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iTunes and the 80-20 Rule

The “80-20 Rule” — you often see it cited in discussions of software usability, usually in support of calls for simplifying complex apps or for breaking them apart. I most recently heard it come up in the entertaining and informative discussion that Kirk McElhearn and Chuck Joiner had in a recent MacVoices interview about Kirk’s “Take Control of iTunes 12: The FAQ.”

At issue was the ever-expanding feature set of Apple’s iTunes, which, with the addition of Apple Music and Beats 1, has become increasingly difficult for users to use and navigate, turning it into what Marco Arment colorfully described as a “toxic hellstew” (a phrase he may have borrowed from Apple CEO Tim Cook, who once used it to describe Android). Kirk brought the rule up to drive home the point that most iTunes features are not used by most iTunes users, and that the app could use a complete overhaul to make it more manageable and accessible.

But what is the “80-20 Rule” to which Kirk referred? Lately, it has come to mean something like this: “80 percent of an application’s users use only 20 percent of its features.” Lurking behind this “rule” is the idea that developers could make apps far easier to use and far more reliable if they devoted their time to clarifying and optimizing the 20 percent of features that the 80 percent of users most often use.

Like many such rules, such as “wait 30 minutes after you eat before you go swimming” or “never go in against a Sicilian when death is on the line,” there is a kernel of sense behind the rule: some studies have shown that, for many systems, a large percentage of functions are seldom, if ever, used. But the systems in those studies tend not to be widely used consumer apps but those being developed for specific business or engineering purposes, and the studies are mostly interested in examining how to get the most bang for the in-house development staff’s bucks, and are not concerned about usability.

In any case, widely used consumer apps — and by “widely” I’m talking about apps used daily by millions of users — are rather different creatures than, say, an enterprise’s in-house inventory control and management system that might have only a few hundred users at most.

In fact, the original “80-20 Rule” was not a rule at all, but an observation by 19th-century Italian economist Vilfredo Pareto, who noticed that 80 percent of Italian income was received by 20 percent of the Italian population. It was promoted to a “principle” by Joseph M. Juran in 1941, who suggested that most results in any situation are determined by a small number of causes.

All of which is to say that the “80-20 Rule” is really just an observation, and one that has less to do with usability than with the effort involved in developing and debugging complex systems. Nor can you rely upon the magical 80-20 ratio: depending on the app and the user, it might be 95-5, or 60-40, or some other ratio. 80-20 is only a ballpark figure, and the ballpark dimensions themselves vary from team to team and from sport to sport.

I have little doubt that any one iTunes user is apt to use only a small number of the many features that iTunes offers. The problem is that, for iTunes as for any app, you cannot assume that the small number of features used by one user are the same features as those favored by another user.

In addition, the very idea of a single “user” as some sort of Platonic ideal creature whose needs you must meet to have a successful app won’t get you very far when it comes to making an app usable. Most usability analysts worth their salt don’t even envision a single user at all. They often develop a variety of “personas,” imaginary folk who come with specific needs, goals, backgrounds, and tastes, and they look at an app’s feature set and implementation in terms of each of those personas.

What’s more, when it comes to usability testing, analysts try to match actual test subjects to one or more of those personas: test results are seldom considered reliable if the tests don’t encompass a range of different users that match the range of personas. Nor are the analysts’ personas themselves cast in stone: they, too, are developed and expanded and refined as more information about real living, breathing human users of a product is acquired.

Usability analysis, in short, is a complicated blend of science and art, and applying it reliably to any particular app is usually fraught with caveats. And the larger and more varied the population of users of that app, the more difficult it is, and that is even when you don’t consider the business goals that the app must also meet for it to be considered a success.

Kirk, in the MacVoices interview, wisely employed the “80-20 Rule” only to illustrate how users might find the bevy of features offered by iTunes confusing, and he smartly acknowledged that coming up with a list of substantive suggestions that would finally “fix” iTunes to the delight of users everywhere, given how many different user needs it has to meet, was beyond him.

It may be beyond Apple as well — iTunes has seen significant user interface changes in each of its last three major incarnations, a level of variability that has generated its own confusions. That is not to say, of course, that Apple shouldn’t keep trying: the company’s $200 billion cash pile could certainly pay for a lot of formal usability analysis and careful engineering. However, simple rubrics like the “80-20 Rule” are not apt to get the company very far in such an effort.


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Comments about iTunes and the 80-20 Rule
(Comments are closed.)

Michel Hedley  2015-08-01 09:06
There is enough research to show that the 80-20 rule is viable in a number of constructs - e.g. input/output; value/non-value; benefit/cost; etc. When I apply the rule to my own use of iTunes, the rule works rather fittingly. Possibly iTunes is carrying too many saddles. If iTunes could be customised a bit, then it might suit more users.
Michael E. Cohen  An apple icon for a TidBITS Staffer 2015-08-01 12:14
It's not that the rule is not viable, but that it is not particularly revelatory. Which features? For which users? In which circumstances?

