Results from a research study suggest that a stop-smoking program is very successful. however, the participants who volunteered for the study were all highly motivated to quit smoking and the researcher is concerned that the same results may not be obtained for smokers who are not as motivated. this study has a problem with

The correct answer is The study has a problem with the External validity

Explanation:

External validity in research terms is the validity the research has in the outside world or in the applied social reality of the field of study, it is the extent in which the results and conclusions of the study can be applied and generalized to ohter external factors, therefore in this case, when the researchers did the experiment only with motivated volunteers did not take into account that people outside may not have the same motivation, therefore the results may not be the same in the external social reality and thus having problems with the external validity.

well, paralell is parallel. i am providing links to .

hope this !

a series circuit is one with all the loads in a row. there is only one path for the electricity to flow. if this circuit was a string of light bulbs, and one blew out, the remaining bulbs would turn off.

unlike in series circuits, a charge in a parallel circuit encounters a single voltage drop during its path through the external circuit. the current through a given branch can be predicted using the ohm's law equation and the voltage drop across the resistor and the resistance of the resistor.

a parallel circuit has certain characteristics and basic rules: a parallel circuit has two or more paths for current to flow through. voltage is the same across each component of the parallel circuit.