The Brown M&M's Principle | Hacker News Reader

The Brown M&M's Principle

effectiviology.com

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It's strange to see the rehabilitation of the famous Van Halen rider. Until it was finally discovered in 2011[0], the phrase "no brown M&M's" was interpreted as an example of crazy demands from entitled rock stars.

[0] http://web.archive.org/web/20200112124637/http://www.thesmok...

It's unclear to me what is the truth. David Lee Roth's quotes here do little to indicate it was a professional way to ensure rider compliance, given he trashes the green room, and does the show anyway destroying the arena floor. If a venue failed the M&M test then the band did what exactly?

His autobiography has more information, but they also did a full line check when the rider was not obeyed. I would imagine they were able to check everything but the floor's stats.

As to trashing the room, they were rockers in the 80's. He does mention he thought it was a funny story that he trashed the green room and did $85k in damage when it was mostly the floor damage. "Why let a good story go to waste?" was the quote.

https://www.youtube.com/watch?v=_IxqdAgNJck

Trashing the green room makes it something to write home about, so future hosts would be more careful about reading over the instructions

Maybe not in the van Halen example, but such behaviour bears the risk of forcing the supplier to optimize for the "brown M&M" and ignore the rest. Especially if you don't check for all the other stuff as well.

That's why you save the truth about the brown M&Ms for your autobiography.

That’s a useful addition. I was thinking it is kind of pointless to have this indicator that only tells you that something might be wrong when it is too late. The article does not address this aspect if I’m not mistaken.

There were different people involved.

The idea probably came from a brilliant tour manager, but like everything in the music business, the talent gets the credit.

I was active in guitar forums on the late 90s, early 2000s, and the brown M&M thing and its purpose was known then.

fun anecdote: when I first apprenticed for heavy diesel repair there was a safety practice at the shop that was weird but never ignored: Always return swivel jacks to storage with the jack pin in hole 4. no exceptions. even though the stand was unloaded and not used, it seemed weird to be so specific but the rumor was youd get fired on the spot if you didnt do it.

Eventually I asked an old timer whos name was on the training SOP. He smiled and told me, "people who cant be bothered to pay attention to the swivel jack pin when its safe, probably wont when its under load."

I do this in code occasionally. Leave in a mistake and see if the reviewer catches it. Now I know who pays attention and who rubber stamps my diffs. Sometimes you want one kind of review or the other.

You have to A/B test this though because who knows when somebody is in crunch and doesn't have time!

Also, from a teammate perspective, it might be worth pointing it out to the person. "I noticed a bug in the PR that I found later... want to show you why it could be a problem so we don't let it slip next time"

Imo I usually just fire the PR off and message on Slack saying, "this one needs to ship ASAP, anything truly bjork'd here?"

Or if it's going to be critical code, "The blast radius on this one is high. Give it a thorough scan please!"

Communication is key :)

> I noticed a bug in the PR that I found later... want to show you why it could be a problem so we don't let it slip next time

I don't know, that seems kind of confrontational. If I got called out for missing a bug in a review I'd be annoyed

That's true, and it definitely can be!

In my opinion, the best way to approach this situation is with "non-violent communication"[0] in mind.

Don't make the conversation about "this is your fault, do better", instead make it about "I noticed a bug in my code that could have broken production and I think we can do better".

It takes trust to pull off conversations like these without coming across as a prick. This type of empathy is particularly important when mentoring others because... People are always going to make mistakes. They create great opportunities to help somebody learn though.

When I am being taught something, I learn much more quickly when somebody points to somewhere I failed versus explaining an "abstract" bad pattern. Maybe having the "abstract" idea first helps. It might make the "failure" easier to stomach later. For me though, those moments of stumbling always stuck as lessons I reflect back on the most.

My attention to detail with code became a lot higher when I was on-call and prod broke at 4am because of a bug I let slip!

0: https://en.wikipedia.org/wiki/Nonviolent_Communication#Four_...

Not every reviewer has a "fine-toothed comb" philosophy.

Unless code is algorithmic in nature, I look at architecture and approach only.

A good post on the topic: https://blog.danlew.net/2021/02/23/stop-nitpicking-in-code-r...

Kind of a corollary: Place something fixable in your PhD thesis so the examiners can find something to write about. Something that doesn't make you look stupid but will make them feel like they'd done a thorough review and won't focus on your more subtle but perhaps more disastrous errors. Perhaps just a thing PhDs tell other PhDs to do but never actually do themselves.

Isn't this more of a corollary "remove the duck" principle [1]? The idea being, you expect the reviewer to force some change, so put in a trivial & obvious stylistic difference so their need to make changes are assuaged.