As for applying it to your own experiences with iTunes (or any other app), keep in mind that the first lesson that every usability analyst has to learn is this: "You are not the user."
robmorrison  2015-08-03 20:21
iTunes is definitely less user friendly than it was a few generations ago. The same is true for many of Apple's apps, like Pages, Maps, Safari. Useful features disappear and very often useless features are added. Remember the loss of "Save As"? Does Apple even ask its customers what they like or don't like? It seems that they do not.
dmacmitchell  2015-08-03 21:54
This article was disappointing. In summary: iTunes is a "toxic hellstew", 80-20 rule research, we don't know how to fix it, but we hope apple keeps trying.
Adam Engst  An apple icon for a TidBITS Staffer 2015-08-04 09:28
The point is merely that the 80-20 rule that keeps being cited as something that would help Apple figure out how to "fix" iTunes isn't nearly the panacea that pundits seem to think it is.
Strikes me that iTunes has followed in the footsteps of Microsoft products, most notably Word and Excel, to our detriment. These two are arguably the most powerful apps in their fields, but why have to jump through all those hoops to get done the simple tasks most of us need? (MS has actually acknowledged this issue with the WordPad app.) Wouldn't it be better to break iTunes up into different apps, each focusing on specific functions. Now that I think about it, this has already happened in the case of iBooks. Keep it up, Apple!
Adam Engst  An apple icon for a TidBITS Staffer 2015-08-04 09:29
And, in fact, this is exactly what Apple has done in iOS, where there are Music, Videos, Podcasts, iTunes U, iTunes (Store), and iBooks apps.
Ian Wolf  2015-08-04 15:09
Expanding on Bill's comment and Adam's reply, one of the logical (to me ad least) functions that could and should be split out of iTunes is it's managing of iOS devices . This new program would do all the sync, backups and management of apps etc. for your iPhone, iPad, Apple Watch and possible iPods that now takes place under iTunes. This would leave all the "entertainment" functions and their management as something closer to what the original iTunes started life as. You could call the new program something like, "iOS Apps Utility Tool". The result would be two simpler and more usable apps.

Right now iTunes reminds me of that old SiFi movie, "The Blob." This big massive blob that is forever growing and absorbing everything around it. Well it's time to cleave "The Blob" that is iTunes into smaller and more manageable blobs. But I have no doubt that in a decade or less the smaller blobs will themselves have grown into massive beasts once again. Such is life and apparently the life of programs as well!
John (JD) Denning  2015-08-18 11:48
I cringe when I hear talk of iTunes being too big, bloated, and needs to be broken up. The size, and even complexity of tasks isn't the issue. The issue is the interface.

Apple works so hard to make something simple that they actually make it difficult to learn, and use.

I want a one stop app for all my IOS devices to sync to, and manage all my media, including Podcasts. I don't want to have 5 applications open where one would do. But darn it, make a good interface. Make it customizable, maybe turn on, and off, features. Like if one cares nothing for Movies, just disable that tab.

I don't get Apple Music, does nothing for me, But I don't care that it's there. I just don't use it.
I agree entirely with the notion that iTiunes has started to resemble MS Office. A beheamonth of a package that attempts to cater to every special interest while missing to do effectively what most of the people would want to use it for most of the time.

Nevertheless, I don't think it's a wise idea to split it up for several reasons. I believe you can imporve iTunes substantially without splitting it up.

Take simple navigation. iTunes used to have one sidebar and one window pane with (a list of) content. Simple but effective. Why not use that paradigm to handle the myriad of parts of iTunes that often have little to do with one another directly (like iOS device syncing vs. iTunes U content). I'm afraid that was sacrificed because it didn't look "modern" or feel "cool". But heck, it works. Spice up the graphics if need be, but don't break something simple that works.
George Istvan  2015-08-04 16:26
I would like to see an iTunes-Lite. Apple can retain its regular version if it thinks it has to impress some people with a MSWord-like behemoth. I'm happy with my Tiger version of iTunes. Sometimes less complicated is much better.
xandra  2015-08-04 17:29
The 80-20 rule is about the last thing I'd want to see.

The 20% would surely remove: lyrics, smart playlists, applescript capability, format conversion, change MP3 meta-tag versions. Heck possibly even kill off burning/importing CDs. Multiple windows was the first casualty of this approach.

I think Simon's comments were right on target: the problem isn't the quantity of features but their chaotic (and endlessly changing) presentation.

Heck some basic GUI improvements would do wonders: why doesn't "Music" (icon on top, word in sidebar) change color when its selected., why does "My Music" insist on displaying album covers - if that's what it is, it should be NAMED Albums. I could go on... I personally think the removal of color was one of the biggest errors: don't believe me, check out the subways in DC. Really odd from the Company that figured out how helpful color was as a GUI element in an interface.

Apple is clearly is interested in bringing income producing features to the forefront. I can't blame them for that and I think thats only a small part of the problem, but they need at least do a better job. Was there really a point in removing the "Search" menu item from the Store menu?

There was a statement quoted recently (I think actually in Tidbits) to the effect of "iTunes can't live with it can't live without it" For one I PREFER to have all/most media needs handled in one place. And in the end, I haven't found a vaguely close replacement on either platform.

I'd like to see Apple clean up the interface BIG TIME - without removing features. Test it on folks of various levels then STOP changing everything with each update.
Jim Heartney  2015-08-05 18:28
Steve Jobs was rather good at dumping obsolete functionality from his products (often to howls of protest), and in many cases time showed the wisdom of his decisions. If he were still here I imagine he'd have longs since taken a cleaver to iTunes, probably in ways we couldn't imagine.

I'm old enough to remember Apple's non-Steve interregnum (1985-97), and the way its offerings became needlessly complex and unfocused. It's sad to see the same thing happening again now. iTunes is looking more and more like something from the Spindler/Amelio era.