"Conservative estimation" means making a cautious and safe guess or prediction, where the actual outcome is likely to be even better or more favorable than what is estimated. Full definition
As such, while I take the failure to make such a distinction to be important, I do not consider it to be a major failing — particularly if it results in a more conservative estimation of the strength of the consensus that exists regarding the science itself. (realclimate.org)
In the most conservative estimation approach, a good principal (one in the top 16 percent of principal effectiveness) compared to an average principal annually gets the equivalent to an extra two months of learning out of students. (educationnext.org)
$ 1.5 million is therefore a conservative estimation of the cost to manufacture each of the park's robots. (cnbc.com)