Without the additional context, my first guess would be that is refers to an inference based on a statistical (or graphic?) representation of the data, but since they are also weighing it against other measurements, I would agree with the above. The wikipedia article on statistical inference:
http://en.wikipedia.org/wiki/Statistical_inference
says that the conclusion drawn is a stastical proposition, among which they also list "confidence interval" which usually helps determine a "confidence level." You may also want to scroll down to "Frequentist inference," which is based on sampling, and also has "confidence interval" as a subtype. Wikipedia also describes "confidence interval" (on its on page) as "In statistics, a confidence interval (CI) is a particular kind of interval estimate of a population parameter."
(
http://en.wikipedia.org/wiki/Confidence_interval) Anyway, I hope this helps.
The translation workplace 
