Hi,
I'm trying to get standard errors for some of the variables in my data
frame. One of the questions on my survey is whether faculty coordinate
across curriculum to include Arts Education as subject matter. All the
responses are coded in zeros and ones obviously. For some of the other
variables I have a 2 for those that responded with "Don't Know".
I'm getting NA for mean and standard deviations from svymean. Am I doing
something wrong of can the survey package not handle this type of data?
Here's my code.
> survey <- svydesign(id=~1, data=General, strata=~Grade.Level)
Warning message:
In svydesign.default(id = ~1, data = General, strata = ~Grade.Level) :
No weights or probabilities supplied, assuming equal probability
> summary(survey)
Stratified Independent Sampling design (with replacement)
svydesign(id = ~1, data = General, strata = ~Grade.Level)
Probabilities:
Min. 1st Qu. Median Mean 3rd Qu. Max.
1 1 1 1 1 1
Stratum Sizes:
Elementary High Middle
obs 312 236 156
design.PSU 312 236 156
actual.PSU 312 236 156
Data variables:
[1] "Grade.Level" "Curriculum"
[3] "Field.Trips" "Residencies"
[5] "PTA.Support" "Community.Open.Performances"
[7] "Visual.Arts.Attendance" "Literary.Arts.Attendance"
[9] "Arts.Organization.Membership" "Arts.Essential"
> svymean(~Curriculum, survey)
mean SE
Curriculum NA NA
???
PJ
Survey Package with Binary Data (no Standard Errors reported)
2 messages · Paul Jones, Thomas Lumley
3 days later
On Fri, 3 Apr 2009, Paul Jones wrote:
Hi, I'm trying to get standard errors for some of the variables in my data frame. One of the questions on my survey is whether faculty coordinate across curriculum to include Arts Education as subject matter. All the responses are coded in zeros and ones obviously. For some of the other variables I have a 2 for those that responded with "Don't Know". I'm getting NA for mean and standard deviations from svymean. Am I doing something wrong of can the survey package not handle this type of data?
Are you sure you don't have any NA values in the data? If you do, the na.rm=TRUE option to svymean() will fix your problem. If you don't, something mysterious is happening. You could try svytable(~Curriculum, survey), which will give a tabulation and might show up what is strange about your data. As a separate issue, you might want to look at svyciprop() if some of your proportions are close to 0 or 1, to get better confidence intervals.
Here's my code.
Nothing obviously wrong with it. -thomas
survey <- svydesign(id=~1, data=General, strata=~Grade.Level)
Warning message: In svydesign.default(id = ~1, data = General, strata = ~Grade.Level) : No weights or probabilities supplied, assuming equal probability
summary(survey)
Stratified Independent Sampling design (with replacement)
svydesign(id = ~1, data = General, strata = ~Grade.Level)
Probabilities:
Min. 1st Qu. Median Mean 3rd Qu. Max.
1 1 1 1 1 1
Stratum Sizes:
Elementary High Middle
obs 312 236 156
design.PSU 312 236 156
actual.PSU 312 236 156
Data variables:
[1] "Grade.Level" "Curriculum" [3]
"Field.Trips" "Residencies" [5] "PTA.Support"
"Community.Open.Performances"
[7] "Visual.Arts.Attendance" "Literary.Arts.Attendance" [9]
"Arts.Organization.Membership" "Arts.Essential"
> svymean(~Curriculum, survey)
mean SE Curriculum NA NA ??? PJ
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Thomas Lumley Assoc. Professor, Biostatistics tlumley at u.washington.edu University of Washington, Seattle