LISA is an acronym standing for 'Local Indicator of Spatial Autocorrelation,' a family of statistical methods first introducted by the French geostatistician Luc Anselin in 1995. The most commonly used variant is the local Moran coefficient, which is defined as:

Ii=(zi/m2)*sumj(wij*zj)

where zk=xk-avg(x) and m2=sumk(z2k/n), and is computed for each locality i and its neighbouring localities j. The wij parameter allows the researcher to define the spatial extent of the analysis.

This coefficient can be calculated for each locality in a data series, and the significance of each value of the coefficient can be determined by permutation.

What does all of this mean? By way of a LISA analysis, a researcher in possession of a spatial data series can identify hot-spots as those localities where strong spatial processes are underway.

she's got hands that have touched the world and everyone within
she's got ways to make herself sickly, sickly thin
she's got lips that lie but almost try to bless
she's not there when you try to make her feel a little less

like dirt.
she's hurt.
got nothing left inside,
nothing but her pride
her mouth is gaping wide
she wants to take you in. she can suck you in.
she will drag you in, make her feel better about herself.

her skin's so bruised from the tangled fingers in her hair
her skin's so blue, not just from the lack of air
her eyes bleed when she cries those tears from an empty heart
but she needs to have someone else to tear her all apart

like dirt.
she's hurt.
got nothing left to say,
set within her ways
she kneels to them and prays
she wants to show you how she's better off than now.
she will tell you how she feels better about herself.

011200

Log in or registerto write something here or to contact authors.