and the learning I had from him.

Lead: People say that I have a part of PK’s personality in me now. PK has a wonderful charisma and ability to lead. He started Precog, founded CERC, first in the Institute to help establish the brand, organised SPSymposium, collaborate, and network. He actually has a ‘following’ of every genre of professional career and that shows the impact of his leadership. I tried to learn a bit of it on a small scale. Learn to drive and push group sessions (Brainstorm paper reading), lead a small group to competitions, motivate fellow PhDs and help them, and most importantly lead myself! Long way to do things at the scale PK does.

Generous: I have always been a generous person, not in money but in time. PK has been a generous person both in money and in time (to me, because we had little distractions in initial years of my PhD and this is the advantage of being the first few). I have heard from many that their advisors pay a little heed on what you are doing, most forget the problem their PhD students are working. PK fluctuates in this behaviour. He micromanages at some times, else leave to let us swim on our own. He generously gives away his travel, invitations, talks, etc., when any of us starts complaining of his time. Well, I believe it needs courage to prioritise students over oneself. He made sure that he was there to help fulfil our dreams, he certainly did mine. Working with such an advisor made me realise the organisation of priorities. I try to work with fellow PhDs as much as I can to offer time, review cycles and help. I have now become generous in money too, btw!

It’s okay to fail: I really wish to talk about the group dynamics and behaviour here. I just love and appreciate Precog’s true culture of helping and criticising, sharing and fighting, growing together and selfishless attitude. Niharika, Srishti, Prateek, Anupama, Aditi, are the few fortunate ones to have worked with me! (:P) The group made sure that everyone is doing fine, technical errors were thrashed (not humiliated). We still complement each other and I believe that is the power of Precog. It is important to have calm, confused, impatient, strong, hyperactive, and mature people, all seated in the same room together. They constitute a part of my support structure and they were there when I ‘Failed’! So, whenever the group has a rejection, we celebrate! Funny! I distributed chocolates when I got my rejections. The group teaches you the power of collaboration, company and failure. I really missed all of you at the convocation!

My fellow future PhD graduates, I really wish that you make the best of the opportunity (or create a few for you / others). In industry, I see the importance of independence, the attitude of running with one’s problem and most importantly, fall in love with your work each day.

Good luck Precog and to IIIT-Delhi PhD students. Strive, Fight, Connect, Learn from Other’s Failures, Talk, Present, Do the Quality Work, No Shortcuts, Trust your advisor, Trust yourself, Believe and Fight Back!

“It’s not how hard you hit. It’s how hard you get hit…and keep moving forward.” Randy Pausch, The Last Lecture

To maturity, to success!


            Dr. PK with Dr. PJ on our graduation day!

Know your caller – The SocialCaller App!

Getting a spam call in the middle of the day is not a new problem most of us face in our day-to-day life. One often wonders on the name of the caller and to why that person is calling you. Further, getting to know “who” is calling you is good (Truecaller), but the important question still remains. “Why” the other person is calling? Might be, getting to know the name of the caller is insufficient to allow the receiver of the call to make the decision whether to attend to the call or not.

Now, how do we know why the other person is calling? Well, one good medium to answer the question is – Online social networks [1]. During our research, we observed that many Indian users post their mobile numbers on popular online social networks as Twitter and Facebook to either promote the number in context of business or to stay connected with the friends.  Therefore, a tweet / bio on Twitter or a status update on Facebook exposes the real motive of sharing the mobile number.

Further, users make the posts public (posts with their phone number), thereby making the post accessible to anyone on the Internet. We deployed a mechanism to collect all such publicly shared mobile numbers in public posts, bio, or status updates. Currently our database has around 75,000 mobile numbers collected from Twitter and Facebook.

With this big and continuously growing database, we developed SocialCaller, an Android app (v2.3+), which provides the following two functionalities. The app is available freely at Google Play store.

  • · An online app – When a call comes, the app will show the number, the Tweet, Bio or status update associated with the number, the location of the user who posted that number and the social network where it was published. This service needs Internet connectivity at the time of call. We also store how many times a number has called up other users, and therefore how many times the number was queried in the database.
  • An offline app – This service is supported even when there are no calls. In case someone gets a missed call, or need to know more about a number, he / she can use this service to query the number and the corresponding details will be presented. This service needs Internet connectivity as well.

Please feel free to download this app from the Google Play Store. In case of any suggestions or feedback, please write to

Keep Calling!

[1]: Jain, P., Jain P., and Kumaraguru, P. “Call me maybe: understanding nature and risks of sharing mobile numbers on online social networks.” Proceedings of the first ACM conference on Online social networks. ACM, 2013.

