gentle ways to tell someone it's a bad idea

Casie Becker wrote:Maybe not on topic, but I really want to share how much delight this thread has given me. I've laughed at loud several times at the shear joy I get from how positive the mindset of this forum actually is.

When given a improbable scenario to practice gentle dissuasion, the immediate response is to find ways to make the improbable work. I apparently missed a thread cleaning, but I haven't seen one person who even for a theoretical exercise managed to actually be discouraging.

I even love that the last post above mine has decided to one up the improbable with a bigger challenge, and some theories to start making it work.

Well, Cassie, I wasn't really trying to make the cardboard fire place work as much as I was trying to demonstrate the process of evaluating the attributes of the material, and the conditions under which it would have to function.  It was kind of an exercise in reducing to the absolute ridiculous.  

I enjoy the positive mindset here on Permies as well and am thankful to know that I've contributed some amusement, enjoyment to your day.  

Thekla McDaniels wrote:

I've enjoyed thinking about when, how, where it might be just what I need.  It is a mental exercise, to look at exactly what the material is, and what it will and won't do.

Looking back at what I wrote, and thinking further, this business of looking closely at the properties of a material, and the function I'd like it to perform seems an integral part of permaculture practices.

I think many observers see permaculture as people doing weird things that no one else does, is not conventional, utilizes materials (sometimes even "junk"! OMG) in weird ways.  I think the novel use of materials comes out of the process of a person looking at what s/he wants to accomplish, and what's available in terms of time, materials, work force and financial resources, and making then utilizing those resources as best they can, according to the current conditions and to accomplish what is their current highest priority.

Encouraging people in this process might be the very heart of teaching permaculture.

I think I posted about using cardboard in the roof of my chicken coop....
I think I am good about not being unkind in general, but I have had my posts deleted, and I am glad they were.

Some cardboard is coated with waxes, making them water resistant and  unrecycleble.
They are often compressed into bales.
For I long time, I thought of them as potential building blocks.
When I goggled looking for examples I found one site dedicated to the idea.

Perhaps an example where the poster advocates for the use of Roundup would be more challenging. Something that goes against the basic values of the site.

For example,the lead pagen at my Unitarian church recently gave a presentation on global warming that presented it as real,human caused, and at this point unavoidable. As in, go ahead, try to stem the tide, but you will fail.

People were shocked and outraged,even when he added that the ecosystem would survive and recover,just not society.
As die hard liberal types, my church mates are wedded to the idea that they can change the world.
Telling them"The planet is fine,the people are ducked" ,did not sit well with
them.

William Bronson wrote:

Perhaps an example where the poster advocates for the use of Roundup would be more challenging. Something that goes against the basic values of the site.

That would be in violation of permies publishing standards and would be deleted.  

paul wheaton wrote:

If people want to talk about GMO's, herbicides, politics, religion they really need to find someplace else.  

https://permies.com/t/17422/tnk/permies-publishing-standards

Good point. Maybe something more borderline? Metal rocket stoves come up a lot,wood building supports in contact with soil,clearly I don't know,but responding to one of the verboten topics would be an exercise in restraint.

I deliberately chose a topic that isn't common on this site (or any that I know of).  This way we can play with the idea of a cardboard roof without opening up old wounds that might be associated with something like metal core inside a rocket stove.

Let's stick to the topic at hand (how to communicate disagreement in a positive way) rather than rehash old battles.



Now, if you wanted to practice gentle disagreement with our fictional person Lovescardboard, who for example is thinking of building a cardboard burn chamber in a rocket stove, that kind of thing would be fine.

OK, cardboard themed...would a 'cardboardlover' (who wants to use it for a roof) think this video helpful?  I don't know, as it's on the edges...cardboard as a material used for creative things....if it were me asking, I think I would like ideas from all angles, especially ones I haven't thought about...others, I know would not, and there's usually no way to predict.  

I just remembered that I'm supposed to be 'gently disagreeing', but I was already convinced by you all that it's not a bad idea

I think there might be some inventive ways in the videos in this thread about other ways to recycle cardboard

this video in particular..."Trashformation: furniture & shelter from recycled cardboard" might provide a lead to something that would apply to a cardboard roof...might be worth investigating more of their projects.....

I realize that my last post wasn't following the 'gentle ways to tell someone it's a bad idea' theme here.  I don't think I can do that even gently as usually the question is asked in earnest and in the end, as we've seen in this thread, with enough group thought, many things seem more possible.  

