Instead of creating a concrete definition of a street gangs, research has come to show that static definitions are problematic as they are either too broad increasing the issue, or too narrow ignoring the issues in the community. Thus, a typology will allow communities to evaluate the issues within their community, and come to develop local programs to address specific behaviours of their members before these individuals come into contact with the criminal justice system.

Definitions are useful in allowing researchers, policy makers, and theorists to understand youth gangs as a whole. However, it is also important to note that agencies in rural and urban settings that work with youth gang members and youth at-risk to gang membership need to create a definition that is unique to its youth gang situation.

Due to the differing social histories between locales, some youth have been marginalized within their neighbourhoods because of their race and economic status. The social history of the neighbourhood influences whether a particular youth is more at-risk to enter a gang lifestyle because of limited opportunities.

A second reason for agencies to create a definition is because communities may differ in their interpretation of what constitutes a gang. National studies can be misleading if communities do not share an understanding of what defines youth gangs, or the criteria used to define a gang.

By understanding how researchers, theorists, and policy makers narrow or broaden the criteria used to assess youth gangs, we can see how politicking becomes a major factor in designing and assessing programs designed for youth gangs. Therefore to understand and assess the youth gang phenomenon, researchers, theorists and policy-makers must work together to derive a set of criteria upon which they can come to agree to assess youth gang activities and behaviours.

An example of a youth gang typology can be found below.