Data Collection

Data Collection

1. Sampling strategy

   • Randomized
     • SRS
       • every individual and group has equal chance of representation
     • Randomized
       • Stratified
         • some of every group
       • Systematic
         • Start x and then every n
       • Multi-staged
         • SRS of SRS
       • Cluster
         • randomly choose all of one group
   • Non-Randomized
     • Conveniance
     • voluntary response
       • Sample survey

2. Study design

   • Observational
     • Sample Survey
       • Cross-sectional study, response bias, undercoverage
       • Voluntary
       • randomly selected
     • Cohort
       • Prospective, longitudinal study
     • Case-Control
       • Retrospective, comparison of two samples
   • Experimental
     • Completely Randomized
       • Matched pairs/Repeated measures
         • if you CAN you pair the data
     • Blocked
       • Grouped before assigning treatments