Other than posts that might be 'baiting' us, or obvious ones that aren't playing by the rules, I think most folks have found a safe place to play here and might feel freer to express some of their wilder thoughts out loud.

I think exploring an idea as though it were possible is many times more helpful than trying to dissuade someone because we 'know' it won't work.

I sometimes try to dissuade people from installing a bunch of techniques and structures without any kind of permaculture design, because having done that myself, I have a haphazard mess that doesn't work very well.  I'm not sure if this falls into the category of "telling someone it's a bad idea."  For some people, installing a bunch of techniques and things without a design might work great (but is it permaculture?), or, it could be that their method of designing is to install a bunch of things and then work out the design "backwards" (which I'm finding really difficult).  I sometimes feel like I might be running around waving my arms screaming "turn back before it's too late!"  I don't know if it has been effective at all.

I am enjoying catching up on what seems like MONTHS of posts, and when reading this thread, I am immediately reminded of why I like Permies so much. This was a very intelligent and fun question to pose-and thinking exercise. Strangely, (and unrelated) I was responding this afternoon to a "purple moosage" from a cool person who inquired on where I live in New Mexico (pros/cons) etc, and asked for thoughts. I believe that she saw my post in a "Southwest" forum, where a group of kindhearted souls, had exchanged basic info/stories/locations in New Mexico. Since she was asking my opinion of things, I said to her, that some of the locations listed that I saw, I felt were not ideal, or really put someone up against a lot of disadvantages-yet I knew that land, in some of these areas, were very affordable-but there isn't any water. I said in my message, that many are successful with rain catchments, and various other strategies, but since the majority of the folks in the thread seemed rather "new" to permaculture, this seemed, despite the affordable land, to be a death sentence-at least for me, However, I wasn't going to say something like that in a forum, as everyone has different socio-economic (and pretty much every other variable you can imagine) capabilities (and often these can fluctuate wildly in our lives) and I would never want to be a "negative nellie" to anyone's dream- especially if they made the step to buy land and do it. Not only do I think that is a poop-y  way to be in general-(heh, okay so I devolved to kindergarten vernacular for a minute) but as a newer, yet 'serious' person trying to put Permaculture into action in every aspect of my life, ( and often massively failing at various goals, sometimes day after day, (and then maybe a little break through) Doing this, or making such a change-is hard enough, then to have someone point out to you, what you probably already know. (regardless of what that is. Cardboard roof, Your 5 acres for 500.00 in the middle of nowhere with no water or towns in sight) So I guess, I said "But this is just my thought, if you can afford to buy somewhere with a well, or access at least 30 mins away to a small town, do that, don't be seduced by the cheap land) but I felt that in that context, since I had asked some questions, and I knew more of the situation with the person, I would not offend them with that opinion. However, often in a thread, there are a lot of different people communicating, and it is true, Permies.com is such a huge resource, and home to a vast plethora of folks at all different levels of commitment, skill(s), belief systems, or ways of practice, that sometimes, you may inadvertently offend or hurt someone without even meaning to. I would like to think that 99 percent of the fine folks on this site, try their best to be sensitive to others (generally) and don't want to be mean, (or come across as too bossy pants (here we go again with my inner kindergartener! ha) - It's so weird that I stumbled upon this thread, as part of the dialogue that was going on, was that, in this person's real life, the country they live in, they find people "negative" and they were looking for community. I stated that I too, in the "real world" have had some not so awesome experiences, and longed for the encouraging utopia that is Permies.com in my day to day- but I stated that I was well aware, and appreciative, and somewhat, (since it seems to work very well) of the "tight ship" that is run by Paul & Co. and that I think the good vibes here are a direct result of weeding out some of the poop-y ones. In all honesty, just like this thread about cardboard and trying to gently tell someone that something might not be the "best" idea- It taught me a lesson I wasn't expecting, in that as a society, not just Permies.com, we can step off our soap boxes, and instead, turn the attention around, and open our eyes and ears to others.

