BS: Venn Diagrams - WHY?

Subject: BS: Venn Digrams - WHY?
From: Geoff the Duck
Date: 18 Mar 04 - 06:56 AM

Just a passing thought. When I was at junior school we spent weeks working on Venn Diagrams, drawing overlapping circles and sorting items into ones which were round, blue, red, square etc, with the red squares in an overlap between the "Red" circle and the "Square" circle.
This morning on a TV "Schools Programme", a bunch of inhabitants of a space station ended up sorting their store of biscuits using the same technique.
WHY?
In the thirty odd years since I learned to draw a Venn Diagram, I have NEVER happened across a circumstance where I have needed to use the mehod for ANY purpose whatsoever. (I use trigonometry and geometry on a regular basis for practical tasks. I have even used quadratic equations for real).
I am just curious to know if anyone out there has ever been involved in using them for a real porpose - I do not include the use by teachers purely because it is listed as a topic that they must teach.
I suppose my questions are
"Are Venn diagrams taught because somebody thinks that they are useful?" And if so - for what?
"Are they just taught as an exercise to make children think?" If so - what trait do they strengthen?

I welcome your thoughts on the topic.
Quack!
(Geoff (the) Duck)

Subject: RE: BS: Venn Digrams - WHY?
From: Noreen
Date: 18 Mar 04 - 07:13 AM

To make children think, Geoff, about properties and categories and how these are not always exclusive but can be inclusive or overlapping.
It's also about sorting information to make it useful, about why you put certain things into certain categories.

I like your brackets \:0)

Subject: RE: BS: Venn Digrams - WHY?
From: Wolfgang
Date: 18 Mar 04 - 07:26 AM

I use them often in teaching, no, not in your sense of teaching Venn diagrams (I don't teach them) but in Noreeen's sense of making other things (errors in thinking and probability estimation) clearer.

Wolfgang

Subject: RE: BS: Venn Digrams - WHY?
From: Shanghaiceltic
Date: 18 Mar 04 - 07:29 AM

I sometimes use them in business presentations to indicate such things as overlaps between our company, agents and customers.

Or I use them to look at strengths and weakness of products and organisations when I do not want to do a 4 part swot analysis. It helps show overlaps very visually rather than using a list of bullet points.

Subject: RE: BS: Venn Digrams - WHY?
From: DMcG
Date: 18 Mar 04 - 07:55 AM

The problem I have with Venn diagrams is that once you have more than about four sets to deal with and you want to explicitly show certain overlaps are empty they become unworkably messy. Even if you cheat and allow the sets to overlap but put in an explicit empty marker (such as filling the overlap with white) the whole thing gets out of hand pretty rapidly.

Subject: RE: BS: Venn Digrams - WHY?
From: Bee-dubya-ell
Date: 18 Mar 04 - 07:59 AM

Venn diagrams are graphical representations of the fact that two or more groups may have similar and disimilar characteristics. I don't sit down and draw Venn diagrams, but having been exposed to them allows me to conceptualize relationships in a graphical manner which often makes it easier for me to get a grasp those relationships.

Bruce

Subject: RE: BS: Venn Digrams - WHY?
From: DMcG
Date: 18 Mar 04 - 08:08 AM

*** MAJOR THREAD DRIFT HERE ***

sometimes use them in business presentations

For years I have suspected that the only reason business ideas like SWOT charts (Strenghs, Weaknesses, Opportunities and Threats) and PEST analyses (Political, Economic, Social and Technological) have four aspects is that anyone can draw a 2x2 grid but one with five terms is difficult and three is not a great deal better.

Anyone care to second me on that?

Subject: RE: BS: Venn Digrams - WHY?
From: mooman
Date: 18 Mar 04 - 08:22 AM

I use them extensively to illustrate that the company structure is shite and that everyone is partially duplicating someone else's job as well as doing their own. But so far without success.

Peace

moo

Subject: RE: BS: Venn Digrams - WHY?
From: Geoff the Duck
Date: 18 Mar 04 - 08:28 AM

I always thought they used such acronyms was because some halfbrain thought they sounded "snappy", and not because any of them produced a useful result. In other words - think up your acronym and then try to fit some words to the letters... A bit like the scientist's - Draw your graph first and then try to fit results around the line.
Quack!
GtD.

