Educational psychologists investigate the impact of different types of instruction on learning. In one study, researchers taught a math lesson to 9th-graders using the "Inventing to Prepare for Learning (IPL)" instructional cycle. A second group of students received traditional "tell and practice" instruction. After the lessons, both groups studied a worked example of a math problem on their own. Then they took a test that included problems like the worked example. The journal Cognition and Instruction published the results in 2004. Pick the best description of this study: Group of answer choices an observational study to make an estimate or a claim about a population an observational study of an association between two variables. an experiment to establish a cause-and-effect relationship between two variables

An observational study of an association between two variables.

Explanation:

In the given scenario, it is an observational study of an association between two variables. The variables being  :

Observational study observes individuals and records variables but doesn't attempt to influence the response (does not impose a treatment). It allows the researcher to directly observed the behavior of inteest rather than rely on the subject's self-descriptions (Survey) thus allowing the researcher to study the subject in its natural environment, thus removing the potentiallybased effect of the unnatural laboratory setting on the subject's performance.

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.