In research described in the text, niedenthal and others (2012) related pacifier use during infancy to impaired socioemotional development later on. however, the researchers stated that "the studies . . do not allow causal conclusions, as the children were not randomly assigned to pacifier use." based on this information, one can infer that the studies were rather than

Based on this information, one can infer that the studies were correlational, rather than experimental.

Correlational research simply defines if there is a relationship between two variables (covariation). This study greatly differs with experimental studies. Experimental studies is a method where treatments( independent variable)  are applied and the effects(dependent variable) are observed and recorded.

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.