[wzwy]

> (d) Compute the mean age, and print it out as the median. It's much easier to program, and Mary Jones will probably never notice the difference.

Lol. If it’s not the most important statistic to Mary Jones, I can see why a programmer might do this.

> Mary Jones in the Accounting Department tells you that she has a file of personnel records [2022 update: an Excel sheet] and asks you to develop a program to compute the median age of the personnel in the file.

I’ll probably add option (e) if it’s Excel: Mary Jones, you can learn and do this yourself. Just Google it or something.

[bambax]

It's not just Mary Jones. The controversial (to say the least) French medical professor Didier Raoult last year showed he didn't quite grasp the difference between median and mean. There was some mockery on Twitter but no journalist ever called him up on it.

[brutusborn]

I couldn't believe an Academic could be this ignorant, so I had to look it up. I found it but only basic french. I can't find a translation, does anyone know of one? https://mobile.twitter.com/cubic_logic/status/15410902478613...

[d1sxeyes]

EN: '[...] some things to put together. You see that if we look at the mean or the median, the mean is when a distribution is like this [indicates a bell curve with his hands], we can calculate a mean, but when it's like this [wiggles his finger], you can't calculate a mean, you do the, the, the bar which separates them in half. And so [...]'

FR: '[...] d'objets de mettre ensemble. Vous voyez que si on regarde la moyenne ou la médiane, la moyenne c'est quand une distribution est comme ça, on peut faire une moyenne, quand elle est comme ça on n'a pas [...] pour faire une moyenne, on fait, le, le, le, la barre qui sépare à moitié les uns les autres. Et donc [...]'

There's a short phrase I can't quite catch at about 9s... which literally translates as 'we don't have [...] to do a mean', so I'm inferring that he means 'you can't calculate a mean' from context (previous clause 'on peut faire une moyenne' => 'we can do a mean' => 'we can calculate a mean').

[alain94040]

Actually, I believe he is probably correct in that case. He is discussing whether the mean is meaningful depending on the shape of the distribution. It's probably not fair to summarize his explanation as saying he doesn't understand mean and average.

HN's guidelines recommend to assume the best.

[d1sxeyes]

I would agree that you should always try to assume the best (and I didn't actually suggest he doesn't understand), but he certainly explains it clumsily, and his explanation does not illustrate the difference between a median and a mean, or when one would be more meaningful than the other.

[pkd]

I don't think it's the best explanation, but I do think he understands that mean as a measure of central tendency is not that useful when distributions are skewed or multimodal (the squiggly line gesture).

[deanmen]

Excel has MEDIAN built-in https://support.microsoft.com/en-us/office/median-function-d...

[sbierwagen]

You can also install the Analysis ToolPak add-in, select the column, click Data -> Data Analysis -> Descriptive Statistics. Gives mean, median, mode, SD and a bunch of other things. https://support.microsoft.com/en-us/office/use-the-analysis-...

Has been in Excel since 2007.

[mananaysiempre]

Since 1997 at least (except it’s under Tools there).

[cwillu]

The problem states that Mary has an Excel file. It does _not_ state that Mary has an Excel software licence, or even a computer with which to run it.

[k_sze]

You have LibreOffice nowadays.

[ZoomZoomZoom]

The problem states that Mary has an Excel file. It does _not_ state that Mary has an access to a personal computer or a device allowing remotely accessing one.

[k_sze]

My bad. The problem also does not state that Mary has adequate eyesight to use a computer or that she even has access to electricity to power a computer. Life is so hard

[pjc50]

Quite difficult now to reach this scale with personnel records, but: imagine that you're asked to provide the median of one trillion data points. This could provide lots of interesting possible approaches, since it's about the boundary between "big data" vs "do it on your laptop". And you can't just load it into Excel.

(and also to ask about the range of the data!)

[nmstoker]

For a trillion records, if you were in the UK government, you might just drop those above the Excel limit and proceed until journalists flagged the concern nationally.

Background context here:

- https://www.theguardian.com/politics/2020/oct/05/how-excel-m...

[raverbashing]

For 1 trillion records I'd say: estimate the probability distribution and values and give the corresponding value as the answer

[Psyladine]

re: (e), they can't. I don't mean they cannot physically operate the sequence of events (even a properly incentivized chimpanzee could do that), but that they lack the programmatic sense of problem solving that is assumed (quite arrogantly) by the programmatic crowd.

In the same way people take their cars to mechanics when they can do the job themselves, or call triple A for a flat tire when the spare and jack are in the trunk, or reach for the phone instead of a plunger when the toilet backs up, people don't lack the specific skillset, they lack the openness to problems being solvable. They are in perpetual search of answers, not solutions.

They don't want to learn to fish, they don't want to expend energy on process. They want someone else to do it. It's not laziness, it's not incompetence, and it's not entitlement. They are just of a mindset they cannot solve problems, and so they pick up the phone and abstract away the answer.

And I promise you, no 10 minute condescending conversation with someone is going to redefine their core attitudes about life. You're just going to have your well poisoned in the break room with your piss poor attitude because she called the plumber and he told her to fix her own shit (in a manner of speaking).

[Ma8ee]

No, it’s not that they don’t think they can do it, it’s that one of the foundations of modern economics is specialisation. I know I can repair my car myself, and even think it would be kind of fun. But the mechanic in his shop already knows exactly what to do and in which order. I’d spent hours reading and watching videos before I even could start and still make plenty mistakes. The mechanic already has the tools and know where to source the parts. I’d spend half a day just to make sure that I’d get the right parts to a reasonable price. In the end it would take me four days what the mechanic would do in an hour or two.

And I buy my fish in the supermarket, for even more obvious reasons. This example make me believe you actually might be trolling.

So the lady in the original examples uses that the company already employs people who are specialists in doing this kind of things, Because she has more important things to do with her time. And that you don’t understand what she’s doing all day that make her not having time for fighting with spreadsheets is your failure, not hers.