What is a "security variable"?

Question

I just read an article about different ranking algorithms . One thing that I'm a bit confused about is stambbleupon algoritm:

(Original post stumbler / # domain) + ((% stumbler visitor / # domain) + organic bonus - unfriendly) - (% seductive audience + organic bonus) + N

N is a "security variable", so the intended algorithm is flexible. This represents a random number.

Can someone explain me purpose N? I do not understand how to make the algorithm more flexible.

Answer 1

. - , , , , .

. , , , , , . .

stumbleupon :

, , . , .. ,

Answer 2

N, , , , ( N ). , , , , , , , ( , ). .

.