The is a method in which neither the research participants nor the researchers know whether the participants are getting the treatment or a placebo.

The double-blind study is a method in which neither the research participants nor the researchers know whether the participants are getting the treatment or a placebo. Is a tool of the scientific method used to prevent research results can be influenced by the placebo effect or observer bias.

delete this messag epls it wont let me out this exit2

muslims have taken his goods and products to different parts of asia an indonesia. sometimes just traveled and trade, but in other occasions, stayed in the place and made a living.

trade was the key for muslims economies to prosper. their commerce routes reached far places like malaysia and java in the 11th century.

another important factor for prosperity was that muslim states served as the middle point for european traders.

they used to travel by land but sailing the seas -the indian ocean- really increase the exportation of products.