Layla and Other Assorted Love Songs peaked at #16 on Billboard' s Pop Albums chart and was certified gold by the RIAA. The album again made the Billboard 200 in 1972, 1974 and in 1977. In 2011, it charted in Britain, peaking at number 68. In 2000, the album was inducted into the Grammy Hall of Fame. In 2003, television network VH1 named Layla and Other Assorted Love Songs the 89th-greatest album of all time, and Rolling Stone ranked it number 117 on its list of  The 500 Greatest Albums of All Time .
Observation consists of receiving knowledge of the outside world through our senses, or recording information using scientific tools and instruments. Any data recorded during an experiment can be called an observation. A scientific process or scientific method requires observations of nature and formulating and testing the hypothesis.
Now to one of the main objectives for this section. Two other very common sources of data are observational studies and designed experiments. We're going to take some time here to describe them and distinguish between them-you'll be expected to be able to do the same in homework and on your first exam. The easiest examples of observational studies are surveys.