2 Question 1 (2 points)
What is homophily? Why is this important in behavioral targeting that uses social information?
3 Question 2 (6 points)
Please answer the following questions based on the Liu and Tang paper  which was discussed in class. Each part carries 2 points.
1. The paper talks about a trade-off between an individual’s profile and social information
in behavioral targeting. Identify a case when using social information is likely to yield
poorer results. Explain why.
2. Identify a case when using social information is going to be very valuable. Explain
3. Refer to Figure 2 from the paper(while is also given in class slide 30). Lets look at the
ad clicks for the category Hispanic targeting in this figure. Explain why the likelihood
of clicking on a display ad is so high if at least one friend has clicked on an ad in this
category compared to the case when no friends have clicked on any ad.
4 Question 3 (2 points)
If you are an advertiser and you develop a behavioral profile for an user, should you focus
on their long term or short term interests? How will you make decisions on what you do?
Explain with reasons.
5 Question 4 – Advertising models (10 points)
This is a 3 part question. The questions are based on the discussions that was carried out
in-class about advertising model on 10/25 and 11/01. The first question carries 4 points,
while the others carry 3 points each.
1. This question is based on the advertising model of Stack Exchange. Their advertising
model is as follows—It has high bar for entry, you need to have at least 10000 USD
to spend. There are no auctions. The advertising is based on contract. There is no
real-time bidding. Discuss and identify two positive and two negative aspects of this
advertsing model compared to real time bidding.
2. The second question is based on the precise micro-targeting practices of consumers
that happens during behavioral targeting and computational advertising in general.
Advertisers micro-target consumers at fine grained level. However, should we consider
such micro-targeting as predatory or unfair for more vulnerable consumers like the
elderly or children? In other words, is micro-targeting in the context of vulnerable
population a positive or a negative development? Discuss.
3. Based on your discussion of micro-targeting scenario in the previous part, now consider
this case— the display of political ads in a platform like Facebook is based on microtargeting. Similar to Twitter, should Facebook ban all political ads on its platform?
 Kun Liu and Lei Tang. “Large-scale behavioral targeting with a social twist”. In: Proceedings of the 20th ACM international conference on Information and knowledge management. ACM. 2011, pp. 1815–1824.