
It was sparsely sourced,
but I think the science is VALID.
The Big Bang Theory Season 1, Episode 3

That's actually a VALID example.
The Big Bang Theory Season 8, Episode 21

That was a VALID hypo...?
What is happening to you?
The Big Bang Theory Season 1, Episode 1

You know, if this experiment is going to
be VALID, I suggest a neutral environment.
The Big Bang Theory Season 10, Episode 4

...where a tray of flatware
on a couch is VALID?
The Big Bang Theory Season 1, Episode 2