The broadcast ratings for Terminator: The Sarah Connor Chronicles is one of many factors a network may consider when deciding to renew a television show. Nielsen Ratings are audience measurement systems developed by Nielsen Media Research to determine the audience size and composition of television programming. Terminator aired on Monday nights during Season 1 and the first half of Season 2. After the winter break, FOX decided to continue with Season 2 and moved Terminator to Fridays nights to pair up with the debut of Dollhouse. Fans of both shows became concerned about this move, because it is known as the Friday night death slot — the timeslot shows are sent to die. The move to Fridays did result in lower ratings, though a slight upward trend appeared in the back 6 episodes.
There are three types of viewing Nielsen regularly measures and reports. Live viewing, live plus same day DVR viewing (these are the most commonly reported numbers) and live viewing plus seven days of DVR viewing.  The cut-off time for Live+SD (live plus same day viewing) is 3:00AM local time when meters transmit daily viewing to Nielsen for processing. Nielsen says Live+7 is "incremental viewing that takes place during the 7 days following a telecast."  
In addition to their traditional program ratings Nielsen now also offers commercial minute ratings which are an average rating for all national commercial minutes during a program. They offer this commercial rating for all ratings streams. Starting with the 2007-2008 season most ad buys are based on the commercial minute ratings from the live+three day DVR rating stream. This combination has become known as the C3 rating, short for commercial and three day.
For Terminator on Fridays, the ratings for DVR viewing has been significantly higher. According to James Hibberd of the Hollywood Reporter, the Live+7 data for the mid-season premiere episode gained a 36% increase.  However, Robert Seidman of TVbytheNumbers says, "percentage based increases are misleading because the shows with relatively few viewers overall, but still relatively good DVR viewing numbers show the highest percentage increases." 
Also, since advertising is bought and sold on C3 data (measurement of how many are watching the commercials), TVbytheNumbers says that, "So far as we can tell DVR viewing doesn’t meaningfully add to a networks ability to make money, and more people watching shows via DVR isn’t good news for the networks...most people using DVRs usually avoid commercials...the C3 data doesn't differ significantly from the live viewing, and that the relative performance of shows using the live plus same day DVR viewing is a good proxy for predicting success or failure." 
On February 17th, 2009 a blog post on the official FOX site told viewers how they can help boost attention and ratings. .
Some highlights include:
- DVR it and watch it again (and again) within THREE DAYS.
- Watch it again on FOX.com.
- Make Terminator #1 in the iTunes TV store as well as Amazon.com.
- Email friends, family, coworkers, reporters, bloggers, pets, etc and explain to them WHY this show matters to you.
Read the full list.
For Terminator: The Sarah Connor Chronicles to be renewed, the C3 data has to be good (determined by the network and advertisers). This means if you want this show to succeed, following the tips above like watching the show live or on your DVR within 3 days, will help the C3 ratings.
- View all charts by themselves on the charts subpage.
Season 1 vs. Season 2
The premiere episode had an exceptionally high rating of 18.36 million viewers due to its lead-in that Sunday night: Super Bowl XLII. Fox also had promotional spots advertising the show.  Season 1 fluctuated around the 8 million viewer mark. Season 2 saw a decline in ratings when the network moved the show to Fridays. Episode #14: "The Good Wound", premiered with the new timeslot, with viewership under 4 million viewers.
- Season 1 only aired 9 episodes due to the Writer's Strike
Season 1 vs. Competition (MON 9PM)
Due to the Writer's Strike, Terminator was one of the few scripted shows to air. Most other networks tried out new reality shows or aired repeats. NBC's Deal or No Deal was the winner in ratings on Mondays at 9:00 pm. Repeats of the half-hour comedy Two and a Half Men during the strike still did really well for CBS — it beat out all the other broadcast network's shows except Deal or No Deal. After airing repeats of Girlfriends for a while (and a repeat of Gossip Girl on 1/21), the CW debuted the reality show Pussycat Dolls Present: Girlicious on 2/18/2008.