[1] https://news.ycombinator.com/item?id=9137736

I maintain a small fleet of vehicles. I keep a set of worn pads, rotors and tires that I put on every vehicle before it goes for state inspection. Steering/suspension parts replacement fell off a cliff once I started doing this. I would say this approach taught me something but it just confirmed things I already knew.

So needed to something to correct? So you made obvious small issues?

Used to do this on mock-ups of apps I was building. They wouldn’t fuss at the core functionality if they changed something obvious and not important.

>So needed to something to correct? So you made obvious small issues?

Exactly.

The tall nail gets the hammer. The shop that passes all the shitboxes gets the audit.

They don't want that audit and if that audit comes they want the paper trail to make them look like they're hard-asses about everything just like the auditor wants to see so they don't lose their license. The deal is that safety inspections are basically guaranteed work for the shops and exchange they get an incentive to not fudge emissions inspections. I dunno if that's still how they present it but that's what the 3rd party that runs the state training was telling everyone years back and the rules haven't changed since then (other than some more increased reporting requirements that are either to reduce odometer fraud or lay the groundwork for a mileage tax depending on who you ask).

Code reviews aren't there to catch mistakes. That's the job of unit and other tests.

Then what are they for?

Design considerations

Right.

So ignore mistakes in code reviews?

Unit tests are useful, invariant testing in code more useful, but code reviews and user testing are important too, for catching mistakes.

Apparently developers spring fully trained from Zeuses head in your company :).

This seems like a strange thing to do.

Laying down traps for your co-workers sounds strange to me as well, we must be working in different kinds work environments than the parent commenter.

I hate these tropes that exist somewhere in the "rules of thumb and vague proverbial advice that can be twisted to mean anything" space.

Known metrics become targets. Unknown metrics destroy morale. At the end of the day there is no stupid proof easy rule of thumb shortcut that replaces the need for people to do their jobs properly.

Its not really a metric. Its a spot check of the known metric. Not much different then pulling some random invoices and deciding if you need to do a full audit.

I agree. Defense-in-depth in terms of risk management. Use many strategies, in depth and breadth, holistically to manage vendors. There is no single magic action to make vendors do good work and be competent. It's lots of annoying managerial effort, but hopefully it's prevention and effort applied effectively. I think just showing up, having a look around, treating vendors as human, and being curious without annoying curious about what's going on goes a ways to show there's humans and not just nameless a corporation behind a project.

Trust but verify / you don't get what you expect but what you inspect. Random but easy to inspect riders in a contract helps signal if the other parties read the contract in its entirety rather than just set it aside. The basis for it was avoiding injuries from inattentive, incompetent, and/or negligent electricians and riggers in particular. It's merely one technique among many in a holistic strategy of risk management. It's not a Silver Bullet panacea and it doesn't work everywhere.

I've found "brown M&M" tests are good for telling me how much I need to investigate things. For example, let's say your job includes verifying data submitted by hundreds of hospitals. You don't have the time to do deep investigations for all of them, so you use a script to look for red flags (e.g., discharge date preceding admission date). If there are no red flags, you still quickly look over a small sample. If there are red flags, now you're going to spend a lot of time looking for any errors and their causes.

And it's not just to save time. You're only human, so trying to be thorough with every submission will likely result in you getting sloppy because all those reviews of good submissions gives you a false sense of security.

This principle is used in traditional auditing as well.

Periodically pull up some randomly selected documents and ensure that they match the corresponding records. If you can’t find the documents or if they don’t match the records, you trigger an audit.

At one of my employers, we did this with backups. Every now and then one of the team was asked to claim to have accidentally removed some files, asking the sysadmins to recover them. This was a regular sanity check that to confirm that incremental backups were working.

I was an engineer working on a storage system for backups. We encouraged our users to do restore tests, like randomly select a mailbox and restore it from backup into a test environment.

The aphorism we used was “nobody needs a backup system, but everybody needs a restore system.”

We have self-service backup restores for user files, so we get to spot check which users can be bothered to read the documentation on the wiki...

Yeah, when I was an operator back in the 80s (9-track tape, FTW!) this was the policy. Every so often someone would request a file from last month/6 months ago/3 years ago, just to see if we could retrieve it.

Also in psychological evaluations. A questionnaire may include items that people pretending to have some condition think they should answer a certain way, but would be untrue in (most) actual incidences of that condition.

This would be easily foiled by reading the wikipedia page of the condition beforehand, right?

Such advanced cheating would require enough intelligence, mindfulness and self control, if not psychology competence, that it can be considered a proxy indicator that the subject is more or less OK.

