Picking Productive Pareto Portion Problematic

Over at the blog of statistician John Cook is a thoughtful post about the Pareto Principle (aka, the 80-20 Rule) that explains the rule, counters common objections to it, and discusses some of the difficulties in applying the rule. As an example of the latter, consider Cook's discussion of how simple ignorance can get in the way. He first tackles this in answering a common objection to the rule:

Image of Vilfredo Pareto via Wikipedia.

A final objection is the ignorance argument: we simply don't what the most effective 20% will be beforehand. This is a serious objection, and it should temper our optimism regarding the Pareto principle. If a salesman knew which 20% of his prospects were going to buy, he should just sell to them. But of course he doesn't know ahead of time who those 20% will be. On the other hand, he has some idea who is likely to buy (and how much they may buy) and doesn't approach prospects randomly.

These objections take the Pareto principle to extremes to justify disregarding it. Since you can't repeatedly apply it indefinitely, there must be nothing to it. Or if you can't completely eliminate the least productive work, you should treat everything equally. Or if you don't have absolute certainty regarding what's most important, you shouldn't consider what's likely to be most important. [italics and first bold in original, second bold added, link omitted]

Cook continues his line of thought in his section on application:

I mentioned ignorance above. "Uncertainty" is a more helpful word than "ignorance" here because we're not often completely ignorant. We usually have some idea which actions are more likely to be effective. Data can help. Start by using whatever information or intuition you have, and update it as you gather data.

This is great advice, and Cook is spot-on about being honest with ourselves about how effective we want to be.

All I might add is that we might need to remind ourselves and others that appearances can be deceiving at certain stages of a project. Right now for example, I am engaged in a long-term plan to make it easier to keep the house clean. A consequence of this is that, for a time, the house is going to look even messier than it usually has, because repeatedly straightening the kids' messes is less effective than dumping or donating a backlog of old toys and unpacked boxes from our last move. (In my case, tripping over a toy serves as a reminder to myself of this goal, as well as a prompt to remind others of it.) With that done, though, I will be able to move to the next part of my plan, which is to use my newly-available storage space in the basement to store toys I think the kids have outgrown or never really liked. This will give us less to deal with at cleaning time and simplify the task, not to mention make it easier to just get rid of forgotten items after a time.

-- CAV