A sample of 364 urban African American males were approach for a study recruitment. Of the 364 participants 136 (37%) completed a self administered baseline survey and were further randomized to a condom promotion program. The remaining 228 (63%) did not participate in the baseline survey due to not wanting to participate or intelligibility.

What type of sampling technique was used and was it probability or non probability technique?

Probability sampling include- simple random sampling, Systematic sampling, cluster sampling or stratified sampling

Non-probability sampling include- convenience sampling, voluntary response sampling, purposive sampling or snowball sampling