Randomly assign x number of students to x number of workshops where students do not meet the same co-student

[yazoo]

Dear all

I'm familiar with basic Excel functions but when it somes to solving this specific need I dont have a clue of how to fix it. I have search the internet and I have found plenty of examples where I can assign people on a list to a number of groups. But I need a twist to that

I have a list of x number of students (varies from class to class)
I have x number of workshops (varies from class to class)
All students must meet all other students in a workshop, but never the same student more than once. In other word: All students on the list must be randomly put into workshops with another student but a student must never meet another student they have already been in a workshop with.

I'm blank so any help or guidance is appreciated.

/Anders, Denmark

EDIT:
The number of participants in a workshop must be variable. It could be 2, 4, 5, 6 etc.

 

[mikerickson]

Is the number of students the same as the number of workshops.
If S is the number of students and W is the number of workshops, .. if S <= W , then a pair (or more) of students will be in the same workshop twice (or more).

At the limit (S=W+1) this acts like a round-robin sports tournament where each team plays each other team once and only once. (student=team workshop=game)

The algorythm that I use for that is a two sided table with people sitting across from each other. every person shifts one chair to the right one seat, except for one person who doesn't move

A B C D
E F G H

A D B C
E F H D

A E D B
F H D C

' etc

 

[yazoo]

Thank you very much for your reply
No, the number of students is not always the same as the number of workshops
I do understand that in some cases might be in the same workshops - if S<=W
I understand your two sided table approach. Good point.

The number of workshops could be triggered by number of (paired) students.

My latest case was 18 students and 9 workshops

Kind regards
Anders

 

[mikerickson]

With your 18 students and 9 workshops...

Is one pairing (e.g.Bob and Carol) one workshop or would the 9 pairings

Bob-Carol
Steve-Dan
...

count as one workshop?

 

[yazoo]

Hmmmm
One pairing, e.g. Bob and Carol is assigned to one workshop. Steve and Dan to another workshop that takes place at the same time as the workshop with Bob and Carol. The 9 workshops is a series of workshop events.

The first workshop pairs the students in to teams of two
The second workshop also pairs the students into teams of two, but no student must be paired with a student they were paired with in the first workshop
The third workshop also pairs the students into teams of two, but no student must be paired with a student they we paired with in workshop one and/or two
And so it continues

Example:
Students = 4 (Bob, Carol, Ann and Paul). Then the manual task is quite doable. But if it is 9 student its easy to loose track if done manually.

Week 1/Workshop 1	Week 2/Workshop 2	Week 3/Workshop 3	Week 4/Workshop 4
Bob & Carol	Carol & Ann	Carol & Paul	No need, all have worked together and not met each other twice
Ann & Paul	Bob & Paul	Bob & Ann

<tbody>
</tbody>

Does this make sense / Answer your question?

With your 18 students and 9 workshops...

Is one pairing (e.g.Bob and Carol) one workshop or would the 9 pairings

Bob-Carol
Steve-Dan
...

count as one workshop?