Philadelphia study

[1][2] To test his hypothesis, Labov identified socially and ethnically central groups by gathering information on five Philadelphia neighborhoods through census data and initial surveys.

The goals of these interviews were to gather social data on the residents, their block, and the neighborhood and analyze linguistic variants without facing the problem of the observer's paradox.

With the social information gathered from the interviews, he discovered that it is not the education or occupation factors that drove the middle class to spur linguistic change.

To eliminate bias and errors due to other social factors such as age, Labov created the Philadelphia telephone study to corroborate the curvilinear hypothesis.

[3] The telephone survey was done through random sampling of Philadelphia phone numbers, and therefore eliminated the biases that occur with selection of neighborhoods and interviewees.