Recording all instances of an event for a particular time period (such as how many times an older brother strikes his younger brother) without the subjects' awareness is an example of:

I believe the answer is: naturalistic observation

Naturalistic observation is being done without any form of variable manipulation from the researchers. The purpose of such observation is to make the result of the study represent the actual condition as close as possible. Usually only applicable for qualitative data.

the federal government of the united states was established by the constitution. us is a presidential republic. the president is head of state, head of government and of a two party legislative and electoral system. the supreme court balances the powers of the federal and the state government. yhe executive branch is headed by the oresident. there are two chambers of congress, the senate and the house of representatives. judicial power is exercised by the judicial branch (or judiciary), comprised of the supreme court and lower federal courts. the judiciary's function is to interpret the   constitution as well as the federal laws and regulations.