2.1. Study design

A cross-sectional biosafety survey was carried out from July 2014 to July 2015. The target population included graduate students, academics, laboratory technologists, research officers, and veterinary clinicians working in veterinary research facilities across the six geopolitical zones of Nigeria. The sample size formula (n = Z² p (1 – p) / d²) for field study according to Thrusfield [29], where n is the computed sample size, Z is the degree of confidence (1.96 in this study), p is the expected proportion, and d is the desired absolute precision at the 95% confidence level (10% in this study), was used to obtain the target sample size. For this study, as we had no prior data regarding the proportion of researchers in veterinary facilities having a good laboratory knowledge score (defined as greater than one standard deviation above the mean), therefore, we set p at 50%. This gave a minimum sample size (n) of 96 respondents. To increase precision, 160 questionnaires were administered to respondents through a snowballing technique. This technique is a chain referral process in which respondents in veterinary facilities from the six geopolitical zones were asked to recommend other researchers until the desired sample size is met.