Identical random samples by different students in different classes in different years.

If the samples were generated with a pseudo-random method, identical samples are possible because pseudo-random numbers come from an algorithm, not true randomness.

Two common reasons are:

1. The same seed was used If separate Random objects are created with the same seed, they generate the same sequence of numbers.
2. Separate generators were created in close succession In .NET Framework, the parameterless Random() constructor derives its default seed from the system clock. If two generators are created close together, they can receive the same seed and therefore produce identical sequences.

Relevant details from the platform behavior:

• Random represents a pseudo-random number generator.
• Using the same seed for separate Random objects produces the same series of random numbers.
• In .NET Framework, Random() can create identical sequences when objects are instantiated close together because the default seed comes from the system clock.
• In .NET Core, that specific limitation does not apply in the same way, because the default seed is produced by a thread-static pseudo-random number generator.

So, two unrelated students can get identical “random” samples if the software used a pseudo-random generator with the same starting seed, especially if the generator was initialized the same way each time.

• Random Class
• Random Constructors