Validity and reliability--What's it all about?  Part 1. Validity in quantitative studies.
Twycross
Alison
A
Glasgow Caledonian University, Yorkhill, Scotland.
Shields
Linda
L
D003625:Data Collection / Q000592:standards*; D006801:Humans; D015399:Nursing Research / Q000592:standards*; D015203:Reproducibility of Results; D012107:Research Design / Q000592:standards*