GIPS - dispersion measure internal vs. External

[bdeora]

Schweser example to LOS 49.s on gips, page 180, book1: on Manhattan Invst.
the example gives dispersion% as a column and explains the same as ” dispersion is measured as the std deviation of monthly composite returns”
the solution says this is a external measure of dispersion which is recommended and not the internal measure of dispersion which is required…
now i am really confused, the Schweser explains internal measure of dispersion as range of annual return, high/low return, interquartile range and std dev of equal/asset weighted annual return? so how come std dev is not internal measure?
or is it that if its annual std dev its internal measure and if its monthly returns then it’s external measure???
can someone throw some light
Dwight, getsetgo, tibwa, McLeod81 !!!

 

[heer]

internal measure is the dispersion of individual portfolios from the composite’s average return each year. In this particual case, they provide the external measure as it shows the composite’s dispersion from the average return over the years.

 

[bdeora]

Heer,
i am not sure i understand your explanation, some more clarity ?

 

[heer]

measure of internal dispersion is the individual portfolio’s dispersion around the average composite return for each year. Right?
The case actually provides the indivudial composites dispersion for a given year around the average composite return for all years.
Sorry may be I am unable to explain clearly.