A further 932 were recruited from the public to act as a control group for comparison. |
Direct evaluation cannot be done because very few ganzfeld studies have included a control group. |
As healthcare providers, we often wonder whether it is ethical to use a control group or not. |
Collection of the control group was essential for the evaluation of seropositivity among the general female population. |
Results showed a significant improvement in the iron, iodine and vitamin A status of these children compared to a control group. |
Researchers tested their SARS vaccine on four African green monkeys, with another four in the control group. |