Obrigado Rio @ WWW 2013

At IGI Airport, in a flight at 4:15pm, talked to all my family, friends, colleagues, and told them that `THE TRIP’ was finally taking place. Scared, excited, ready to learn and explore, I knew the trip bagged many things for me. I was flying to RIO DE JANERIO, BRAZIL (The Trip), to attend WWW conference to present joint our work with Prof. Joshi on “Identity Resolution” at WoLE. This was my second WWW, after 2011.  Thrilled, I kept on polishing and practicing my presentation in the flight, people thought I was weird because I was talking too much IDENTITY (u see).

Reached Rio, settled down, roamed around a bit and then started the academic excitement. First day, first workshop, first presentation (May 13th, WoLE, 2pm), sitting with PK in the same room, my first International presentation made me all shiver on the stage. Though conference people had very nice infrastructure that presenter could see slides on a screen placed at the right eye angle and that comforted me. On the successful completion of the presentation, multiple researchers approached to discuss ideas and to know more about the work.  To my surprise, the paper bagged “Honorable mention for the best paper award” [1].

Rest of the WWW days kept us (PK and me) on toes, with paper presentations in 24 rooms, spreaded out across 5 floors, 125 research papers + workshop + demos + posters. WWW had 22 social network papers, out of 148 papers submitted, 15 security papers out of 82 submitted and 11 user interface papers, out of 55 submitted.

After attending an amazing keynote by Luis Von Ahn on Captcha and Duolingo, we rushed to attend our marked sessions in the conference booklet. Some very interesting sessions on how to smartly pick mechanical turk users, to give them something they like to annotate [2], how to remove near-duplicate tweets from Twitter and why do it? [3], how timestamps and content created by users can be used to correlate their accounts on multiple social networks [4], how shortened URLs clickthrough behavior can help building the user profile and disclose her identity [5], characteristics of Q-A forums as Quora [6], prediction of evolution of user activity graphs for an social media app [7], why and how criminals hold on valid domains for profit (cybersquatting and typo squatting) [8], etc. One interesting paper on predicting a group stability on an online social networks, said that radioactive decay was observed while detecting user engagement in game / site / application, however they claimed different observations for DBLP network [9].

Apart from technical learning and experience, we got to meet smart people around during poster sessions, research tracks and coffee breaks. Few kind professors and senior PhD students also responded with meeting slots when I requested them. And few good professors invited to roam around the city and experience Rio specialties.

We returned with one best paper award (Aditi’s work on credibility [10]), one honorable mention award, a problem for next WWW, loads of memories and sad faces.

Brazil was an amazing fun loving relaxing city. I got to see beaches, which I had been thinking of, since my first year in PhD. I got to meet my old friends in Rio, and made new friends as well, tried new cuisines, food, places, art, history, and above all, the Christ. Ahh, the feeling of ticking off another wonder from your list, was just amazing.

Thanks to all Precog members, and special thanks to PK for supporting me in all ways (kind to give away his travel grant to add to my travel grant to cover the trip expenses).

Attached is the moment, to say it all in one go:

[1]: Paridhi Jain, Ponnurangam Kumaraguru, and Anupam Joshi. 2013. @i seek ‘’: identifying users across multiple online social networks. WWW ’13 Companion.

[2]: Djellel Eddine Difallah, Gianluca Demartini, and Philippe Cudré-Mauroux. Pick-a-crowd: tell me what you like, and i’ll tell you what to do. WWW ’13

[3]: Ke TaoFabian AbelClaudia Hauff, Geert-Jan Houben, Ujwal GadirajuGroundhog day: near-duplicate detection on Twitter. WWW ‘13

[4]: Oana Goga, Howard Lei, Sree Hari Krishnan Parthasarathi, Gerald Friedland, Robin Sommer, and Renata Teixeira. Exploiting innocuous activity for correlating users across sites. WWW ’13

[5]: Jonghyuk Song, Sangho Lee, and Jong Kim. I know the shortened URLs you clicked on Twitter: Inference attack using public click analytics and Twitter metadata. WWW ’13

[6]: Gang Wang, Konark Gill, Manish Mohanlal, Haitao Zheng, and Ben Y. Zhao. Wisdom in the social crowd: an analysis of quora. WWW ’13

[7]: Han Liu, Atif Nazir, Jinoo Joung, and Chen-Nee Chuah. Modeling/predicting the evolution trend of osn-based applications. WWW ’13

[8]:  Nick Nikiforakis, Steven Van Acker, Wannes Meert, Lieven Desmet, Frank Piessens, and Wouter Joose. Bitsquatting: exploiting bit-flips for fun, or profit? WWW ’13

[9]: Akshay Patil, Juan Liu, and Jie Gao. Predicting group stability in online social networks. WWW ’13

[10]: Aditi Gupta, Hemank Lamba, Ponnurangam Kumaraguru, and Anupam Joshi. Faking Sandy: characterizing and identifying fake images on Twitter during Hurricane Sandy. WWW ’13 Companion.