Sampling and Validity

Sampling & Validity

At ROI, we believe that statistics is as much art as science. This is most evident when drawing for our clients, samples from larger populations of target audiences or stakeholders, or when determining the best research design to elicit the required informational needs. In either of these steps, we always strive to work in consideration of real-world constraints including budgetary, legal, human capital, socio-political and temporal factors. We generate the best information for our clients to make informed decisions. Through the valuable insight offered by our elite team of statisticians, we are best at enabling our clients to bridge through various research constrains. We have a team of analysts and statisticians who are creative and robust when it comes to developing the most rigorous sample and study design for clients. We e provide our clients with detailed, customised reports on optimal sampling, design, methodology, and measurement, including professional commentary and recommendations in an array of aspects. This includes but not limited to;

  • Sampling frame development
  • Stratified random sampling
  • Random sampling
  • Weighted samples
  • Nonprobability sampling
  • Snowball and convenience sampling
  • Purposive sampling
  • Sample validity
  • Non–response bias
  • Statistical power testing
  • Post hoc power analysis
  • Quasi-experimental research design
  • Non-experimental design
  • Internal validity
  • External validity
  • Statistical conclusion validity
  • Theoretical validity
  • Measurement validity
  • Measurement reliability
  • Convergent validity Divergent validity
  • Inter-item validity

We provide our clients with a range of advisory services and help ensure they have an in-depth understanding of their data. Ultimately our clients can make sound and reliable decisions. Even for organisations with in-house data expertise, it is not always easy for them to get their teams to successfully undertake statistical tasks required to turn data into informative, actionable and reliable insights. At ROI, we support our clients in selecting the most appropriate analytical techniques including statistical tests and also advice on the best ways to present their results.