Sample size
To determine the required sample size at 95% confidence level and 80% test power, assuming that the effect of Pimpinella Anisum on human milk volume in the intervention group should be 25 unit (d = 25) for the effect to be considered statistically significant compared with the control group, the sample size in each group was estimated to be at least 38 people using the sample size formula. The total number of participants in this study was therefore 145 individuals.Based on the study by Turkyılmaz et al., (2011) the standard deviation of milk volume was estimated to be 53.5 and 12.9 in the intervention and control groups, respectively. Also, with regards to the weight of neonate, the sample size of 15 people in each group was determined [