The american psychological association has established a set of ethical principles for research with human participants. the experimenter is usually required to give participants a complete description of the experiment before they are allowed to participate. this illustrates the principle of

This illustrates the principle of informed consent.

In all research experiments the experimenter has to have complete consent from all participants involved. They are required to give them a document to read through explaining the experiment, any risks involved, confirmation of data confidentiality etc. and the participant will sign the document if they agree. This is called informed consent. It protects the experimenter and the participant.

answer; /// (culture);

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.