Thursday, 14 August 2014

I am a power-tool A/B skeptic

I have recently enjoyed reading Peter W Szabo's article entitled, "I am an A/B testing skeptical."  Sure, it's a controversial title (especially when he shared it in the LinkedIn Group for web analysts and optimisers), but it's thought-provoking nonetheless.

And reading it has made me realise:  I am a power-drill skeptic. I've often wondered what the benefit of having the latest Black and Decker power tool might actually be.  After all, there are plenty of hand drills out there that are capable of drilling holes in wood, brick (if you're careful) and even metal sheet. The way I see it, there are five key reasons why power drills are not as good as hand-drilling (and I'm not going to discuss the safety risks of holding a high-powered electrical device in your hand, or the risks of flying dust and debris).

5.  There's no consistency in the size of hole I drill.

I can use a hand drill and by watching how hard I press and how quickly I turn the handle, I can monitor the depth and width of the hole I'm drilling.  Not so with a power drill - sometimes it flies off by itself, sometimes it drills too slowly.  I have read about this online, and I've watched some YouTube videos.  I have seen some experienced users (or professionals, or gurus, or power users) drill a hole which is 0.25 ins diameter and 3 ins deep, but when I try to use the same equipment at home, I find that my hole is much wider (especially at the end) and often deeper.  Perhaps I'm drilling into wood and they're drilling into brick? Perhaps I'm not using the same metal bits in my power drill?  Who knows?

4.  Power drill bits wear out faster.

Again, in my experience, the drill bits I use wear out more quickly with a power drill.  Perhaps leaving them on the side isn't the best place for them, especially in a damp environment.  I have found that my hand drill works fine because I keep it in my toolbox and take care of it, but having several drill bits for my power tool means I don't have space or time to keep track of them all; what happens is that I often try to drill with a power-drill bit that's worn out and a little bit rusty, and the results aren't as good as when the drill bits were new.  The drill bits I buy at Easter are always worn out and rusty by Christmas.

The professionals always seem to be using shiny new tools and bits, but not me.  But, as I said, this hasn't been a problem previously because having one hand-drill with only a small selection of bits has made it easier to keep track of them.  That's a key reason why power tools aren't for me. 

3.  Most power drills are a waste of time.

Power drills are expensive, especially when compared to the hand tool version.  They cost a lot of money, and what's the most you can do with them?  Drill holes.  Or, with careful use, screw in screws.  No, they can't measure how deep the hole should be, or how wide.  Some models claim to be able to tell you how deep your hole is while you're drilling it, but that's still pretty limited.  When I want to put up a shelf, I end up with a load of holes in a wall that I don't want, but that's possibly because I didn't think about the size of the shelf, the height I wanted it or what size of plugs I need to put into the wall to get my shelf to stay up (and remain horizontal).  Maybe I should have measured the wall better first, or something.
Measure twice, drill once.
2.  I always need more holes 

As I mentioned with power drills being a waste of time, I often find that compared to the professionals I have to drill a lot more holes than usual.  They seem to have this uncanny ability to drill the holes in exactly the right places (how do they do that?) and then put their bookshelves up perfectly.  They seem to understand the tools they're using - the drill, the bits, the screws, the plugs, the wall - and yet when I try to do this with one of their new-fangled power-drills, I end up with too many holes.  I keep missing what I'm aiming for; perhaps I need more practice.  As it is, when I've finished one hole, I can often see how I could make it better and what I need to do, and get closer and closer with each of the subsequent holes I drill.  Perhaps the drill is just defective?

1.  Power drills will give you holes, but they won't necessarily be the right size

This pretty much sums up power drills for me, and the largest flaw that's totally inherent in power tools.  I've already said that they're only useful for drilling holes, and that the holes are often too wide, too short and in the wrong place. In some cases, when one of my team has identified that the holes are in the wrong place, they've been able to quickly suggest a better location - only to then find that that's also incorrect, and then have two wrong holes and still no way of completing my job.  It seems to me that drilling holes and putting up bookshelves (or display shelving, worse still) is something that's just best left to the professionals.  They can afford the best drill bits and the most expensive drills, and they also have the money available to make so many mistakes - it's clear to me that they must have some form of Jedi mind power, or foreknowledge of the kinds of holes they want to drill and where to drill them. 

In conclusion:

Okay, you got me, perhaps I am being a little unkind.  There are a lot of web analytics and A/B professionals out there, but there is also a large number of amateurs who want to try their hand at online testing and who get upset or confused when it doesn't work out.  Like any skilled profession, if you want to do analytics and optimisation properly, you can be sure it's harder than it looks (especially if it looks easy).  It takes time and thought to run a good test (let alone build up a testing program) and to make sure that you're hitting the target you're aiming for.  Why are you running this test?  It takes more than just the ability to split traffic between two or more designs to run a test.

Yes, I've parodied Peter W Szabo's original article, but that's because it seemed to me the easiest way to highlight some of the misconceptions that he's identified, and which exist in the wider online optimisation community - especially the ideas that 'tests will teach you useful things', and the underlying misconception that 'testing is quick and easy'.  I will briefly mention that you need a reason to run a test (just as you need a reason to drill a hole) and you need to do some analytical thinking (using other tools, not just testing tools) in the same way as you would use a spirit level, a pencil and a ruler when drilling a hole.

Drilling the hole in the wall is only one step in the process of putting up a bookshelf; splitting traffic in a test should be just one step in the optimisation process, and should be preceded by some serious thought and design work, and followed up with careful review and analysis.  Otherwise, you'll never put your shelf up straight, and your tests will never tell you anything.

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