Subject: RE: BS: Venn Digrams - WHY?
From: Rapparee
Date: 18 Mar 04 - 08:28 AM

I use them to illustrate data structures and to attempt to render otherwise difficult-to-visualize cencepts.

Also, if you diagram "some A is B, some C is B, but no C is A" you can end up drawing Mickey Mouse.

Subject: RE: BS: Venn Digrams - WHY?
From: GUEST,Shlio
Date: 18 Mar 04 - 08:33 AM

They're used to represent probability and annoy everyone forced to do a statistics GCSE. BUT - they don't have to be circular. I myself draw triangles...

Subject: RE: BS: Venn Digrams - WHY?
From: Geoff the Duck
Date: 18 Mar 04 - 08:34 AM

Is that Mickey Mouse by Picasso?
Quack!
GtD.

Subject: RE: BS: Venn Digrams - WHY?
From: DMcG
Date: 18 Mar 04 - 08:41 AM

I'm with you there, Geoff! But I'm also looking at the reason they are four-letter snappy hb ideas, not three or five letter ones.

Vainly trying to tie this back to the thread, the Venn diagrams of the sets of Political, Economics and Social things, for example, would have large overlapping sets, but PEST charts allow for no such overlaps. The result is than anything in the common set has to be dumped on one side or the other, making a tool of some limited value almost entirely useless.

Subject: RE: BS: Venn Digrams - WHY?
From: Rapparee
Date: 18 Mar 04 - 09:05 AM

Which is downright silly, 'cause eventually EVERYTHING touches!

Subject: RE: BS: Venn Digrams - WHY?
From: GUEST,Jon
Date: 18 Mar 04 - 09:19 AM

I've not used them since 1st or 2nd year secondary school (what was then called "modern maths" was not taught in the next school I moved to - a move from N Wales to Kent) but can imagine they can be useful in teaching computer type boolean logic. (AND OR NOT).

Jon

Subject: RE: BS: Venn Digrams - WHY?
From: Amos
Date: 18 Mar 04 - 09:29 AM

They are useful in making a thought process which you DO use all the time explicit and showing a way to make it rigorous.

I don't do multiplication by longhand anymore either for most small uses, hving learned my times tables many years ago.

But I can do it if needed, and it's nice to know there's method to what has become insitinctual.

A

Subject: RE: BS: Venn Digrams - WHY?
From: Strick
Date: 18 Mar 04 - 09:35 AM

I don't use Venn diagram per se anymore, but the ideas and the general set theory they describe are the key principles driving most of the world's modern databases. Those of us who went through "modern math" 35-40 years ago actually have less trouble learning how to program in database environments or do complicated data analysis than the young kids who weren't brought up with these ideas.

Subject: RE: BS: Venn Digrams - WHY?
From: GUEST,heric
Date: 18 Mar 04 - 11:55 AM

Just a few weeks ago I had the small pleasure of explaining to my ex that she doesn't understand the things I do because our moral codes do not overlap on a Venn diagram. It can add a visualk perspective to otherwise bland commentary.

Subject: RE: BS: Venn Digrams - WHY?
From: Jeanie
Date: 18 Mar 04 - 11:56 AM

I loved Venn diagrams ! I was taught them as part of maths lessons in around 3rd year (Year 9) of senior school. I was not, and still am not, mathematically inclined, and the rest of maths was always a struggle, but with Venn diagrams, I was one of the few in the class who really 'took' to them. Apart from anything else, it made a pleasant change to be the one the teacher picked to do the examples on the board and get it right !

I see one of the most important uses for Venn diagrams, and for the kind of thinking they require, to be in the field of logic, language and philosophy, more so than in the realm of maths (as in logic exercises of the "all cats are black" type). I've never actually *drawn* a Venn diagram in the past 3 or more decades, but I believe I may often "draw" a verbal/visual Venn diagram in my head, when working something out, without being fully aware that that is what I am doing. I went on to study languages, and certainly the thought processes learned through Venn diagrams helped in deciphering all those French and German philosophers whose learned tomes we had to read, not to mention the linguistic theories of Chomsky and his ilk.

- jeanie

Subject: RE: BS: Venn Digrams - WHY?
From: Bill D
Date: 18 Mar 04 - 01:50 PM

wonderful, Jeanie!...that use: to work thru the logical inconsistencies of a situation and sort out good rhetoric from bad, is one that should be TAUGHT to every student...it doesn't deal with every detail, but it is a great way to reduce the BS!