I have learned ALOT from advice on these forums. I seem to be the queen of "this seems like a really good idea!" only to fall flat on my face. I also agree that each blunder, can really be a learning exercise. I think, like others have also stated eloquently in this thread, it is how you present your advice/thoughts. I find it refreshing that Permies somehow manages (and I'm sure with much effort and with the moderation) to control some of the less inclusive aspects and dogma that can come with being into Permaculture. I have been turned off by many cool concepts or ideas-simply by the attachments and banners that others slavishly fly (or try to impose upon others) as "part" of being into....whathave you. I really like that for the most part, (unless I am missing some major thread trimming) the vast majority of folks on here, get "the rules" and despite their differing backgrounds or belief systems, we all play nicely together, and even better, seem to help each other. I wish life was more like Permies.com.


Now onto this question. You know, I have been in the midst of a volunteer/apprenticeship building an adobe house using ancient methods (hands, traditional stone dug foundation, basically how things were done Indigenously millennia ago) so my first thought was "Cover the cardboard with mud, seal it off"- But I am at the point where i am having dreams about plastering adobe, and I realize my brain is turning to mud. (ha ha! but what a great learning experience)

I agree with others who said, I think the best thing would be to find out a little more info on why the person wanted to use cardboard, a little more about them (their circumstances, level of experience/expertise, financial capabilities) and this info will allow you to be more sensitive and even if you still want to tell them "cardboard is not a good idea"-you can consider their situation and THE PERSON they are. (the positive, TRYING to make changes/live sustainable, embrace what everyone here feels are "good things") and be a comforting voice-not lumped in with the group of people who probably already told them that permaculture wasn't "possible" or "feasible" or that they "were being too idealistic or irrational"-as I know from personal experience, when you're making a big leap (or even a small one) those comments hurt, even if they don't "hurt", they can make you doubt yourself, and the last thing I think anyone on this forum should be doing is making someone doubt at least trying.

So I guess what I was going for in this rant-a-roni, is get to know the person, even if it is just a name on the screen. Before you clear your throat and turn into mr. mrs sage advice, remember to be kind.

A picture that keeps popping into my mind is of homeless people living in cardboard boxes.     They likely aren't very comfortable, but they would keep the worst of the rain or snow from drenching the person(s).

I love the idea of earth plastering the cardboard!    

Karen Donnachaidh wrote:
A flying machine? What are those crazy Wright brothers thinking?

They were thinking of what they knew about physics, which many of their detractors likely did not understand. This has been a useful thread to me, because I do tend to get into the mindset of refuting. I suppose it may come from my experience in academia, where debates can get lively to say the least. It doesn't help that there are some issues in which I am emotionally invested; obeying a "be nice" rule would first require me to step back from my emotions.

The easiest way is to deflect the answer away from them and their bad idea (i.e. avoid statements like "If you do that" or "that idea won't work")

Instead of addressing them directly, frame it in the context of yourself or someone you know. For example "Well if I were building a roof I would probably think about using metal or roofing shingles so it would hold up to years of rain" or "I think lot of folks end up going with shingles or metal to prevent water damage".

If they didn't get the hint and still plan to build a roof out of cardboard then I would ask them to post updates and pics on its weather resistance.

raven ranson wrote:The problem is, how do we tell them what a bad idea it is while still following the Publishing Standards of this site?

How about:

"Try it and find out for yourself if your idea works."

I'm constantly coming up with all sorts of crazy ideas so I try them out myself just to see what happens.

That's what life is all about... finding out.

I like the idea about answering the question with a question... in the "cardboard roof " example, everyone jumped to "it'll get wet", "it'll rot", "it will never last"... But what if that wasn't the point?
Maybe it doesn't get wet (a sunshade) or doesn't need to last (a shelter for a transient, who will make another at a new place/ a dog house so your allergic aunt can stay the night/ or her dog can stay the night and not kill your cats)

"Tell me more about this cardboard roof, what does it do?" might be a place to start.
"What about this cardboard roof idea is most attractive to you?" (free, light weight?, you live beside an appliance store with an alley FULL of boxes...)

Sharing real experience of a failure to illustrate just how bad this idea is has more standing than just saying it is dumb (which is easily interpreted as unfounded opinion)

This is a great thread!

My question would be why does one feel they have to tell someone they have a bad idea? why not just add a few other suggestions or examples of how you have done things. At the end of the day if what they are doing is on their land and not adversely effecting others why bother. Even if it is a bad idea them working through it might lead to other things that work.

Say building with cardboard maybe they find out it is not great for long term but for a fast short term animal shelter it would be cheap and bio degradable option.

I see far too many examples of people thinking things "should" be done their way or no way in my reading of this forum. I believe it could lead to people deciding they don't want to be part of a community that judges them verus provides useful information.

