Regarding my study design with pre-test-post-test for the same subjects design, samples would need 27 samples to see average change in knowledge (CDM knowledge) from pre-test to post-test with the alpha 0.05, power 0.08 and medium effect size of 0.5. However, Researcher will recruit 34 participants to cover 20% of drop out for each group. Altogether 68 participants will be needed.