Does essentially unchanged mean exactly same?

[compiler]

I got a reply about a comparison of two X-rays, essentially unchanged. Does essentially unchanged mean exactly same or 100% same? If no, can you explain how much percentage of the same approximately such as 95%, 99% etc. in your mind if you hear "essentially unchanged" between the comparison of two things? Thank you for your answer.

 

[GoesStation]

It doesn't mean "exactly the​ same". It means "no clinically-significant differences". I don't think you can express this clinical impression as a percentage.

 

[Skrej]

They're not 100% the same, but the differences are so small as to be unimportant. The changes shown between the two X-rays aren't medically significant.

I wouldn't suggest trying to put a number on the amount of difference, because people will differ in their opinion of how much 'essentially' unchanged really means.

It's also going to depend on the situation, and what kind of room there is for tolerances. For something very precise, a small amount might be still be significant. Another situation might require really substantial differences to be significant.

 

[Eckaslike]

"Unchanged" means the two items under comparison are exactly the same. "Essentially unchanged" means that they are virtually identical, but not exactly the same. However, the difference between them is negligible.

"Essentially unchanged" is a general term and, in my experience, does not fit with an exact percentage score. That being said, the comparison must be reasonably close to the 100% mark in order for the word "essentially" to have been used. I wouldn't think in terms of a percentage, but would find out what had changed in order for you to determine whether or not you agree that the difference between the two x-rays is negligible.

[Cross-posted]

 

[GoesStation]

The responses from GoesStation, Skrej and Eckaslike were essentially the same.

Yes, but not 100%. Not even 95%, to be honest.

 

[Tdol]

As low as 94.5%?