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[Encyclopaedia] Randomly - By chance

Meanings:

  1. Lack of information
  • You do something randomly when you do it without reflecting upon it, or without having information.
     
  • A fact or a situation is defined to be random when you don't have enough information in order to know how it will end up .
  1. Lack of reason:
  • You do something randomly when you do it without thinking very much, without a reason
  • ­ A fact that happens independently from humans' will is a random fact;
     
  • An event which happens unexpectedly, not thought or without will.
     
  1. Action allowing us to chose between equal situations
     

Examples:

  • "I randomly picked one candy from a bag full of candies". This phrase is random because I didn't know the flavours of the candies (meaning 1).
     
  • I answered to the questions randomly because I hadn't studied (meaning 1).
     
  • I picked  a random card from the deck (meaning 1).
  • ­"By chance I went to the cinema the same day as last year". Not on purpose I went to the cinema the same day as the previous year (meaning 2).
     
  • ­ We met at the cinema by chance (meaning 2).
  • ­ I threw a stone randomly (meaning 2).
     
  • ­For the role of Peter Pan, they chose a child randomly, because the children were all good (meaning 3).
     
  • ­ She chose a dress randomly because they were all the same (meaning 3).
  • ­By choosing between two equal things you act randomly (meaning 3).
     
  • ­ .If you have to chose  between 20  wrapped presents, and you don't have enough information to chose the one you like most, then you will have to chose randomly (meaning 1+3).
  • ­ That happened only by chance (too generic phrase, it could have the meanings 1, 2, or 3).
     

Synonyms and contraries:

  • Contraries:
    • not randomly, sure, usual 1
    • predictable [6 - 14]2
  • ­       Synonyms:

    • without reflecting on what you do,

    • Thoughtlessly,

    • without thinking about it,

    • unpredictable,

    • fortuitous,

    • accidental,

    • occasional,

    • involuntary

Related Weblabspaedia items:

Not randomly - not by chance, predictable, unpredictable.
 

Curiosities / Anecdotes / Miscellanea / History:
 

  • One day, in class, we talked about how the teacher chooses pupils for oral tests: sometimes she has a reason to chose someone, other times she does not, so se does an extraction. The problem is to find a fair way to do the extraction.
     
  • According to someone choosing situations can be not random; whilst other think they can be random. (the teacher may chose not randomly a pupil for interrogation, but other pupils will think she choose randomly)
     
  • ­ The destiny is a  fortuity of life.
  • ­ If I roll two dices, the sum of the number I get is random; however, if I roll them many times, the histogram of the results has a well defined shape; we have to try if it is always the same.


 

    Each one of us threw 100 times a couple of dices, then we put them together with EXCEL and we did a graph: here it is what we obtained, a sort of bell; number seven results to be more probable  then the other numbers; the probability decreases with smaller and bigger numbers.

    Each of us tried to explain this.

    This is the explanation given by TEO:  number 7 is has the highest probability to be extracted, because there are more combinations of the two dices that give 7 as a sum.

     

    Possible combinations 

     

     

    N° of combinations

    sum of the two dices

     

     

     

     

     

     

     

    0

     

    1

    1+1

     

     

     

     

     

     

    1

     

    2

    1+2

    2+1

     

     

     

     

     

    2

     

    3

    1+3

    3+1

    2+2

     

     

     

     

    3

     

    4

    1+4

    4+1

    2+3

    3+2

     

     

     

    4

     

    5

    1+5

    5+1

    2+4

    4+2

    3+3

     

     

    5

     

    6

    1+6

    6+1

    2+5

    5+2

    3+4

    4+3

     

    6

     

    7

    2+6

    6+2

    3+5

    5+3

    4+4

     

     

    5

     

    8

    3+6

    6+3

    4+5

    5+4

     

     

     

    4

     

    9

    4+6

    6+4

    5+5

     

     

     

     

    3

     

    10

    5+6

    6+5

     

     

     

     

     

    2

     

    11

    6+6

     

     

     

     

     

     

    1

     

    12

  • The Drunk Bot is a robot that moves only forward and backward. It is guided by a mechanic arm that moves a shaker where there is a ball that can go in two tunnels: if it goes right the robot moves forward, if it goes left the robot moves backward. The Drunk Bot moves only going forward and backward on a lane; because it moves randomly, it is not predictable where we will find it after a while. But there is one thing that is predictable: if it moves 15 times, we cannot find it more then 15 steps far from the start.
     

  • Sweeper is the robot that we used at the "fiera"; it was built to move randomly in any direction; but it reaches a black line along its path it moves backward; it also has a pen that leaves a trace. We let it go on its own, for a while, on a sheet of paper with drawn a complicated path limited by black lines; after a while the robot covered the whole path. Thus when we leave this robot go, we know that:

    -          it moves randomly

    -         it is unpredictable where we will find it

    -        it is predictable that it will not get out of the black lines because it has been commanded to go backward when it finds a black line.

    -         it is predictable that if it has had enough time, it must have gone everywhere.

    -         It is possible that one moves around randomly and in the end he/she will have gone everywhere, like the sweeper..

  • Ciu ciuf brought a robot, "briciola" that moves on its own going randomly and succeeded cleaning a flat. Jeka said that if the robot had in its memory the map of the flat, perhaps it would take less time to clean it up; Teo said that the program would be very complicated and  the robot would need a different program for each flat. This is an example where randomness is convenient.

  • Sometimes it can be useful to choose a random strategy even if one is able to guide the robot. In the case of Rotty it is convenient  to go randomly when one has to hit many little spots one close to the other.
     
  • The funny thing is that it possible to write programs (predictable) that force robots to move randomly. We found out this thing by chance because Cleo said that all the robots move not randomly because they are driven by a program that has been written by someone in order to have the robot doing something specific.

    We discussed a lot on the issue: "Thus the Drunk Bot move randomly or not?"

    Cleo stated that it does not move randomly because it anyway executes the instructions of a program which is well defined and predictable.

    Sara stated that it moves randomly because it is guided by the ball whose movement is random

    We discussed a lot and Molly concluded that randomness is involved until the marble enters one of the two tunnels and from that moment everything is predictable.

    Jeka stated that this situation is like that of an elevator with the buttons messed up and without numbers: when we press a button, we choose randomly, but each button is linked to a specific floor and the elevator does not move randomly.
     

About this document

 This document has been firstly produced by Class2A as a collective class work, it may then evolve thanks to the contribute of Class2A, of its pupils, and of other pupils involved in the project. The evolution of this document may happen either directly in English or in Italian with relative translation. 
 

Translation notes

The first version of this document was produced in Italian by Classe2A, then translated by Michele. The pupils of Classe2A knew the document was to be translated.
 

  1. The original is "non a caso, certo, solito, abituale, sicuro". Here it is not clear if the italian "non a caso" is referred to "not randomly" or to "not by chance". Furthermore, they give more words, which are one synonym of the other. "certo" and "sicuro" are synonyms, and we translated them as "sure". "solito" and "abituale" are synonyms and we translated them as "usual".
  2. Pupils did not find a complete agreement on the issue if "predictable" is to be considered a contrary of "random", 6 of them voted yes, while 14 voted no.