I think it is also worth pointing out that on some forums a large percentage of the posters are Aspies (aka individuals with Aspergers).

While that number is far lower on gardening/homesteading sites there are still a few floating around. Those folks often have a VERY hard time on forums like this because they do make blunt comments and their social skills suck.  I have known individuals on homesteading type sites that likely have Aspergers and they try to fit in to talk about their interests yet are often picked on and ridiculed or even targeted for harassment by mods because they inadvertently upset one or two "favorite" posters.

Lucrecia Anderson wrote:I think it is also worth pointing out that on some forums a large percentage of the posters are Aspies (aka individuals with Aspergers).

While that number is far lower on gardening/homesteading sites there are still a few floating around. Those folks often have a VERY hard time on forums like this because they do make blunt comments and their social skills suck.  I have known individuals on homesteading type sites that likely have Aspergers and they try to fit in to talk about their interests yet are often picked on and ridiculed or even targeted for harassment by mods because they inadvertently upset one or two "favorite" posters.

There are a lot of aspies on permies.  Including quite a few of the moderators!

Ron Rice wrote:My question would be why does one feel they have to tell someone they have a bad idea? why not just add a few other suggestions or examples of how you have done things. At the end of the day if what they are doing is on their land and not adversely effecting others why bother. Even if it is a bad idea them working through it might lead to other things that work.

Say building with cardboard maybe they find out it is not great for long term but for a fast short term animal shelter it would be cheap and bio degradable option.

I see far too many examples of people thinking things "should" be done their way or no way in my reading of this forum. I believe it could lead to people deciding they don't want to be part of a community that judges them verus provides useful information.

Sometimes, the "bad idea" could rise above disappointment... (in this example of cardboard as an appropriate construction material) and become dangerous, like maybe a "self-entombing underground cardboard house".

Allowing someone to believe that something like this is a "good" idea, might even border on criminal. Even if they only hurt themselves, on their own land.

There's a lot of issues surrounding safety that laypersons may be completely unaware of (trench safety, carbon monoxide, electricity, tractors/PTO, food safety, etc...)

And, a gentle "um, gee, maybe you shouldn't..." doesn't cut it if safety is on the line.

If you DO know better, you ought to speak up and educate.

Ron Rice wrote:
...I see far too many examples of people thinking things "should" be done their way or no way in my reading of this forum. I believe it could lead to people deciding they don't want to be part of a community that judges them verus provides useful information.

Ron, next time you see someone "shoulding" please use the report button to notify the moderators. We don't like "shoulding".

https://permies.com/t/36936

Any further discussion about moderation is a better fit in tinkering with this site: https://permies.com/f/11/tnk

I prefer not to say anything unless it is something I have direct experience with myself, and then I try to say what I did, how I did it, and if it worked for me.  I think that removes any judgement from my reply, and just tells what my experience was.  Unless someone is going to do something that is truly life-threatening, like cutting up an old gas can with a cutting torch, I'd rather wait and see how it turns out for them.  Maybe they came up with a great idea and my own prejudices blinded me to it.

And so what if someone tries something that fails? Many times failure is necessary for success.
Discovering for yourself why something doesn't work can be valuable knowledge.

"Edison made 1,000 unsuccessful attempts at inventing the light bulb.
When a reporter asked, "How did it feel to fail 1,000 times?"
Edison replied, "I didn't fail 1,000 times.
The light bulb was an invention with 1,000 steps.""

This is a hard thing for me, because I grew up farming.

For instance chainsaws, I have been logging since I was 15 years old, almost 30 years now. When people ask about safety chain, or a chainsaw to buy, I have some powerful opinions on that stuff...based on my experience...but I must step back and think that these people do not have 30 years of experience either.

Sometimes I reply, but lately I have been finding myself staying mum because I am not sure if I should speak up or not. Should I? I got 30 years operating a chainsaw so I got some pointers for sure, but then again it is not in the same capacity as me either.

Travis Johnson wrote:
Sometimes I reply, but lately I have been finding myself staying mum because I am not sure if I should speak up or not. Should I? I got 30 years operating a chainsaw so I got some pointers for sure, but then again it is not in the same capacity as me either.

Speaking only for myself, I think you should absolutely speak up.  If you don't, how is anyone going to learn from your experience?  Look at it another way.  Suppose you were interested in learning to paint, or sculpt.  Do you think there is anything you could learn from a master painter?  What about a master stone mason?  If I want to build a stone wall, and I voice that, should the master stone mason keep quiet because I don't have his talent and ability?  Or should he give me the benefit of his expertise, even if I can't re-create it?

