|How I Met Your Mother||10.14||3.9||49%||-13%||n/a||-13%||13/13||-11%||n/a||2.77|
|2 Broke Girls||12.10||4.4||47%||+5%||-7%||-7%||9/13||-4%||+13%||3.76|
|Two and a Half Men||13.94||4.5||41%||-4%||+33%||-24%||13/13||-24%||+2%||3.81|
|Mike and Molly||11.90||3.8||41%||-5%||-4%||-9%||11/12||-14%||-16%||3.23|
There are ten numbers for each rating result. Here's what they all mean:
Viewers - From Nielsen. The total number of viewers (age 2+, in millions) that watched the program. Though this number has a dubious correlation with renewability and advertising rates, it is the most easily accessible TV ratings number. Since I'm sort of turning this blog into a massive ratings archive this year, I think this number should be included even if I'm not really going to "use" it.
A18-49 - From Nielsen. Adults 18-49 rating. Percentage of US TV-owning adults 18-49 watching the program. This is the most common currency for TV ratings these days. For more on why I use this and not total viewers, I recommend the Intro to Nielsen Ratings and the Peetooplus project.
Share - From Nielsen. Adults 18-49 share. Percentage of US TV-watching adults 18-49 watching the program. This number on its own is even less useful than it used to be because it is not calculated using the same methodology as ratings. For more on that, see this portion of my True Strength project from last summer. While I've made some adjustments in the True Strength project to counteract some of that, what I present here is just the raw share number Nielsen provides. Update (1/5/11): For full tables effective 1/2/12, I'm no longer including share to make room for the Tavg number described below. Sorry if this is an inconvenience, but there has been no indication to me that anyone outside of me cares about them. The shares will still be available for eligible shows in the SpotVault, and the SpotVault covers almost everything.
Skew - Calculation. Percentage of the total audience that falls in the 18-49 demo. It's not hugely helpful on its own, because advertising rates correlate more closely with raw A18-49 ratings than with "skew." However, shows with a higher "skew" tend to bring in more advertising bang for their A18-49 buck. Though I don't include (or regularly have access to) similar demos like adults 18-34 and adults 25-54, the skew can be a decent way of getting a very general idea of those demos. Shows with very high skew typically perform well in adults 18-34 relative to their 18-49 rating, while shows with very low skew typically perform well in adults 25-54 relative to their 18-49 rating.
Last - Calculation. A18-49 percent difference from previous episode. This has become sort of the standard-issue number in the great race to make daily ratings interesting. I'm not quite as entranced with it as some, because I think most individual fluctuations are fairly meaningless and boring, and quite a few are misleading, but it's still a pretty reliable go-to way of explaining what happened last night.
LeLa - Calculation. A18-49 percent difference between the show's lead-in and its lead-in for the previous episode. Typically, if the listings are the same as last week, you can just look to the "Last" of the program above it to get this number. This number is at its most useful when a show has a drastic change in lead-in. It's meant to be used in tandem with "Last" as a possible explanation for week-to-week fluctuations.
Avg - Calculation. A18-49 percent difference from the show's average demo for previous original episodes this season. A nice thing to have because, as noted earlier, the "Last" stat which has so permeated the daily ratings narrative can often be misleading. ("Steady" at a series low is not really an accomplishment, while calling something "down" when it loses one tenth from a big spike to a series high also kinda misses the point.) I understand that the "Last" thing is probably the best way to make this stuff interesting week-to-week, but this is sometimes the more correct story within the context of the show's previous ratings. (But "Avg" can be unhelpful in its own right at times; for example, shows typically decline in the spring meaning lots of well-below average episodes. That's not "bad" for the shows per se, just natural.)
Rank - Calculation. The A18-49 rating's rank among the show's episodes that have aired so far this season. Basically the same as Avg, a way of comparing it against the rest of the season. Since it doesn't denote ties, it may not be clear if it's a "15/16" whether it tied a season low or is actually the second-lowest number. Not sure how to elegantly fix that and still make it fit in the space. Sorry. But hey, you can rest assured that "16/16" is definitely an outright season low.
UPDATE (1/5/11): Tavg - Calculation. A18-49 percent difference from its timeslot's previous average for programming of the same type this season. I'm introducing this number at the beginning of midseason to help give some sense of how the midseason scheduling changes are working out compared to previous timeslot occupants. In order to optimize this number, I only compare the rating to other programming "of the same type." What does "of the same type" mean? For this number, I've broken all programming into two types: "Original" (all original regular and sports programs) and "Repeat" (all repeats plus all movies and specials). That means original specials and movies are technically in the "repeat" column, at least for now. Not sure if those two types are the best arrangement, so I may tweak this one later.
Lead - Calculation. A18-49 percent difference from lead-in program. Though this number (or the similar "retention") weren't used in the True Strength project last summer, I did in that project demonstrate that shows are pretty reliably affected by the size of their lead-in. Shows that drop significantly from their lead-ins may not be as "truly strong" as their ratings appear.
TRUE - Calculation. True Strength, a metric developed last summer that adjusts the A18-49 rating for overall viewing levels, competition and lead-in. Trying to explain it any more than that is probably hopeless without writing pages upon pages, so I'll just point you to the intro for the general purpose of the number and the summary of the process for more of the deets on how I arrived at this number. All Monday to Friday TRUE numbers in daily posts (and sometimes Sunday) are PRELIMINARY True Strength and are recalculated next week as I get half-hour info. The FINAL True Strength (available in the upcoming SpotVault feature) is on average about ±5% different from the prelim.
You'll notice three of the numbers from last year's version are gone, those being Competition, CoLa (competition vs. the competition for the previous episode) and bcShr (the rating as a percentage of all the show ratings in the timeslot). Also leaving are the daily viewing level tables. Though I still care quite a bit about those numbers, they get the axe because I really want to make everything on the nightly posts "right." None of the numbers on the current table (except for True Strength, which I spent too much damn time working on to cut out!) are affected by my lack of access to half-hour breakdowns. These are relatively absolute. This will avoid me having to write a dissertation of fine print after every table.
But never fear; the upcoming SpotVault updates will have competition and viewing levels which will be considerably more accurate, and I suppose if you really want that information for every single timeslot on TV you could probably visit several pages in the Vault and piece it together. I might eventually come up with some kind of quick post every week that looks at the overall viewing levels.