Yes. A short term test can be useful in giving an indication of the radon levels in a home.  For example if work has been carried out to reduce high radon levels in a home, a short term test may be used to give an early indication as to whether the work has been successful.  However, a three month test will still be needed to determine if the radon levels are below the national Reference Level.  Short term radon measurements of a few days are not recommended as a basis for deciding whether or not you have a radon problem.