1. Identify key information sources
{"Image DocumentName": "1. Identify key information sources", "Image ImageDescription": "RESEARCH. Randomisation is a sampling technique characterised as having no predetermined pattern or plan for selecting sample documents. Stratification is a systematic sampling technique that attempts to reduce the variance of estimates by equally dispersing the sample selection within a given population - that is, choosing documents or records by formula.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}