The biorhythm theory is often presented as having scientific validity.

It was based on medical and genetics theories which are now of questionable scientific validity.

The quality and scientific validity of articles published in the Journal has been criticized by others.

It is in fact a question about the scientific validity of the enterprise.

Some ideas are found, or intended, to have no scientific validity at all.

The whole thing's a fraud, with no scientific validity whatsoever.

Such tests lack true scientific validity, but they provide the best indicators yet developed.

For people who sit in front of computer monitors all day, the old joke about being allergic to work may have some scientific validity.

However, it suffers from a lack of scientific validity in cases where other potential changes can affect the data.

There is absolutely no scientific validity to this statement.