In the comparative study of the cost of mass transit, analysts at Mercer selected the most convenient and popular means of transportation between bus and subway in a given city and gauged the price based upon a ride in the city center for one adult, according to the Mercer analysis team.

FORBES: In Pictures: World's Most Expensive Commutes - 2. Tokyo

"The Impact of Urbanization on Biosphere Reserves: A Comparative Study of Protected and Non-Protected Coastal Areas".

UNESCO: Informes de las Becas MAB - (MAB Young Scientists Awards)

As the study points out, numerous comparative studies of organic and conventional yields have already been conducted with conflicting results.

CNN: Study: Organic yields 25% lower than conventional farming

Originally the San Francisco researchers had hoped to do a comparative study of different agencies' programmes, but for this project only Compassion chose to take part.

BBC: Is child sponsorship ethical?

For example, a comparative study of results before and after the defeat by Brazil could provide experts with incontrovertible proof of whether there is a "feel-good" factor involved in exam performance.

BBC: A game of two halves

They could not handle the amount of data that he wanted to analyze for his dissertation, which was part of a comparative study based on surveys in seven nations.

FORBES: The First Data Scientist on the Evolution of Data Science and the Ever-Changing American Voter

Furthermore, the study will explore the contents of textbooks in several regions of the world in order to analyse in a comparative perspective the different representations of the Holocaust and how it is actually taught to pupils and students.

UNESCO: Education