Subject: RE: BS: Venn Digrams - WHY?
From: Schantieman
Date: 18 Mar 04 - 02:34 PM

I agree that Venn diagrams (I wonder who Venn was, btw? We used to have a Mr Venn at school but I don't suppose it was him.) help to visualise these relationships and help kids to learn to think - a jolly useful skill. But - aren't they also an introduction to 'set theory' which I think is a major branch of maths?

Steve

Subject: RE: BS: Venn Digrams - WHY?
From: jeffp
Date: 18 Mar 04 - 02:36 PM

Bill, the problem is that the schools today (I'm speaking primarily of the Howard County Public Schools, since that's what I have recent experience with) don't seem to want to teach students to think critically. That would make them question their teachers and be much tougher to deal with. The schools are much more comfortable dishing out information and having the students regurgitate it back to them on tests. Other than that, they should just sit quietly and pose no discipline or other problems.

A far cry from my school days.

jeffp

Subject: RE: BS: Venn Digrams - WHY?
From: Wolfgang
Date: 18 Mar 04 - 03:02 PM

John Venn (bio and picture)

Wolfgang

Subject: RE: BS: Venn Digrams - WHY?
From: Grab
Date: 18 Mar 04 - 03:27 PM

Geoff, there's a lot of stuff you learn in school which you never have to use on a regular basis. Let's be honest here, I've never had to know about what forms a hanging valley, or what living conditions were like in the 18th century. I've not spoken any French since school or German since uni. And most people would have no use for trig or quadratic equations either.

The purpose of all this stuff is to give kids a basic standard set of facts and concepts which can then be applied as needed through their lives. The fact that everyone only uses maybe a quarter of the facts and concepts they learn at school is irrelevant, because you've no way of knowing in advance which quarter will be needed. So all the kids learn the same stuff, until they're old enough that they can choose subjects.

Graham.

Subject: RE: BS: Venn Digrams - WHY?
From: Nerd
Date: 18 Mar 04 - 03:44 PM

I actually use a variation of the Venn diagram in teaching folklore classes. I want to establish that all of us are simultaneously members of more than one cultural group, each of which shares folklore. So the students in my class will have some folklore that overlaps with everyone else in the class ("a stitch in time saves nine" is something that most of them will know), and some folklore that overlaps only with a few of the others or none at all (family lore, hobby group lore, etc).

A diagram is helpful because usually students think of ethnicity and sometimes religion as the only relevant cultural groups they belong to "I'm a Mormon," or "I'm Italian." But they don't think about the fact that their culture is not the same as that of other Italians or other Mormons, because they are ALSO a theatre arts major, science fiction fan, from southern New Jersey, and nineteen years old (for example), each of which is a cultural group that overlaps with all the others. Of course, you can't fit ALL these groups on a venn diagram, but it is a useful starting place.

Subject: RE: BS: Venn Digrams - WHY?
From: Amos
Date: 18 Mar 04 - 03:51 PM

Top Ten Ways to Use Venn Diagrams

Subject: RE: BS: Venn Digrams - WHY?
From: Amergin
Date: 18 Mar 04 - 03:54 PM

Does anyone have an example of a venn diagram? I have never heard of it before...

Subject: RE: BS: Venn Digrams - WHY?
From: Strick
Date: 18 Mar 04 - 03:58 PM

Short answer:

Venn Diagrams

For more detail the website Amos references is pretty through.

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST,Pete Peterson
Date: 18 Mar 04 - 04:36 PM

Well, I've actually used them in speech; we were putting a group together (it later became Ben Borscht and the Beats, of Clifftop fame ((??!!)) but was first named Otter Chaos. But i digress. We had four members, and I said something like "I don't think we'll have any trouble finding material; the set A intersection B intersection C intersection D should have lots of members" and everybody knew just what I meant.

PETE

Subject: RE: BS: Venn Diagrams - WHY?
From: Mr Red
Date: 18 Mar 04 - 06:04 PM

Ah! - when we wus a school - I used to dream about being taught Venn Diagrams. I had to wait till college to be let into the secret.