- The pilot episode premiered on a Sunday (1/13/2008) and is not included in the chart.
- Also not included is the repeat on 1/28. The President gave his State of the Union Address on 1/28/2008 and Terminator aired a repeat of the pilot at 8pm before the speech.
- The 8th episode aired at 8pm (first of the 2-part finale) and is not included. The 9th and final episode that aired at 9pm is included.
- Dance War: Bruno vs. Carrie Ann ended its run on 2/18/2008
Season 2 vs. Competition (MON 8PM)
|FOX||Terminator: The Sarah Connor Chronicles [season 2 premiere]||09/08/08|
|ABC||Dancing With the Stars [season 7 premiere]||09/22/08|
|CBS||The Big Bang Theory [season 2 premiere]||How I Met Your Mother [season 4 premiere]||09/22/08|
|NBC||Chuck [season 2 premiere]||09/29/08|
|CW||Gossip Girl [season 2 premiere]||09/01/08|
When reality show Dancing with the Stars aired on Monday it dominated the ratings with at least 18 million or more viewers tuning in to watch the show.
- Blanks or gaps in the chart indicate that the show did not air an episode on that date.
Season 2 vs. Competition (FRI 8PM)
The timeslot at 8:00pm on Fridays, is dominated by the Ghost Whisperer. Terminator, a scripted show, has ratings nearly the same as the un-scripted reality shows Wife Swap and Howie Do It.
- Ghost Whisperer had a ratings dip on 02/20 due to it being a re-run.
- On 03/20 and 03/27 Ghost Whisperer did not air episodes due to 2009 NCAA Basketball (8.36 million and 10.31 million viewers).
- View the ratings data for all shows discussed in this article on the data subpage.
Terminator: The Sarah Connor Chronicles Season 1 Ratings Date Viewers 18-49 Episode ----------------------------------------------------------------------------- 01/13/08(S) 18.36 M 7.7 Pilot 01/14/08 10.08 M 4.2 Gnothi Seauton 01/21/08 8.66 M 3.6 The Turk 01/28/08(R-S 8pm) 5.99 M 2.2 pilot re-run 02/04/08 8.82 M 3.5 Heavy Metal 02/11/08 8.32 M 3.5 Queen's Gambit 02/18/08 8.10 M 3.2 Dungeons & Dragons 02/25/08 7.12 M 2.7 The Demon Hand 03/03/08(S-8p) 7.75 M 3.0 Vick's Chip 03/03/08(9pm) 8.29 M 3.3 What He Beheld
Terminator: The Sarah Connor Chronicles Season 2 Ratings Date Viewers 18-49 Episode ----------------------------------------------------------------------------- 09/08/08(SP) 6.33 M 2.4/7 Samson & Delilah 09/15/08 5.56 M 2.1/6 Automatic For The People 09/22/08 5.89 M 2.3/6 The Mousetrap 09/29/08 5.37 M 2.0/5 Allison From Palmdale 10/06/08 5.73 M 2.3/6 Goodbye To All That 10/20/08 5.02 M 2.0/5 The Tower Is Tall But the Fall Is Short 11/03/08 5.17 M 2.0/5 Brothers of Nablus 11/10/08 5.15 M 2.0/5 Mr. Ferguson is Ill Today 11/17/08 5.09 M 1.9/5 Complications 11/24/08 4.57 M 1.8/5 Strange Things Happen at the One Two Point 12/01/08 5.82 M 2.2/6 Self Made Man 12/08/08 5.25 M 1.9/5 Alpine Fields 12/15/08 5.07 M 1.9/5 Earthlings Welcome Here 02/13/09 3.71 M 1.4/5 The Good Wound 02/20/09 3.86 M 1.4/5 Desert Cantos 02/27/09 3.38 M 1.2/4 Some Must Watch, While Some Must Sleep 03/06/09 2.90 M 1.0/4 Ourselves Alone 03/13/09 3.39 M 1.2/4 Today Is The Day, Part 1 03/20/09 3.72 M 1.3/4 Today Is The Day, Part 2 03/27/09 3.87 M 1.3/4 To the Lighthouse 04/03/09 3.47 M 1.3/5 Adam Raised a Cain 04/10/09(SF) 3.59 M 1.3/5 Born to Run
Source: Nielsen Media Research via MediaWeek and TVbytheNumbers.com
