An educational psychologist wanted to know if second grade students were more accurate at solving math problems when the teacher presented the problem in a nonverbal picture form compared to a verbal story form. Students were randomly assigned to conditions and the results revealed more correct answers in the nonverbal condition. What type of manipulation did the researcher use?

The ideas of hammond are most clearly an example of which of the following mid-19th century developments? (5 points) the increasingly liberal nature of slavery after the south enforced stronger slave codes the growing use by northern antislavery activists of moral arguments the increasing number of freed slaves in southern states as a result of gradual emancipation laws the growing tendency of southern slaveholders to use the paternal ethos to justify slavery