Is this a case of "Now" and "Venn"

I'll get my coat and Duck...........

Subject: RE: BS: Venn Diagrams - WHY?
From: Strick
Date: 18 Mar 04 - 06:32 PM

"I'll get my coat and (Geoff the) Duck?"

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST
Date: 18 Mar 04 - 06:33 PM

What are you going to do with your duck after you get it?

Subject: RE: BS: Venn Diagrams - WHY?
From: Joe_F
Date: 18 Mar 04 - 06:42 PM

When I was a freshman at Caltech in 1955, I drew a Venn diagram with myself & my two best friends in the intersection of my student house, the radio hams, and the honor section. All my other friends, with one exception, were in at least one circle. A primitive sociogram, I suppose.

Subject: RE: BS: Venn Diagrams - WHY?
From: Geoff the Duck
Date: 18 Mar 04 - 07:11 PM

Is the logo for the Olympic games a Venn Diagra? And if so - What are the sets?
Quack!
GtD.
p.s. I got my Duck and I'm keeping her!

Subject: RE: BS: Venn Diagrams - WHY?
From: Geoff the Duck
Date: 18 Mar 04 - 07:12 PM

m

Subject: RE: BS: Venn Diagrams - WHY?
From: Noreen
Date: 19 Mar 04 - 05:20 AM

John Venn was born in Hull.

:0)

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST
Date: 19 Mar 04 - 06:38 AM

All those bloody circles - it's enough to make you start morris dancing going round in circles waving ribbons in the air..

Subject: RE: BS: Venn Diagrams - WHY?
From: Helen
Date: 19 Mar 04 - 06:51 AM

Well I can honestly say that I use Venn diagrams (in my head) every day, now that I use the Internet every day. (Seriously!)

When I was studying to be a librarian I was taught how to do database searches and did a search way back in 1980 or so on a database in San Francisco while sitting in a library in the south of New South Wales, Australia. I did the search based on a Venn diagram I had to draw beforehand. The access costs then were phenomenal so we had to think out our search prior to being allowed access to the database. One of the criteria which the teacher was looking for was a good Venn diagram of the search terms.

The search process was explained very clearly as a Venn diagram. I am looking for "this AND (this OR this) but NOT this".

Every time I do an Internet search I am subconsciously putting my search terms into that thought process.

Funnily enough, the last time I mentioned a Venn diagram was about 2 weeks ago - 5 times in one week - when I taught 5 different pre-trades classes how to search the 'Net effectively.   'If you are searching for something about cars you could search for cars OR "motor cars" OR automobiles.'   'If you want something on computer games you need to look for computer AND games' although searching on Google makes it easier by using the double quotes for phrases.

So yes, I use them all the time now.

Helen

Subject: RE: BS: Venn Diagrams - WHY?
From: Alice
Date: 19 Mar 04 - 02:46 PM

Born in Hull, died in Cambridge.
Wow. Hull creeps in everywhere on the Mudcat ;-)

Subject: RE: BS: Venn Diagrams - WHY?
From: Mr Red
Date: 20 Mar 04 - 06:28 AM

they're always going round in circles in 'Ull.

Just a thought but why are all our Kingstons upon something (Hull, Thames etc)

Subject: RE: BS: Venn Diagrams - WHY?
From: BanjoRay
Date: 20 Mar 04 - 08:18 AM

Because Kings' towns needed to be on a river so they could make a quick escape if they were being attacked by Venn diagrams.
Ray

Subject: RE: BS: Venn Diagrams - WHY?
From: Helen
Date: 20 Mar 04 - 08:34 AM

They would circle the enemy?

Helen

Subject: RE: BS: Venn Diagrams - WHY?
From: Amos
Date: 20 Mar 04 - 08:47 AM

They thought they were being "set" upon. But it was only a theory. But Venn again, it might have had some merit.

Seriously though, Venn analsyis is almost like breathing, it is so basic, If there is any question why one uses the diagrams (or might) he should do a Venn diagram of that problem!

A

Subject: RE: BS: Venn Diagrams - WHY?
From: Mr Red
Date: 20 Mar 04 - 11:48 AM

BanjoRay -

You mean Kings were being Vennerated?