Nielsen Television Ratings are gathered in one of two ways, both of them adaptations of the company's earliest methods. One involves the use of viewer "diaries," in which a target audience self-records its viewing (or listening) habits. By targeting various demographics, the assembled statistical models promise an accurate rendering of the audiences of any given show, network, programming hour, and the like. A more technologically sophisticated system has used Set Meters, which are small devices connected to every television in selected homes. These devices gather the viewing habits of the home and transmit the information nightly to Nielsen through a "Home Unit" connected to a phone line. Set Meter information is meant to eliminate subject biases and survey-response effects; scholarly literature has suggested that diarists change their habits to conform to their desired profile. The technology-based "home unit" system is meant to allow market researchers to more accurately study television viewing habits on a minute to minute basis, seeing the exact moment viewers change channels or turn off their TV. In addition to this technology, the implementation of individual viewer reporting devices (called people meters) has allowed the company to separate household viewing information into various demographic groups. While this system removes one form of bias, it cannot account for the presence of actual viewers in front of sets, i.e. the "empty-room syndrome" in which tvs play without active viewers. 
First let's talk about Fast/Final National Ratings Data from Nielsen Media Research. According to television resource site, The Futon Critic :
Nielsen collects data from two different samples: a "National Measurement" and a "Local Measurement." Households in each sample are given a device that tracks their viewing habits.
The 5,100 participating households in the "National Measurement" are outfitted with what's called a "Nielsen People Meter." This device measures two things - what program or channel is being watched and who in the household is watching. It accomplishes this by instructing each member in the household to press a button indicating that they have begun watching television on that particular set. This process allows Nielsen to electronically gather demographic information.Every night this data is transmitted to Nielsen Media Research's Operations Center in Dunedin, Florida. Around 8:00 a.m. EST the next day Nielsen releases the preliminary "fast national" ratings from this data.
The "fast national" ratings is what you see reported every morning on sites like The Futon Critic and Zap2It. Later in the afternoon around 3:00 p.m. EST Nielsen releases "final national" ratings, which you see reported in newspapers like The New York Times, L.A. Times and USA Today.
RATINGS DATA: "T:TSCC" (household: 6.2/9, #2, 10.07M viewers, adults 18-49: 4.3/10, #2)
Here is a summary of what those numbers mean:
- household rating = 6.2
- household share = 9
- household rank (for the night) = #2
- adults 18-49 rating = 4.3
- adults 18-49 rank (for the night) = #2
- 6.2 = T:TSCC's household rating, which indicates that 6.2% of all households in the U.S. watched this broadcast
- 9 = T:TSCC's household share, which indicates 9% of all households watching TV in the U.S. watched this broadcast
- #2 = T:TSCC's household ranking for that night
- 4.3 = T:TSCC's adults 18-49 rating, which indicates 4.3% of all adults 18-49 in the U.S. watched this broadcast
- #2 = T:TSCC's adults 18-49 ranking for that night
For more detailed explainations, the Ratings FAQ by The Futon Critic is recommended reading.
- ↑ 1.0 1.1 Nielsen Ratings
- ↑ 2.0 2.1 Numbers 102 by TVbytheNumbers.com
- ↑ Numbers 101 by TVbytheNumbers.com
- ↑ Nielsen definitions and explanations PDF by Nielsen
- ↑ DVRs give 'Dollhouse' nearly a third more viewers
- ↑ Dollhouse premiere is 28th in total DVR viewing, 8th in % viewing on DVR Contains DVR data for Broadcast TV Shows, February 9-15, 2009
- ↑ FOX Blog: boosting to success... help! Suggestion for viewers to help boost attention and ratings
- ↑ TNS Media Research FOX-TV Network Commercial Listing
- ↑ Futon Critic Ratings FAQ Recommended reading!