This problem offers an engaging context for planning and carrying out a data-handling activity. Many problems that students meet are "tidy"; this activity prepares students for the messy nature of real-world data-handling. Students will need to make decisions about the data they need, and to search for that data.
Show the medal table from the 2012 Olympics.
When groups present their findings, encourage the other groups to offer constructive feedback on the decisions they chose to make, the evidence they chose to include in their analysis, and the parts of the presentation they found most convincing. One way to do this is for each group to make a short presentation with time for comments and questions afterwards. Alternatively, groups could prepare a poster presentation and then time could be allowed for everyone to go round and look at each poster, writing feedback on post-it notes.
Does the Olympic table rank countries fairly?
Some simple and quantifiable criteria that students could use in their analysis could be population size and wealth of the nation. It may be worth finding out some of this data in advance in order to guide the students' searches.
Students could use data from previous Olympics to see the extent to which their criteria give a constant list of most sporty nations over time.