A research team led by Prof. PAN Ding, Associate Professor from the Departments of Physics and Chemistry, and Dr. LI Shuo-Hui, Research Assistant Professor from the Department of Physics at the Hong ...
primary - information that you collect yourself, eg tallies, measurements and photographs secondary - information that someone else has previously collected and made available, eg on the internet The ...
Stratified sampling is used to select a sample that is representative of different groups. If the groups are of different sizes, the number of items selected from each group will be proportional to ...