An experimental researcher selects students who had low scores on a math pre-test and high scores on a math post-test to participate in a study examining the influence of a new math curriculum in an elementary school grade. What potential threat to validity exists in the experiment?

History

Explanation:

The history of the students in relation to their mathematical skills is a potential threat to validity of the experiment.

depends on what they need

the aksumite empire was an ancient kingdom located in what is now northern ethiopia from the period of 100 ad to 940 ad. its capital was the city of aksum. the kingdom established itself as one of the 4 great powers at its time, along with persia, rome, and china.

the kingdom was rich in goods like gold, iron, and salt. it established strong commercial ties with the regions governed by rome, egypt, and persia (arabia). aksum was a key location in this commercial network. trade was also facilitated with the introduction of the aksumite currency.