More recent data on player motivations is available here.

A model of player motivations based on empirical data was first attempted in the Facets study. While it was clear that different players derived satisfaction in very different ways (for example, gender differences), it wasn't clear what those different elements were or how they should be grouped, assessed or related to other aspects of game-play.

A list of possible reasons players might be motivated was generated based on existing models, such as Bartle's Types, or anecdotal information from previous surveys. Respondents then rated their agreement to each of these statements. A factor analysis was then performed on this data to separate the statements into clusters where items within each cluster were as highly correlated as possible while clusters themselves were as uncorrelated as possible.

This methodology achieved three goals:

1) Ensure that components of each motivation are indeed related.
2) Ensure that different motivations are indeed different.
3) Provide a way to assess these motivations.