The subsidy was available for three years, but only to people who began working full-time within 12 months of random assignment.
But with random assignment, both treatment group and control group get a fair share of all such misleading factors; they balance out.
Now, so we have the idea of a random assignment.
They desire a generally better situation and refuse random assignments to remote regions of the country.
In an experiment with random assignment, study units have the same chance of being assigned to a given treatment condition.
As such, random assignment ensures that both the experimental and control groups are equivalent.
If no solution has been found after a given number of changes, a new random assignment is selected.
However, since most programs cannot use random assignment, causation cannot be determined.
In typical scientific experiments, treatment and control groups are selected through random assignment.
A value of zero indicates no improvement over a random assignment.