Accuracy is the proportion of all articles that are correctly categorized by the search strategy
Source : http://hiru.mcmaster.ca/hiru/HIRU_Hedges_home.aspx
physician adj5 relationship retrieves records that contain the words physician and relationship within five words of each other in either direction.
E.g. physician patient relationship, patient physician relationship, relationship of the physician to the patient, and so on.
Source: OVID help, available from: http://www.ovid.com /site/help/documentation/ospb/en/syntax.htm#operators
The AND operator lets you retrieve only those records that include all of your search terms. For example, the search “blood pressure AND stroke” retrieves only those records that contain both terms “blood pressure” and “stroke” together in the same record. Results exclude records that do not contain both terms.
Source : OVID help. Available form: http://www.ovid.com/site/help/documentation/ospb/en/syntax.htm#operators
Image source : http://en.wikipedia.org/wiki/File:LogicGates.svg
Source: Guyatt G, Evidence-Based Medicine Working Group. Users' guides to the medical literature : a manual for evidence-based clinical practice. 2nd ed. New York: McGraw-Hill Medical; 2008.