1.   But at this point, no valid comparison can be made between their clocks, for they are separated.

2.   There is not enough data for a valid comparison to be made.

3.   Valid comparisons are difficult to draw from existing publications, particularly between species.

4.   There is no valid comparison with drugs.

5.   And yet people with the proper background and level heads say it just might be a valid comparison.

6.   Because enterprise value accounts for net debt, Brody believes it makes for a more valid comparison among stocks and indexes than, say, price to cash flow.

7.   A more valid comparison might be performance against bowl teams.

8.   Experts agree that valid comparisons of schools, districts or states must adjust for differences in student background.

9.   It has been too long since a major bout was on free TV to allow a valid comparison in the age of cable.