The Grand Palais shares its colossal building with the Palais de la Decouverte (see page 75), and includes among its displays a hands-on exhibition of the sciences, with a planetarium as centerpiece.
The Grand Palais has a hands-on science exhibit.
Site selects itself in specific problem-for decisive testing, have to assume uniform system with regard to issue and so convenience sample acceptable; number of cases is usually one instance; comprehensive data for specific problem-for decisive testing, need more modeling, hypotheses, and targeting to know what to study; data analysis and collection concurrent and  data feed new collection, and emphasis on ruling out alternative causes; report describes instances, presents conclusions about cause, gives evidence