$1.$ How could you ensure valid and reliable primary data?

$2.$ How could you ensure valid and reliable secondary data?

$3.$ Which is more reliable, primary or secondary data? Why?

$4.$ Differentiate: evaluation research, research and development, action research.

$5.$ Explain: The type of data to be collected determines the type of research to be conducted.

$6.$ Explain: data triangulation, data screening, data saturation.