Subject: RE: BS: Venn Diagrams - WHY?
From: Jeanie
Date: 20 Mar 04 - 12:37 PM

"British towns named Kingston are on rivers and have the river in their name."
"Most, but not all, British towns are on rivers."
"Some British towns, not named Kingston, are on rivers and have the river in their name."
"Some British towns are not on rivers and are not called Kingston."
"Some British towns are on rivers and do not have the river in their name."

Your homework exercise, my friends, is to draw Venn diagrams to illustrate.

- jeanie (who is SAD enough to actually be seriously contemplating doing this !)

Subject: RE: BS: Venn Diagrams - WHY?
From: Mrs.Duck
Date: 20 Mar 04 - 12:54 PM

Sometimes I think my husband has too much time to spare while I slave away at school teaching Venn diagrams (of course we use REAL circles not just boring old drawn ones. I like doing ones with three circles with my six year olds! Of course we start with one and then build up to three and I never tell them to overlap them they work that out for themselves - develops problems solving skills. I have a book I will let Geoff read all about cognitive development.
I'll get my white coat.

Subject: RE: BS: Venn Diagrams - WHY?
From: Strick
Date: 20 Mar 04 - 05:07 PM

"The search process was explained very clearly as a Venn diagram. I am looking for 'this AND (this OR this) but NOT this'."

Exactly! Very powerful tool for most forms of data analysis.

Funny you should mention it, Jeanie, but while trying to remember some old symbolic logic (a PhD quoted on another thread fell into the trap of using false syllogisms), I came across this website. Note that at one point it explains the whole in Venn diagrams!

Categorical Syllogisms

Subject: RE: BS: Venn Diagrams - WHY?
From: Jeanie
Date: 21 Mar 04 - 04:33 AM

Thanks for the link, Strick. What an excellent website ! Have you looked at the link to the "Syllogism Evaluator" at the bottom of the page ? That looks like it's going to be great fun to do. I had forgotten just how much pleasure I can get from working out this kind of thing.

The whole thread has set me wondering: Where does a liking for (and an ability in) solving particular kinds of puzzles begin ? Vice versa: where does an aversion to particular kinds of problem-solving begin ? I know that it's possible, through practice, to create and re-create new pathways in the 'wiring' of the brain, so that new skills and ways of thinking can be learned; that success breeds success, and you enjoy doing what you are good at, but what I am talking about here is something that goes deeper and earlier in life than that. Is it down to inborn personality differences or the result of very early experiences, or both ?

For instance: Some people are very good at, and gain tremendous pleasure from doing complicated jigsaw puzzles, and will happily spend their leisure time on them. Personally, I can't see the point. Likewise with 'wordsearches'. Both of those kinds of puzzles are dealing with what is already there and the pleasure of finding it and creating order. Logic puzzles and crosswords, on the other hand, are dealing with the exact opposite: what is NOT there and the pleasure of the long and winding internal road towards finding it.

What I am trying to say is that it doesn't seem to me that there is a straight classification between people who prefer "verbal" puzzles or "visual" puzzles. I don't think it can be divided between differences in male and female thinking, either, or different levels of intelligence. I wonder where the origin is ? Is it that because of individual circumstances some people learn to survive, from an early stage, by relying more on the internal and some more on the external ? For instance: because of my ill health as a newborn, baby and toddler, I spent long periods of time alone and apart from my parents. For sheer survival, I had to make sense of the world and gain comfort and pleasure by internal thought processes and I can remember having very complex 'thought conversations' with myself at a very early age. This is rather an extreme example, but I wonder how far it is true to a lesser degree for everyone, and is at the origin of their ability in, and preference for, internal or external problem-solving ?

Now, here's another conundrum: What is it in the psyche or babyhood experiences of some people that makes them ENJOY collecting train and bus numbers ????? That's something I have never been able to understand. I know there are some enthusiasts here in Mudcat and I'd be really interested in an explanation of what they gain from it.
(Not criticizing or mocking, you understand, just interested).

- jeanie

Subject: RE: BS: Venn Diagrams - WHY?
From: Mr Red
Date: 21 Mar 04 - 05:42 AM

As I sit here sucking on my Polo Mints (or Life Preservers for you older Yanks) I am swiftly coming to the conclusion that by masticating three Polos

Venn Sucks

Subject: RE: BS: Venn Diagrams - WHY?
From: Mr Red
Date: 21 Mar 04 - 05:43 AM

LOL jeanie
Go for it I say........

