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Comment by dathinab | Hacker News Reader

The problem with "data driven" approaches is that they often miss the context.

Which can make their results absolute garbage.

Like data driven can tell you a button is "not used often" it can't tell you that a button is "essential to be fast available in some safety critical situations". (Or for other examples, that a feature is not unused because people don't want it but because it's hidden or bad designed.)

But somehow I still meat people which believe that poorly data driven approaches will yield the best results, which as far as I can tell is complete unrealistic. (Which doesn't mean in any way you shouldn't also use data for decisions, just be aware that data just shows a part of an picture and can often be very misleading.)

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Our customers don't use airbags often so we removed them to cut the costs.

The pilots never use the eject handle, so we made it smaller and moved it further under the seat.

This reminds me of my ex gym. About a year ago they put counters on all the machines. After some time they decided most of the machines were not used often enough and should be removed to expand the free weight section (which was comapritavely busy). What the didn't account for was the free weight section was essentially busy with the same set of people who spend all their time at the gym for heavy training.

Myself and quite few others who come by themselves to the gym more infrequently andwere using the machines (you need a spotter for the same exercises on the free weights). Now both groups paid the same for membership, but they essentially removed the ability for one group to train, needless to say I moved to a different gym. By blindly following the data they optised for worse customers (you want people to subscribe but not show up often).

> By blindly following the data they optised for worse customers (you want people to subscribe but not show up often).

There are other considerations. If it costs a lot more to have someone using the machines than to have someone using the free weights, you might be better off with just the free-weight crowd than you are also having the intermittent machine guys. You want customers that are profitable, which isn't the same thing as customers that only rarely show up.

Err... what? Gyms literally live off the customers that just go once in a month or directly never show up. They are dimensioned taking this into account, and they charge factoring this in. If 100% of the customers were body-builders using free weights, they would have to charge them at very least 2x.

My take is that the gym changed course, and instead of having half ghost customers who only reluctantly pay, they choose to go for heavy users who will take space, but also book coaching sessions, buy products and are more than willing to put the money on the table.

If it's really what happened I'd see that as a pretty great move.

>were body-builders using free weights, they would have to charge them at very least 2x.

At same spaces, yes! Good quality barbells and weights, while expensive, keep for over 30 years. Bodybuilding and powerlifting doesn't take much space, so you don't need a large space, and the customer base is dedicated and can often tolerate their gyms being a bit out of the way. Machines, however, like to break and are incredibly expensive compared to barbells and weights.

It isn't about the customers never showing up, it is the machines taking up space on the floor, unused 90% of the time, which stops more of the free-weight crowd from joining because the gym is too crowded.

When people want to join a gym they ask the fit guy which gym they recommend. It's a bit like techies recommending thinkpads or macbooks which gave those respective products massive boosts.

It reminds me of the study of WWII airplane, when trying to figure out where to reinforce the planes. The key was the absence of data was more important than the plethora of data.

Sharpshooters fallacy is the name of the cognitive bias. It happens in a lot of fields; notably, finance and investment.

Actually, the WWII example is Survivorship bias: https://en.wikipedia.org/wiki/Survivorship_bias#In_the_milit...

Both fallacies apply, as do many others. It is a mistake to believe only one fallacy applies in a given situation.

I shall call it... the singular fallacy fallacy.

Yikes, I can't see the forest for the trees!

More commonly known as survivorship bias.

"Context" is definitely a word of the decade nominee.

As a non-English computer user, I'm increasingly annoyed by Crowdin-style jumblations. Missed context is the common trope for both - whether the less-used feature do mean the feature is less important, or whether the "Play" on a button do mean "I instruct you _Play_ this media" or "I want to _Play_ this game" depends on the context(the language I mainly use do use separate words for the latter two).

There's a chapter in The Messy Middle (Scott Belsky) titled Data is only as good as its source, and it doesn't replace intuition.

Pretty much the problem in a nutshell.

you don't like your hazards hidden behind 3 submenus? you monster

Is it really hidden that deep?

By regulation (at least in Europe) that's a physical button, so is unchanged. But the point applies for fog lights for example. They used to be on the quick controls menu, which was already bad compared to physical buttons, and are now a further click away as if they're not something that you need to use while driving when suddenly entering a foggy area. The new UI is quite bad.

I find it hard to understand why these things are allowed to be more than one button away in the first place. You really don’t want people driving a 2 ton monster taking their eyes away from the road to locate something 3 submenus deep.

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