BS: Venn Diagrams - WHY?

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: 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: 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: 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: 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: 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: 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: 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: 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: Rapparee
Date: 18 Mar 04 - 09:05 AM

Which is downright silly, 'cause eventually EVERYTHING touches!

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: 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: 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: 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: 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: 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: 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: 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 - 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: 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: 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: 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: 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)