Property variation between different samples makes the obtained data difficult to achieve self-consistency.
"The number of U.S. workers filing for initial jobless benefits stayed near a six-year low last week, though continued reporting irregularities make the data difficult to read.
These issues make such data difficult to access, to assemble and to analyze over large spatial and temporal scales9,21,22.
Also, the presence of slow or expensive communications links in the system can make maintaining closely synchronized copies of data difficult or uneconomical.
The most common models used today rely heavily upon empirical information obtainable only from pilot size experiments and this makes "a priori" design from small scale data difficult.
But there could be deeper issues afoot if you find yourself awake at 4am every morning worrying about data, difficult parents, or what colour backing paper to use for a display.
Despite this, more than 80,000 animals could be killed to test just the first 67 chemicals — even though these animal tests, developed in the '30s and '40s, are so inexact they will yield data difficult to interpret.
There is enough of a trend, Mr Briscoe says, for the Bank to stop raising rates.However, one-off factors make the data difficult to interpret.
A separate report showed the number of Americans filing new claims for unemployment benefits fell last week, although Hurricane Sandy made the data difficult to interpret.
Various combinations of anesthetics and ambient conditions have been used by different laboratories making comparisons problematic and differences in data difficult to reconcile.
The shift in sensor signal measured by identical gas sensor array system (commonly called an electronic nose) makes the analysis of merged measurement data difficult.