Casie Becker wrote:Maybe not on topic, but I really want to share how much delight this thread has given me. I've laughed at loud several times at the shear joy I get from how positive the mindset of this forum actually is.

I feel exactly the same!  I really love the positive mindset of Permies!

I got another reminder of how much I love Permies.. from visiting another favorite forum of mine.

There was a post describing problem X
I replied, acknowledging that X is a problem and that I'd like to see something done about it. I then wrote a bit about my own experiences and what possible solutions/ alternative ways of thinking I've come up with, that make X not such a big problem. I ended by saying again how I don't mean something shouldn't be done about problem X.

I got ten replies basically saying I'm wrong. Most of the replies had 2 or more links to research that proves I'm wrong. Someone straight out said my experiences were irrelevant because I'm just one person. So, altogether twenty research papers/ news articles to prove I'm wrong, in one day.

The research papers and news links did contain some interesting info. I am glad that people were interested in discussing problem X.

What makes me really happy though, is that Permies exists The next time I discuss problem X I think I'd rather do it here

raven ranson wrote:People come to permies to learn new things.  There are all sorts of different kinds of people from all walks of life, all passionate about this world we live in and curious about ways to make it a better place.

Sometimes people come here with questions or ideas that seem like, well, like a really bad idea.  The problem is, how do we tell them what a bad idea it is while still following the Publishing Standards of this site?

Here are some guidelines I've made for myself.  

I think the first step is to take a moment to remember that this is a a safe place for gentle souls to talk about homesteading and permaculture.  There are going to be some ideas that I find unusual.  

The next step is to ask "why do I think that is such a terrible idea?"  Perhaps they are simply at a different stage in their life.  The Wheaton eco scale is a good example.  If I tell them what a bad idea I think it is, will it slow down their journey towards a more sustainable lifestyle?  Maybe they don't need to be told it's a bad idea.  Maybe it would be more helpful to suggest other ideas without pointing to the bad one.  Maybe it won't.  Sometimes the thing is to ignore the topic and move on.

Sometimes I just can't ignore it.  What then?

Well, there are lots of different ways to say something is a bad idea.

For example, maybe a person wants advice on how to get rid of their dandelions.

One reply could be: "only a stupid person would want to murder such wonderful plants.  don't you understand what great help they are in the yard?"  - If you ever see a response like this on permies, please report it.  There are so many things wrong with it.

First, it's a direct attack on the individual (calling them stupid, "don't you understand").
Second, it fails to answer the question.
Third, it is not solution focused.

From the point of view of the answer, this dandelion murder needs to know what a bad idea it is and how awesome these plants are.

From the point of view of Frustrated-with-dandelions, this kind of answer is hurtful.  It's provocative.  It makes them feel unvalued, not just because of the attack but because of the way their question was ignored.  This one answer can easily create an emotional block which causes Frustrated-with-dandelions to dislike dandelions even more and be less open to eco-friendly solutions like eating weeds in the future.  

This kind of response fails to help in any way.  


A more helpful reply could look like this: When I was a kid, I use this claw-like tool to pull up dandelions.  I only had to do it once a year and after two or three years there weren't anymore.  It worked really well.  Nowadays, I use the same tool, but not to get rid of the dandelions.... maybe some examples of all the great things dandelions could be in the kitchen... Of course, I like to leave some next to my garden so that it encourages pollinators to visit.  


This answer directly addresses the question in a helpful way.  It may not be the answer Frustrated-with-dandelions was looking for, but it is a solution that Munches-on-dandelions knows works because they did it successfully.  It also took the opportunity to open up a whole new world for Frustrated-with-dandelions.  A world where dandelions enter the kitchen as beloved guests.  Frustrated-with-dandelions may not think this is a good idea at this time, but Frustrated-with-dandelions now has had a positive experience.  They got an answer, they feel respected, and maybe next time they see someone talking about dandelion salad they might be willing to try it.



But what if it's a really bad idea?  Like super-duper-worst-idea-ever kind of idea?

I have a challenge for you:

Let's pretend someone wants to make a roof out of cardboard.

Can you say it's a bad idea but, and get this bit, it's important, say it in a positive way that encourages them?  

