Answer:
Observational
Step-by-step explanation:
When differentiating between observational and experimental research designs, the simple idea is to focus on the intervention of the researchers and that whether the participants have been offered any treatment or not. Here, in the given case, children are divided into groups and one has been shown a video with bullying while other group has not seen any such video. And then change in their behavior is 'observed' and are questioned about their attitudes. Hence, this is an observational study. If they were given some medicine, intervention or treatment then this would have been an experimental research.