Chapter 1 Introduction

Examples Many election year polls s/general_election_romney_vs_obama-1171.html

Examples  Surveys about the US:  American Community Survey  Consumer Price Index  Unemployment Rate (political hot potato!)  Billion Prices Project MIT (sampling?)  Nielsen TV Ratings 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.ABC 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.”Charles Kennedy

Top shows of a recent season 1.Sunday Night Football NBC American Idol (Wed.) Fox NCIS CBS American Idol (Thu.)Fox Dancing With the Stars ABC NCIS: Los Angeles CBS Dancing With the Stars Results ABC The Big Bang Theory CBS 15.9 * The Voice NBC The Mentalist CBS 14.8 Nielsen Ratings (name, network, avg. weekly viewers) Top shows of a recent season (18-49) 1.Sunday Night Football NBC American Idol (Wed.) Fox 8 3. The Voice NBC Modern Family ABC The Big Bang Theory CBS 7.1 * American Idol (Thu.)Fox Two and a Half Men CBS Broke Girls CBS 5.6 * The X Factor (Wed.) Fox Grey’s Anatomy ABC 5.5 Statistics and data determine which shows survive and which are canceled

Data Determines Ratings. Ratings Are IMPORTANT! million-on-cbs

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.

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 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 n The high cost of obtaining data has driven survey firms to the internet. n 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 n YouGov – what the world thinks panel/

Non-Probability Sampling: Many Online Data-Gathering Services (Free, Pay) n Google Consumer Surveys Google Consumer Surveys n Google Trends Google Trends n Google Analytics Google Analytics n Twitter Analytics Twitter Analytics n Facebook Analytics Facebook Analytics n Microsoft Microsoft n Yahoo Yahoo n Amazon Amazon

Example: ViralHeat (fee-based)

The Billion Prices MIT n 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