The real Catch-22.

The problem would then be catching those cheaters.

What are some examples?

Depends on the domain but in general it relies on item responses that people in general tend to think are typical of some "condition" (in a broad sense of the term) but actually are not. This requires a lot of data collection usually.

So, for example, items that people tend to think would be incorrectly responded to by people with dementia, but are actually easy for people with dementia to respond to. Or items that sound like they'd be endorsed by people with severe mental illness but are not.

In more sophisticated implementations, it's not just responses to these types of items, but multivariate patterns of responses that are unusual that are flagged. So, for example, not getting items increasingly incorrect with increasing difficulty (i.e., getting easy items incorrect and hard items correct) might be flagged, just for one example.

Specific examples are hard to list because (a) it would violate test copyright and/or other ethical issues, and (b) are sort of idiosyncratic and require actual data on the items.

With cognitive testing for example, lots of times certain types of memory are intact in severe brain injury but people who are faking don't realize it.

Actually this is kind of telling with regard to the "brown M&M principle."

The the items in an effort/response validity measure reflect some kind of systematic schema on the part of respondents. It's very non-arbitrary.

The brown M&Ms in contrast are sort of trivial and arbitrary. That is, there's nothing about M&Ms that has anything to do with actual stage safety or management, and the assumption that attention to M&Ms and stage safety are the same is kind of odd.

In fact, one might argue that the brown M&M clause pulls for a sort of cargo cult phenomenon, where people are following something to the letter without regard to deeper principles or understanding of what's important or not.

Sometimes psychological tests do have items that test for random responding, which is maybe more comparable. But even then I don't think it's the same, because it's still item responses that are critical. To me the brown M&M test is like looking at the response time to an initial consent page, and arguing that if that is unusually long the person probably isn't responding to the items per se.

I think there's maybe something to the brown M&M test but to me it pulls for the wrong things. Why not just actually, you know, make sure they abide by the long list of supposedly safety-critical items that you specified? If you as the performer are so sure that they're safety critical, but can't be bothered to check those, and instead rely on brown M&Ms, because it's easy to check in your dressing room, who's the one being lax about the stage?

> The brown M&M’s principle is the idea that small details can sometimes serve as useful indicators of big issues.

> This principle is named after a rock band (Van Halen), who had a “brown M&M’s clause” in their contracts with event organizers, stipulating that the organizers must provide M&M’s in the backstage area, but that there must be no brown M&M’s available. This small clause gave the band an easy way to check whether organizers actually paid attention to all the details in the contract, which was important given how complicated and potentially dangerous the band’s production was.

Ok, but it also means that somebody touched all your M&Ms.

Those are not for eating. For visual confirmation only.

It's possible to be in a room with M&Ms in a bowl and not eat them? TIL.

If you see the usual percentage of brown M&Ms in the bowl, you can eat them while you wait for a full re-check of every power and weight item in a very long checklist, confident that somebody poured a bag into a bowl and left them unmolested except, maybe they ate a green one.

If the M&Ms are devoid of brown ones, you don't eat them because you know some peon was told to go through the bowl and take them out, and that sort of person will eat the brown ones and then go back in with their bare fingers for the next one, and thoroughly stir their fingers into the bowl looking for the last brown ones.

Now, if the M&Ms are carefully laid out in a series of monochromatic bowls, with no brown bowl in sight, it's probably safe to eat them because what sort of maniac would do that sorting without aid of a knife or spatula or something, right? But you shouldn't eat them because that's a work of art.

Or just don't be a germophobe and eat them regardless.

If they don't have peanuts in them, why would you eat them; yuck.

To be frank, I don't think sanitation and cleanliness were top bill for the Van Halen members back then.

> Ok, but it also means that somebody touched all your M&Ms.

Did latex gloves not exist in the 80s?

Actually, come to think of it, it's possible one could simply order pre-sorted M&Ms directly from the factory if one were buying in enough bulk.

You can now, not sure if that was available at the time (in the volume sensible for a green room): https://www.mms.com/en-us/shop/single-color

Amusingly the UK version does not offer brown ones.

> Did latex gloves not exist in the 80s?

Yes. As did plain old (but effective) soap and water!

> Ok, but it also means that somebody touched all your M&Ms.

Someone touched all the toppings on the sandwiches as well, catering knows how to avoid poisoning the talent and crew.

Having worked with riders, there are a lot of things that folks ask for but which get clarified by communication.

When a request is super specific, weird, and hard to fill, it usually gets pushed back on, at least in my world.

