In all our discussions, a principal component series is weighted combination of up to 70 individual tree ring series. (climateaudit.org)
The error in calculations are based on weighting of two or three questionable tree ring series which show a rise after 1850 by a factor of several hundred in comparison with all the others. (climateaudit.org)
That paper excluded 77 of the 95 pre-1500 tree ring series used in MBH98, and WA2007 showed that the results of MBH98 could be replicated very closely using all the data. (skepticalscience.com)