Nielsen's cross-platform crossing diagram crosses up readers
Aug 08, 2011
My friend Augustine F., who's a data-savvy guy, couldn't figure out what's going on with this chart in Nielsen's cross-platform report.
It's a case of a Bumps chart done poorly.
The reader must first read the beginning pages of the report to find one's bearing. The two charts are supposed to investigate the correlation between streaming video and regular TV. What causes the confusion is that the populations being analyzed are different between the two charts.
In the left chart, they exclude anyone who do not watch streaming video (35% of the sample), and then divide those who watch streaming video into five equal-sized segments based on how much they watch. Then, they look at how much regular TV each segment watches on average.
In the right chart, they exclude anyone who do not watch regular TV (just 0.5% of the sample), and then divide those who watch regular TV into five equal-sized segments based on how much they watch. Then, they look at how much online streaming video each segment watches on average.
What crosses us up is the relative scales. The scale for regular TV viewing is tightly clustered between 212 and 247 daily minutes on the left chart but has a wide range between 24 and 522 on the right chart. The impression given by the designer is that the same population (18-34 year olds) is divided into five groups (quintiles) for each chart, albeit using different criteria. It just doesn't make sense that the group averages do not match.
The reason for this mismatch is the hugely divergent rates of exclusion as described above. What the chart seems to be saying is that the 65% who use streaming video have very similar TV viewing behavior (about 220 daily minutes). In other words, we surmise that most of those people on the left chart map to groups 2 and 3 on the right chart.
Who are the people in groups 1, 4 and 5 on the right chart? It appears that they are the 35% who don't watch streaming video. Thus, the real insight of this chart is that there are two types of people who don't watch streaming video: those who watch very little regular TV at all, and those who watch twice the average amount of regular TV.
Here's another puzzle: Nielsen claims that high streaming = low TV and low streaming = high TV. Is it really true that high streaming = low TV? Take the segment of highest streaming (#1 on the left chart). This group, which is 13% of the survey population, accounts for 83% of the streaming minutes -- almost 71,000 out of 86,000 minutes. Now look at the right chart. It turns out that the streaming minutes are quite evenly distributed among those TV-based quintiles, ranging from 15,000 minutes to 23,000 minutes each.
So, it is impossible to fit all of the top streaming quintile into any one TV quintile - they have too many streaming minutes. In fact, the top streaming quintile must be quite spread out among the TV quintiles since each of the TV quintiles is 1.5 times the size of a streaming quintile!
So, we must conclude that customers who stream a lot include both fervent TV fans as well as those who watch little TV.
In a return-on-effort analysis, this is a high-effort, low-reward chart.
I think this is a case where using averages completely hides the underlying phenomena. It is necessary to do so much guessing (and your guesses seem different from mine), before you can even begin analyzing the situation.
Posted by: Jon Peltier | Aug 08, 2011 at 07:35 AM
This is what happens when a fine, noble marketing research organization hires too many PR people.
Posted by: zbicyclist | Aug 08, 2011 at 11:28 PM