My understanding of the "check" is that you get a call from the person advancing the show to ask about the strange demand, not that you verify compliance.

> Ok, but it also means that somebody touched all your M&Ms.

This would be normal for M&Ms that were just dumped into a bowl, too -- you can't eat from the bowl without touching the other M&Ms.

If curious, past threads:

Brown M&Ms, or Why No One Reads the Manual - https://news.ycombinator.com/item?id=23985817 - July 2020 (150 comments)

The Truth About Van Halen and Those Brown M&Ms (2012) - https://news.ycombinator.com/item?id=18643258 - Dec 2018 (15 comments)

Why Van Halen's tour contract had a "no brown M&M's" clause - https://news.ycombinator.com/item?id=7754334 - May 2014 (158 comments)

Why Van Halen had brown M&Ms contractually removed - https://news.ycombinator.com/item?id=2839581 - Aug 2011 (55 comments)

Why Van Halen's contract calls for the removal of all brown M&Ms - https://news.ycombinator.com/item?id=743860 - Aug 2009 (79 comments)

A common example of this is surveys that have a question that reads “Select strongly disagree for this question” to weed out people randomly choosing answers.

That seems like it will also weed out people who decide to have some personal fun with the stupid question while answering the others accurately.

Is "to avoid websites that have an outdated design, by treating the design as an indicator of unreliable content." a good example for the M&M principle? Seems more like an example for superficiality, where appearance counts more than content. Many people have been deceived this way.

I'm hiring for several positions right now (non-engineering). At the end of every job ad is a section titled *HOW TO APPLY*, in bold and with asterisks like that, with the simple instruction that the interested candidate needs to go to a linked Google Form to fill out some details. For us, this centralises all applications into one box that we can review, and also tests to see whether people actually read the job description.

Around 10% of applicants actually fill out the form. It's not a tough form at all, but it's striking that so many platforms have made it easy to one-click-apply, that shotgunning job applications is very common now.

So yes, fully agree that carefully reading a document is a key pre-requisite for a knowledge worker job.

To be fair, most online application processes are fairly broken. I'm sure everyone here knows what it's like to painstakingly enter your complete personal information and work history several times, when everything is clearly on the resume you've already uploaded. Or to have it entirely erased and need to enter it a fourth time because you accidentally went back to a previous page, etc.

Often, if a job has a form that smells like this, I'll bypass for other options, as to me it indicates bureaucracy and institutional stupidity, which I don't want to deal with on the job. It's my brown M&Ms clause.

Yes, but you wouldn't click the "Apply" button on the actual job post (ie, LinkedIn or whatever) and NOT follow the instructions would you? The point was that if you're going to apply, follow the instructions in the job ad.

When I worked for a government agency, this system ensured no personal details made it through to the people assessing candidates. Name, age, sex, nationality etc were all removed.

Sometimes other information gave the details away anyway. ("Westminster School for Boys, 1969")

I get where you are coming from. It is not a bad indicator. I as job seeker would have probably just skipped the job all together. Having been through this system recently, one more form to fill out that is hand crafted, would have made me nope out. You explain why but it does give off an interesting look you may want to rethink. Now you may be fine with that. But my level of dealing with HR form systems has dropped to a dramatic level of low, please end me, levels. A hand crafted one would make me think 'that is odd'. The whole fill out this form system almost every company has now, plus other tests has worn me out. It does not even matter how 'easy' the form is. It is just one more hoop to jump through.

I also understand where you are coming from. You have 1 position and 100 resumes. At least 99 of those have to go. Filtering for not reading the instructions is not a bad one. Just be careful you can end up with a set of people who do not know how to do things that are not in the instructions, and will block out until someone corrects the issue.

> Around 10% of applicants actually fill out the form.

That is a very good sign that it is you who is doing something wrong, not the applicants.

The ends of my ads usually include: please send your resume in HTML, PDF or plain text, and a short discussion of a time you solved a technical problem.

Most people managed the first part.

I remember seeing something like this on a test in grade school; if I recall correctly, there were instructions at the top under the "name" field to not write your name there, but write it on the back instead. Following those instructions would comprise some small portion of the total grade.

In hindsight, I'm not sure what the point was of checking who was reading the instructions closely on a test...

Pretty good way of introducing the idea that the system can be capricious and cruel for no discernable benefit.

A lot of things in our society just wouldn't work without somebody paying attention to details. I'm not saying that's a good way to teach it, but it needs to be taught. Even among artists, the greatest are those who show not just inspiration but also meticulous craftsmanship.

This guy's trying to get people to read a 53-page contract and here I am I'm just trying to get people to read a two sentence email

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