posted on the ibge website, the paper em busca da redefinição de favelas e assemelhados  (searching for a new definition of favelas and similar) by valéria grace costa is a study on the redefining of the word 'favela' and can be read on this link.

because rio's favelas can differ significantly in terms of construction types and sizes, access to services, and overall dimensions, the ibge currently places more emphasis on the legal rather than physical status of these agglomerations.

our own research found that most residents in rio de janeiro would consider a 'favela' any area or neighborhood in the city that would match 4 out of 6 of the following parameters: