How did new england's textile industry affect both children and women? allowed them to earn a living wage until the age of 25 gave them opportunities not available on family farms permitted them to complete their schooling provided long-term employment even after marriage

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.