

Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
The concepts of means, standard deviations, covariances, and pearson correlation in statistics. It covers the computation of these statistics, including the use of user-specified treatments for missing values. The document also discusses the significance level of pearson correlation and provides references.
Typology: Study notes
1 / 2
This page cannot be seen from the preview
Don't miss anything!


1
The user-specified treatment for missing values is used for computation of all statistics except, under certain conditions, the means and standard deviations.
The following notation is used throughout this chapter unless otherwise specified:
N (^) Number of cases X (^) kl Value of the variable^ k^ for case^ l wl Weight for case^ l Wk Sum of weights of cases used in computation of statistics for variable^ k
Wkj Sum of weights of cases used in computation of statistics for variables^ k^ and^ j
k
l kl l
N
k
k l l
N kl k^ k^ k
=
=
1
2 1
Note: If no treatment for missing values is specified (default is pairwise), means and standard deviations are computed based on all nonmissing values for each variable. If missing values are to be included or listwise is chosen, that option is used for means and standard deviations as well.
2
The cross-product deviation for variables i and j is
Cij w Xl il X (^) jl w X w X W l
N l il l
N l jl l
N = โ ij
%
'
& &
(
0
) )
%
'
& &
(
0
) ) = = =
โ โ โ 1 1 1
The covariance is
ij W
ij ij
r
ij
ij ii jj
The significance level for rij is based on
t r
r
ij
ij ij
which, under the null hypothesis, is distributed as a t with Wij โ 2 degrees of freedom. By default, the significance level is two-tailed.
References
Blalock, H. M. 1972. Social statistics. New York: McGraw-Hill.