Showing posts with label Nate Silver. Show all posts
Showing posts with label Nate Silver. Show all posts

Friday, October 30, 2015

World Statistics Day, Back to the Future, and the "Signal and the Noise" of TSL

Last week was a geek-fest.

First, World Statistics Day on the 20th and then “Back to the Future Day” on the 21st.  For me, last week also included an in-depth, somewhat geeky discussion with a station about Time Spent Listening.

That was a trifecta that begged for a blog.

While World Statistics Day didn’t go completely unnoticed, we were tripping over pieces on BTTF2 predictions that did or didn't come to pass.

The focus on predictions, statistics and the TSL discussion reminded me of an excellent read from a few years back: Nate Silvers The Signal and the Noise: Why Most Predictions Fail – But Some Dont. It's long on everyday examples from weather to baseball to poker and more. It's deep enough to be challenging (especially if you're like me - a non-statistician who like stats) yet it's not so deep that youll drown.


Statistics play a role in most businesses; they certainly do in radio with ratings at the forefront for most programmers. 

Part of a consultant’s job is to provide the greatest understanding of the factors that impact/impacted ratings – not just to explain what happened, but to predict and recommend what changes (if any) could lead to better results.

The examination of ratings data is often the process of separating the signal from the noise: what factors were the primary drivers and what factors were ancillary or irrelevant.

To inspire you on your next analysis (ratings or otherwise), here are few quotes on signal and noise from Nate.



“Immersion in a topic will provide disproportionately more insight than an executive summary.”

If you really want to understand something, you’re likely going to have to spend time under the hood. 

That’s not a new thought of course, but a good reminder that – especially where ratings are concerned – the deeper you dive, the more you’re likely to discover.

Silver suggests using past as well as collective experiences to form probability theories before diving into data.

"The Bayesian approach toward thinking...encourages us to hold a large number of hypotheses in our head at once, to think about them probabilistically, and to update them frequently when we come across new information that might be more or less consistent with them."

Armed with a list of as many possible factors/scenarios that could have contributed to the outcome allows you to “stop and smell the data” which, Silver says, leads to better decision making - the reason you’re doing the deep dive in the first place.

A case in point was the Time Spent Listening discussion. The rise or fall of TSL may be related to your most obvious on air components like music, commercial load, or talent.  But it's also very possible that any of the other 13 variables associated with TSL could be major factors, including 100+ QHR diaries, format partisans in the sample, weighting, how early your first cuming occasions occur, etc.

Before jumping to a conclusion about what drove an increase or decrease, examine each variable your scenarios suggest and determine 1) whether or not that variable was a factor and, 2) if so, to what degree.

As you work your way through the data, new information may challenge or strengthen your original assumptions.

As it turns out, the TSL drivers in the station discussion last week did ultimately prove to be something different than the original hypothesis. 



“Information becomes knowledge only when its placed in context. Without it, we have no way to differentiate the signal from the noise…”

Trending data is a quick way to add context. Compare not only your most recent performance to past performances but also format averages, audience composition, sample, and any other relevant data.

As Silver notes, “most of the time, we do not appreciate how noisy the data is, and so our bias is to place too much weight on the newest data point.”



And about those times when, to the best of your knowledge you did everything right, yet the outcome was disappointing?

“…sometimes the only solution when the data is very noisy – is to focus more on the process than on results…Poker players tend to understand this more than most other people…Play well and win; play well and lose; play badly and lose; play badly and win: every poker player has experienced each of these conditions so many times over that they know there is a difference between process and results.”

Focusing on the process isn't a “pass.” Instead, it’s an opportunity for self improvement and a review of the procedures that have been associated with success over the long term.


Bottom line: the next time you’re working through a report, seek to eliminate the noise by:


  1. Committing the time it takes to do a deep dive
  2. Creating multiple theories about what might have driven the results and a corresponding checklist of data to examine
  3. Evaluating and providing context for all the data relevant to your theories
  4. Review the process with an eye toward self-improvement 


As Nate points out, "Good innovators typically think very big and very small. New ideas are sometimes found in the most granular details of a problem where few others bother to look...sometimes we let information that might give us a competitive advantage slip through the cracks."

Wednesday, January 30, 2013

When the Ratings Are/Aren't What You Expected: A Process for Uncovering What's Important

Ratings data is noisy.

Along the pathway to “is this real?” meaningful data rests alongside the spurious or even potentially misleading.

And usually when those results are better or (fortunately less often for our stations) worse than expected, there are questions.


Also usually within the data there are some (but likely not all) answers.

You'll increase your changes of finding the meaningful when you have a plan before going under the hood.

Use your ratings data and knowledge of what happened at your station and in the market to develop a list of as many possible scenarios that could be contributing factors. This list will direct you to specific areas of inquiry. It will also help give your investigation focus while still allowing you the freedom to go down some rabbit holes without the fear of getting hopelessly lost or sidetracked. 

Let’s look at one example – a big TSL swing – and some possible scenarios:
  •  There was real change in usage because of something that changed on the station
  •  There was a real change in usage not because something changed on the station but rather in the market or on a competitor
  • There were more/less heavy radio users, regardless of format, in the sample with overall usage that deviated from the norm
  • There were more or less heavy users of your format, station or a competitor’s station in the sample
  • There was a change in the demographic composition of the sample overall or in the sample of your format’s lifegroup
  • Proportionality was/wasn’t an issue
  • Geography/zip code returns was/wasn’t an issue
  • There was a significant change in the percent of employed fans of your station who are in the sample
  • There was a change in occasions of listening or in vertical or horizontal cuming (revisit bullets 1-5)
  • There was a single or handful of respondents that skewed a particular cell
  • There was a station identification issue (diaries) or a crediting error

Some of the above bullets can be assessed with relative ease, but others require more investigation, time, and a strong working knowledge of your ratings analysis software.  Regardless, getting a handle on the ‘degree of truth’ in your theories will go a long way in providing insight (of course you'll want to develop a different line of hypotheses for other issues).

Wading through ratings data is time consuming and some of your efforts won’t lead anywhere (we did say the data is noisy). But if you're going to get as much of a handle as you can on things, you'll need to do a deep dive. Having a plan helps.

And yet, even with as much noise removed as possible, conclusions may still be a bit murky. Sometimes we’ll need to call on the recent past to help us interpret what we’re seeing and give us guidance for the future.

But finding and then spending time with the critical information will increase the probability of being closer to the truth.

Two quotes from Nate Silver’s “The Signal and the Noise: Why Most Predictions Fail - but Some Don’t” sum things up pretty well:

“…immersion in a topic will provide disproportionately more insight than an executive summary.”

And,

“…success is determined by some combination of hard work, natural talent, and a person’s opportunities and environment – in other words, some combination of noise and signal.”


PS - “The Signal and the Noise: Why Most Predictions Fail - but Some Don’t” is an excellent read if you live in a world where data-driven assumptions, reporting and forecasting are a way of life - or if you play poker, bet on sporting events, or simply watch the local TV weather casts. Finishing the book at a time when such a large amount of ratings analysis is going on here at Albright & O'Malley & Brenner inspired the camera angle for this blog.