What was the result of john brown's attack on harper's ferry?

An education expert is researching teaching methods and wishes to interview teachers from a particular school district. she randomly selects ten schools from the district and interviews all of the teachers at the selected schools. which type of sample did she use in this study? a)systematic sample b)probability sample c)stratified sample d)cluster sample

What occured in preparations of war

Aresearcher is studying women recently admitted to a state prison. all potential subjects must have children under the age of five. research subjects will be given a basket of toys to use at their children’s first visit that the children can then take home. in assessing this proposal, the irb needs to determine that the toys are: age appropriate.not an excessive incentive.educational.of high quality.