A developmentalist is studying the relationship between parental physical punishment (e. g., hitting, spanking) and first graders' aggression. Her plan is to individually watch each parent interact with a child at home, and then observe that child's behavior at school. Name the type of measurement strategy this researcher is using, and spell out its advantages and disadvantages.

As we see those go to grave, we think of those who stand tall in the battle wave. as we see those who were slave, we think of those who thought their cause was brave. as we see those fight, we think of those who were right. as we see the battle began, we think of how it never ends. as we see those with pride, we think of those who died. what shall i change in this poem? shall i just keep it or add another line?