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST,leeneia
Date: 21 Mar 04 - 09:52 AM

It sounds like a Venn diagram might be helpful to the management of the fabric store where I work. A customer pointed out that we have fabrics for babies and kids, fabric for male kids, but no fabric for female kids.

Subject: RE: BS: Venn Diagrams - WHY?
From: Peace
Date: 21 Mar 04 - 09:22 PM

1) Suggest the female kids have sex changes
2) Dress the kid funny
3) Give the female kid a Venn diagram to wear
4) Ask Venn

Subject: RE: BS: Venn Diagrams - WHY?
From: Peace
Date: 21 Mar 04 - 09:23 PM

Venn Diagrams - WHY?

So we can confuse by using pictures what we have confused by using words.

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST,noddy
Date: 22 Mar 04 - 04:10 AM

"All lipe shends are umty but are all umpty shends lipe"

This was a question from my maths book, it certainly made me think and understand Venn Diagrams.

PS Little Hawk I took special care typing this one......

Subject: RE: BS: Venn Diagrams - WHY?
From: Snuffy
Date: 22 Mar 04 - 09:56 AM

Kingston on Thames
Kingston on Hull
Kingston on Tario

Subject: RE: BS: Venn Diagrams - WHY?
From: Peace
Date: 22 Mar 04 - 12:18 PM

Dang, Snuffy, I just got it. HA HA

Read it twice before and wondered where the heck Tario was. LOL

Subject: RE: BS: Venn Diagrams - WHY?
From: Stilly River Sage
Date: 22 Mar 04 - 02:37 PM

Geoff, thanks for this thread! I knew how to use the diagram but didn't know what it was called. I was able to call on this new-found knowledge just today when writing to a different list.

You learn something new everyday--and as often as not, it's over here at Mudcat!

SRS

Subject: RE: BS: Venn Diagrams - WHY?
From: Schantieman
Date: 22 Mar 04 - 04:51 PM

I say, I say, I say
My wife went to Kingston last week

Jamaica?

No - she went of her own accord.

;-)

S

Subject: RE: BS: Venn Diagrams - WHY?
From: Mr Red
Date: 23 Mar 04 - 01:47 PM

Leenia - Zwicky's Morphology would work better the fabric choices. It is more like a pile of kiddies blocks. Imagine the eastern side of each brick is written an age category. Any one vertical column of would have one age.
tot, kid, teen, twenty, married, ditto with kids, grandparents, silver sewers, dotage.
the north face of each brick could be gender, again same in coumns, differing from column to column.
male, female, androgenous, TV, neutral
and looking down the tops would bear the patterns
tartan, lines, paisley, floral, cloudy, geometrical, William Morris, etc

Now that pile of bricks has a brick for every combination of those groupings above.

This is just an aid to visualise a mathematical process in tangible imagers. But some of us see it better that way.

Yer venn diagram gets a bit difficult to complete combinations in more tha two dimensions. This at least works for three. After that you have to imagine multiple piles of bricks.

There could be mortar bricks than meets the eye......

Subject: RE: BS: Venn Diagrams - WHY?
From: McGrath of Harlow
Date: 23 Mar 04 - 07:13 PM

We didn't have Modern Maths when I was at school. (So my equivalent question is "Why did I spend all that time learning to deal with simultaneous equations, when I've never used a simultanenous equation in the rest of my life?)

Perhaps if we could work out a way of using Venn diagrams here it could help in the "What is Folk" threads. Instead of ending up going round in a circle, we'd end up in going round in overlapping circles.

Which just set me thinking - couldn't they be a way of making circle dancing a lot more exciting?

Subject: RE: BS: Venn Diagrams - WHY?
From: Strick
Date: 23 Mar 04 - 07:26 PM

"(So my equivalent question is "Why did I spend all that time learning to deal with simultaneous equations, when I've never used a simultanenous equation in the rest of my life?)"

You DON'T use simultaneous equations anymore? I thought everybody did.

Subject: RE: BS: Venn Diagrams - WHY?
From: Amos
Date: 23 Mar 04 - 07:39 PM

Come, come!! How do you think you manage to get out of bed each morning? You think that's a single-value computation? Nononono!

