a group of randomly selected subjects for a study that matches the population on important characteristics such as age, gender, etc., is called .

if it is a supervisor that collects all the handmade products the word is you but if it goes straight to the machine made activity there isn't any word unless there is robot programmed to say you.

this null effect is caused by a weak manipulation and ineffective internal validity. in a scientific study, as the one dr. morimoto is trying to perfom, internal validity refers to the confidence placed in the cause-effect relationship and to how well an experiment is done and able to eliminate confounding variables.        

one way archaeology us understand the past is through the material objects it finds, allowing us to know what was being used, and when. for example a dig recently found a flute, believed to be the oldest musical instrument found to date.

i hope this