Oct. 8, 2008— -- Surveys based on a random sample of respondents are subject to sampling error – a calculation of how closely the results reflect the attitudes ...

A behind-the-scenes blog about research methods at Pew Research Center. For our latest findings, visit pewresearch.org. Every survey finding published by Pew Research ...

Key challenges of biopsy-based determination of prostate cancer aggressiveness include tumour heterogeneity, biopsy-sampling error, and variations in biopsy interpretation. The resulting uncertainty ...

The objective of a particle size analysis may be to obtain a bulk powder measurement to explore dusting tendency, filter blockage, or flowability, or to get the primary size of a particle system to ...