Survey: 6 percent of U.S. teens own iPhones
Who are these kids?
According to a Piper Jaffray survey of high school students released on Tuesday, 6 percent already own an iPhone and 9 percent expect to buy one in the next six months. That's twice as many teens as owned iPhones in Fall '07, three months after the device was first released, when 3 percent had already bought one and 9 percent planned to.
Overall, Apple (AAPL) did well in the survey, which sampled 389 U.S. teenagers and showed the company's lead rising in this key demographic.
iPod market share among the group was a record 86 percent, up from 82 percent last fall. And among the 39 percent who legally purchase music online, 81 percent said they used iTunes. That's actually down some from the 89 percent who used iTunes a year earlier, but it's not too shabby considering that a majority of the teenagers in the survey download their music from P2P services rather than paying for it legally.
Piper Jaffray analyst Gene Munster, the lead author of the report, surmises that Apple's share of the legal download market may be falling among teens despite their strong preference for iPods partly because other online music stores are selling DRM-free music that is compatible with the iPod. We assume he's talking about Amazon.
In any event, the survey shows that despite slowing sales for, say, fashion and footware, U.S. teenagers — or at least 6 percent of these 389 teens — still have money to spend at the Apple Store.
A sample of 384 that has 6% as the sample statistic produces a 95% confidence interval of from 3.6% to 8.4%, not 1% to 11%. if the sample had been of 1500 teens, that would have reduced the interval to 4.8% to 7.2%. Quadrupling the sample size halves the interval. The comments that question the selection method for those in the survey are much more relevant than questions about the sample size. It takes a pretty big sample to get the margin of error down below =/- 1% for a 95% confidence interval. This from a statistics instructor.
Steve from CT appears to be correct that the margin of error here appears to be +/-5%. As stated here, you don't need a huge or large sample base to create a statistic but if you want reliability and accuracy, the larger the sample the better. With a survey saying 6% own iPhones and there's such a large margin of error like there is here, it's nearly meaningless and certainly doesn't really tell us anything we didn't already know. We know teens have iPhones…we still have no idea how many own them. Another point is that as close to the original report that I've seen on this used the term "high school students" and also "teens." If there are 26M teenagers, then fine. But the U.S. DoE says there are 16.4M high school students. To me it's a moot point. Choosing a population of 16.4M vs an input of "infinity" comes out identical when plugging in the sample sizes and the 95% confidence level, etc. The sample is too small to give reliable results. I haven't seen the original report but what's been reported doesn't include even the margin of error. That's a "no-no" for reporting survey statistics in the news. Without that info being transparently reported by those releasing the data, the survey should be trashed. (it is possible that the full report gives that info…if so…why is it absent in the public form?…seems possible that the large margin of error would have not have attracted much attention from those seeking useful information)
Sample size accepted, but, is the sample a representative sample of the population. Does it cross economic, location, etc. lines to cast a broad net in obtaining the sample? Or is it concentrated in an economic niche that would generate the result give?
If you calculate the sample size based on a population of 20million with a confidence level of 95% and a confidence interval of 5…the sample size needed is 384. Based on this calculation the authors should have stated that were are 95% confident that 6% of US teens own an Iphone +/-5% (1% to 11%). I work as a market research analyst and I am very comfortable with calculating sample sizes.
I hope I read it wrong, but it seemed to favor Apple in this article as an advertising promotion. Anyone got paid from Apple?
A survey is only a survey and it seems to leave out the logistics of the survey. I am only surprised that CNN would post something like this.
No surprised that the younger crowd goesfor the Iphone since they've already got the Ipod, etc. It would be a natural customer base for Apple products. But since most teenagers depend upon their parents to obtain phones (like my boys), I would anticipate the percentage of teenagers that have cell phones that are not Iphones would dwarf the 6%.
While 389 is a sample survey, and it can reasonably justify a larger trend across a population (statistically speaking), it should be noted that a small sample group correlates to higher sampling errors. When the sample group size approches the population group size (i.e. teens in the U.S.), in theory this should bring the sampling error to near zero or to zero if testing the entire population. So, in effect the numbers the researcher is finding are not inaccurate, they are just not telling the whole story. I would say that the reason 6% doesn't add up to the actual U.S. teen population is due to a sampling error. In this case due to a variety of variables that are more than likely not factored (rural, urban, city, suburb, age, etc.). This in effect creates a ridiculous sampling error. For this reason I would have a hard time buying into what this says.
It is not surprising to me that many teens bought iPhones – considering how many have jobs after school/on weekends. My wife is an 11th grade teacher in a middle-income district, and the kids eerily reflect this statistic almost to the percentage point. More want to buy the Touch, but paying for the monthly $60 iPhone bill is no sweat…
The title is misleading. It should state 6% of surveyed teens owns an iPhone. 389 sample size is insufficient. Also where's the details of the sampling; location of survey, city/suburb, and any other possible criteria that may affect the sample size.
For those that say 6% would equal more than 10 mil, you need to go back to basic algebra….using X as total teens in US:
X(.06)=10,0000,000
There would have to be over 166 million teenagers in the United states for 10 million Iphones sold if it's 6% of teenagers.
If there's about 28 million teens like one person said, that would equate to 1.68 million teens owning the Iphone if you say 6% own one….which all seems like more reasonable numbers.
Let's just take a lowest number of US teens, 25 million.
6% of 25 million is 1.5 million.
If we're at 4.5 million iPhones sold, so PED is reporting 1 out of 3 are owned by the teens. Seems a little high to me.
Then again, what do I know, since I still reading this BS here.
What demographic were these teens? Were they all at the same high school, in a certain demographic area, or was the survey spread out across a larger area? If you surveyed teens from all 50 states, and represented different demographics, then yes, this would be a valid survey, representative of all U.S. teens, albeit with 389, the MOE wouldn't be the greatest, but nevertheless it would be a valid survey.
If 6% of teens actually already own an iPhone. Apple would have already sold more than 10M units a long time ago.
Since I have been in my Statistics class, I have been more prudent on articles such as this that claim "X percent of U.S. do blank"…… Can this article really claim, with validity, that "6 percent of U.S. teens own iPhones? There was only a small sample(389), compared to the entire U.S. teenager population, and was it a Simple Random Sample? This article seems to be misleading as a whole because of these preceding facts.
this is ridiculous a survey with 389 teens ? when there are approx 25 to 28 mil teens in the us according to the us census..that is in no way a big enough representative sample
where are these teens from ? the northeast ? mr munsters kids school ? or a mall in nj ? is this a good sampling across geographic and socio economic groups ?
this is such irresponsible reporting
Yes, a good college statistics course will teach you it doesn't take an awfully large sample group to obtain reasonably accurate results.
Um…yes…389 teenagers would be a survey. That's pretty much what a survey is…questioning a small sample to determine trends in a larger population, in this case, teenagers. If they'd asked non-teenagers, it wouldn't have been a valid survey of teenagers, now would it? What's your actual concern??
Even the author misinterpreted the numbers when he facetiously said, "…or at least these 389 teens — still have money to spend at the Apple Store,". He forgot that it is *6%* of 389 teens (or so says the "survey").
ex ped: Good catch! Fixed now. Thanks.