Cardboard roof? How about the whole house being made of cardboard ? And I am not talking those houses we all made out of refrigerator boxes when we were kids. Check this out:    it has been done.

Travis Johnson wrote:This is a hard thing for me, because I grew up farming.

For instance chainsaws, I have been logging since I was 15 years old, almost 30 years now. When people ask about safety chain, or a chainsaw to buy, I have some powerful opinions on that stuff...based on my experience...but I must step back and think that these people do not have 30 years of experience either.

Sometimes I reply, but lately I have been finding myself staying mum because I am not sure if I should speak up or not. Should I? I got 30 years operating a chainsaw so I got some pointers for sure, but then again it is not in the same capacity as me either.

By all means, share your experience, but share it as your experience rather than as "You should do what I say." So like, in the chainsaw example, if you have extensive experience, you can say "I used to use [or Several people I know use] a such-and-so chainsaw, but I found that it was difficult to xyz, or I had a couple of close calls because of xyz [or whatever] so now I use this-other-type, and I'm much happier with it. It allows me to..."

Thank you for this thread, again, I'm learning so much!

It takes some unlearning of stuff for people like me. For example on some scientific-minded forums sharing your own experience is ridiculed, even when it's about something subjective. I've learned to find a newspaper article that says what I wanted to say when what it comes down to is that it's just my opinion. I really do think it's more honest to just say this is my opinion/ my experience and I'm glad to learn this new way of writing and unlearn the old one.

Rebecca Norman wrote:

Travis Johnson wrote:This is a hard thing for me, because I grew up farming.

For instance chainsaws, I have been logging since I was 15 years old, almost 30 years now. When people ask about safety chain, or a chainsaw to buy, I have some powerful opinions on that stuff...based on my experience...but I must step back and think that these people do not have 30 years of experience either.

Sometimes I reply, but lately I have been finding myself staying mum because I am not sure if I should speak up or not. Should I? I got 30 years operating a chainsaw so I got some pointers for sure, but then again it is not in the same capacity as me either.

By all means, share your experience, but share it as your experience rather than as "You should do what I say." So like, in the chainsaw example, if you have extensive experience, you can say "I used to use [or Several people I know use] a such-and-so chainsaw, but I found that it was difficult to xyz, or I had a couple of close calls because of xyz [or whatever] so now I use this-other-type, and I'm much happier with it. It allows me to..."

I get what he is saying though.  As a (retired) very well  trained and experienced manual therapist in very specific methods of pain relief and such, I used many "tools" in my "tool belt". It can be hard to not just tell someone that in order to get best results the way i am telling them is the best way. After all, most of the people that came to me, came to me after they exhausted all other methods even going to doctors who let them down. But I still had to be careful as how I could say it and approach it. I knew I was not a doctor and could not prescribe anything,  yet they came to me for help and I had a pretty good handle on most situations, and if I didn't,  I had to be honest and unfortunately let them down as well.    But I had a certain skill and for lack of a better/simpler explanation, I had good intuition.  But I always had to offer advice of self-care to do at home in historical or personal contexts of experience  of how I would apply an exercise or herbal/nutritional supplement.   Or how they have been applied historically for others. I could never tell them they had to do it or had to do it my way even if I knew it was what was going to work for them, by experience.  It was always in their own hands.  

If I knew you in person and respected your authority, I'd be happy to listen to you when you said "I know best, this is what you should do." I do that in real life all the time.

But when I'm on an internet forum, I have no way of evaluating your authority or experience. You may have said on an earlier post that you have all these years of experience or training or research or whatever, but when I read your suggestion, I won't remember that. So if you ARE in fact an expert, don't depend on us other readers to know that. Refer to it as necessary in your post. "I've done quite a lot of research on natural building materials, and when we tried cardboard, this was our result." Or"I've done quite a lot of research on natural roofing materials, and from what I recall the people at such and so tried it and this was their result." or "I'm a roofer, and I like such and so material because it is waterproof at X angle, and it is heavy enough not to blow away. I use cardboard as mulch and I like how it absorbs water and rots within a season, but these are not qualities I want in a roofing material."

The main thing is, try not to tell the person directly they are wrong. Instead, tell the world what you know about the topic, and let them judge for themselves, which is what they'll do anyway, right?

(By the way, in Ladakh for the past 10 or 20 years, people actually DO use cardboard as one of the layers in their roofing materials, but that's not relevant to the topic of gently telling people on the forum they are wrong)