A strength of this method of experimenting is that it is scientific. This is because the variables of the experiment are strictly controlled during a laboratory experiment, which further means that cause and effect can be established (that the independent variable has had a direct effect on the dependent variable) - an important part of science.
However, a weakness would be that laboratory experiments lack ecological validity, because they take place in a laboratory and not in a realistic real life situation. This affects the validity of the experiment, and this means that the results of the experiment may not reflect what would happen in real life.