Generating correlated data for simulation

I have a set of values in a 1D array of size N. How to generate another array of slightly greater or lesser size with values that are approximately equal? One can assume that the first array was (subjectively) obtained by a person A from some process and the second by person B from the same process; I have to check how closely they agree. Before I move on with the experiment, I wish to fiddle with the possible cases.

Answer 1

[Jeff Miller]

One option is to create the second array by adding a random number to each element of the first array. For example

sigma = 1; % increase or decrease to control the size of Array1/2 differences
Array2 = Array1 + normrnd(size(Array1))*sigma;