Chapter 1 Introduction
Examples
Many election year polls
http://www.realclearpolitics.com/epolls/2012/president/u
s/general_election_romney_vs_obama-1171.html
Examples

Surveys about the US:
 American Community Survey
http://www.census.gov/acs/www/
 Consumer Price Index
http://www.bls.gov/cpi/home.htm
 Unemployment Rate (political hot potato!)
http://www.bls.gov/cps/

Billion Prices Project MIT (sampling?)
http://bpp.mit.edu/usa/
Nielsen TV Ratings
http://www.nielsen.com/us/en/top10s.html

How does Nielsen work?
DVRs Shift Viewing Habits, and Ratings
by Gary Levin, USA TODAY
June 11, 2014
The increasing usage of digital video recorders, which easily allow viewers to
postpone watching their favorite shows, has vastly complicated the math of
TV ratings, new Nielsen data show.
And it explains how ABC's Modern Family ultimately eclipsed Fox's
American Idol among key young-adult audiences.
Among viewers ages 18 to 49, the comedy jumped 48% when factoring in
delayed viewing, while Idol's performance show gained just 17%.
But viewers rarely delay reality shows, news, awards telecasts and sports
programming by more than a day. Sitcoms and dramas are most prone to
procrastination, accounting for 29 of the top 30 gainers.
"DVRs continue to play a more important role" in overall viewing, says ABC
research chief Charles Kennedy … “What's suffering at the hands of the
DVR is old-fashioned channel surfing.”
Statistics and data determine which shows survive
and which are canceled
Nielsen Ratings
(name, network, avg.
weekly viewers)
Top shows of a recent
season
1.Sunday Night Football NBC 20.7
2. American Idol (Wed.) Fox 20.1
3. NCIS CBS 19.7
4. American Idol (Thu.)Fox 18.5
5. Dancing With the Stars ABC 18.3
6. NCIS: Los Angeles CBS 16.3
7. Dancing With the
Stars Results ABC 16.2
8. The Big Bang Theory CBS 15.9
* The Voice NBC 15.9
10. The Mentalist CBS 14.8
Top shows of a recent
season (18-49)
1.Sunday Night Football NBC 10.2
2. American Idol (Wed.) Fox 8
3. The Voice NBC 7.9
4. Modern Family ABC 7.4
5. The Big Bang Theory CBS 7.1
* American Idol (Thu.)Fox 7.1
7. Two and a Half Men CBS 6.6
8. 2 Broke Girls CBS 5.6
* The X Factor (Wed.) Fox 5.6
10. Grey’s Anatomy ABC 5.5
Data Determines Ratings.
Ratings Are IMPORTANT!
http://www.businessinsider.com/super-bowl-50-ad-rates-reach-a-record-5million-on-cbs-2015-8
How do we obtain data
for surveys such as
those above?
Would you fill out a survey that …
Would take 2 hours of your time?
 has 30 essay questions?
 asked about your favorite yogurt?
 asked if the college football playoff
should be expanded to 8 teams?

Would you be comfortable telling
a researcher about …
your finances?
 your participation in illegal
activities?
 personal medical information?
 whether you have cheated on
an exam during the current
academic year?

To be useful, a sample should be
representative, meaning that
characteristics of interest in the population
can be estimated from the sample with a
known degree of accuracy.
http://abcnews.go.com/blogs/politics/polls/
Opinion Polling: What’s Wrong Lately?
Prediction slippage:
 2012 US presidential election (correct
winner but not very accurate)
Recent inaccurate predictions:
 2014 US midterms
 2014 Scottish independence referendum
 2015 UK election
 2015 Israeli general election
 2015 Greek bailout vote
Response Rates Declining
Contacting People-Extremely
Difficult
Contacting People-Extremely
Difficult - 2
1. Robo-calls (auto-dialed)
calls to cellphones NOT
ALLOWED
2. To obtain between 700 and
1,000 cellphone interviews
when response rate is 8%,
approx. 10,000 cellphone
numbers must be manually
dialed – budget buster!
Non-Probability Sampling
 The
high cost of obtaining data has
driven survey firms to the internet.
 Non-probability sampling:
participants are chosen or choose
themselves so that the chance of being
selected is not known.
– Major problems with internet polls
– No one has figured out how to select a
representative sample of internet users
85% of US Adults Use the Internet
*Blogs (e.g. Blogger, Wordpress), Microblogs
(e.g. Twitter), Social networking (e.g. Facebook),
Content sharing/discussion (YouTube, Reddit)
Non-Probability Sampling:
Opt-In Online Panels
– what the world thinks
https://today.yougov.com/about/about-the-yougovpanel/
 YouGov
Non-Probability Sampling:
Many Online Data-Gathering Services
(Free, Pay)
 Google
Consumer Surveys
 Google Trends
 Google Analytics
 Twitter Analytics
 Facebook Analytics
 Microsoft
 Yahoo
 Amazon
Example: ViralHeat (fee-based)
The Billion Prices Project @ MIT
 http://bpp.mit.edu/
Aggregates millions of daily e-commerce transactions into a
real-time price index for US, China, and ten other countries
In the next chapter we will
learn the basic terms and ideas
associated with sampling.
End of Chapter 1