A

Subject: RE: BS: Venn Diagrams - WHY?
From: Kaleea
Date: 24 Mar 04 - 03:09 AM

Surely we musn't forget the most important potential of the Venn Diagram--
a potential illustration/visual aid for the next radio address of Bubba"prez"bush.

   OR: an example given by Bubba"prez"bush in a recent speech in reference to the most often used forms of birth control in these modern times.

Subject: RE: BS: Venn Diagrams - WHY?
From: Mr Red
Date: 24 Mar 04 - 07:19 PM

you mean all those circles are an allegory on the coil?

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST,Jon
Date: 24 Mar 04 - 07:54 PM

Sidetracking, but thinking of Amos' line (I'm not implying a set here just descision making), it can be interesting to say give instructions make a cup of tea. I mean for example that could include a loop something like "while water is not hot enough continue to apply heat". There is much we do naturally but take for granted. In that case we would all say wait till the kettle has boiled.

As for threads and sets, every post in this thread belongs to a group of posts but are only posts with an ID 679988. Few of us would ever think of the (say, pretty sure it is SQL Server here) SQL behind that when reading.

We are quite remarkable at using processes subconsciouly.

Subject: RE: BS: Venn Diagrams - WHY?
From: dianavan
Date: 24 Mar 04 - 08:32 PM

Venn diagrams are one way of organizing your thoughts and ideas but not all people think the same way. Some people prefer point form. I prefer making a web because that more accurately describes my thought process. Students should be exposed to all three methods (maybe more) and encouraged to use what works best for them.

d

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST,John Venn's sister
Date: 31 Mar 04 - 06:08 AM

Today's John Venn is a bloodsucking vulture. He locked his mother into an Altzheimer's ward so he can cash in on her savings. His sister Vicky Venn is forging checks to pay for the lawyer's fees to have her locked away eternally.

Subject: RE: BS: Venn Diagrams - WHY?
From: Donuel
Date: 31 Mar 04 - 07:06 AM

Well gee, we use them for federal goverment presentations !?

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST,Joerg
Date: 31 Mar 04 - 09:44 PM

Geoff -

To answer your question: Yes, as far as I know there is ONE practical application for Venn diagrams (BTW I seem to be older than you because I first was introduced to "Euler" diagrams and then learned that Venn diagrams were the same): The so-called KV (Karnaugh-Veitch, not sure about the spelling) diagrams. They can be used to convert - uhm - truth tables (?) into boolean expressions.

Since I neither know whether you are familiar with boolean algebra nor am sure about my english terminology let me give you an example:

Should you marry her? You have three inputs:

A: She is pretty. (1=yes, 0=no)
B: She is rich. (1=yes, 0=no)
C: You love her. (1=yes, 0=no)

You want to obtain one output:

D: You should marry her. (1=yes, 0=no)

Now you write down all possible input combinations as a table and assign an output to them at your will, for example:

ABC D
-----
000 0
001 1
010 0
011 1
100 0
101 1
110 1
111 1

If you are familiar with KV diagrams you can convert this to the boolean equation

D = (A and B) or C

In human words: You should marry her if she is pretty AND rich OR if you love her.

The boolean form is for example needed when you want to make an electronic circuit that gives you this advice or when you want to program the logical decision. The example I chose was once sold as a demo construction set for logical gates ("marriage indicator").

Enjoy

Joerg

Subject: RE: BS: Venn Diagrams - WHY?
From: Amos
Date: 01 Apr 04 - 01:23 AM

Experientially, that should be D= C AND (A or B) I believe...

A

Subject: RE: BS: Venn Diagrams - WHY?
From: dianavan
Date: 01 Apr 04 - 01:48 AM

I thought it was D = C AND (A or B)

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST,Joerg
Date: 01 Apr 04 - 08:38 PM

As I said - at your will. ;-D

Subject: RE: BS: Venn Diagrams - WHY?
From: GUEST,ET
Date: 28 Apr 04 - 05:04 PM

Venn Diagrams can now be used to help you see patterns in your database (if you have one) that you may not have know existed by just looking at tables.

If you go to http://www.setgraph.com/SearchDemo.htm you can add Venn diagrams to your Google searches for free and perhaps understand the benefits of Venns. This architecture is actually used by companies now to do things from profile customer buying habits, to stock screening, to identifying trends in their business.