Home » Data » Sampling and Weighting Webinar June 2015 » June 3rd Webinar Analyzing DHS Data: Weights and other adjustments for the survey design
| June 3rd Webinar Analyzing DHS Data: Weights and other adjustments for the survey design [message #4327] |
Fri, 08 May 2015 13:56  |
Sarah-DHS
Messages: 54
Registered: February 2013
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Wondering when to weight your DHS data? Struggling with sampling weights in multilevel analyses?
Join us for The DHS Program Analysis Webinar on June 3, 2015 at 10-11 am EST (UTC/GMT-4).
Panelists include:
-Tom Pullum, PhD, Senior Advisor for Research and Analysis
- Ruilin Ren, PhD, Senior Sampling Technician
- Mahmoud Elkasabi, PhD, Sampling Statistician
Submit your questions in advance on the User Forum, here.
Then, join us live June 3rd 10-11am EST(UTC/GMT-4) via Adobe Connect, here, to hear the answers to your questions and more!
The webinar will be recorded and posted on the User Forum for those who cannot join us live on June 3, 2015, and a summary of the questions and answers will be added to the User Forum for easy searching.
For more information, contact Erica Nybro erica.nybro@icfi.com [Updated on: Wed, 03 June 2015 09:48] by Moderator Report message to a moderator |
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| Re: June 3rd Webinar Analyzing DHS Data: Weights and other adjustments for the survey design [message #4335 is a reply to message #4327] |
Sat, 09 May 2015 05:59  |
philiobas
Messages: 1
Registered: October 2014
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Member |
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Please address this problem in the forth coming webinar:
I am applying a two stage stratified sampling techniques for my survey:
At the first stage, we have 6 sectors with their populations known and 4 sectors were selected. At the second stage with each of the 4 selected sectors having varied sub-divisions and a total of 24 number subdivisions are to be selected but the population of the each subdivision is unknown. These subdivisions shall be my PSU. Do I collect equal sample from each of the selected PSU (subdivisions) to make up my total sample size? If I do that, what weighting techniques do I apply to correct for under and over sampling. Please I want to understand how to do this weighting techniques. Thanks
Phillips
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| Re: June 3rd Webinar Analyzing DHS Data: Weights and other adjustments for the survey design [message #4343 is a reply to message #4327] |
Mon, 11 May 2015 03:49 |
MBruederle
Messages: 11
Registered: August 2014
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Member |
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Dear panelists,
I would be grateful if you could address the following questions:
Even though the sampling is usually designed for the data to be representative only at national level, I would like to use DHS data to calculate development outcomes at the local level (clusters or sub-national administrative areas). For example, I want to analyze how local environmental conditions are associated with development indicators as measured by DHS data.
Is it justified to consider over- / undersampling of certain strata in certain localities as noise (considering that my analysis covers an entire country)?
Should I still apply sampling weights to reduce the risk of bias? Or do the weights make no sense if I analyze the data at subnational level?
In general, where do I find information on which covariates underlie the sample selection for each survey? Next to geographic distribution and urban / rural, are households selected (and weights assigned) based on other covariates like ethnicity, family size, ..., to ensure that the sample is nationally representative?
Many thanks.
Anna Brüderle
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| Re: June 3rd Webinar Analyzing DHS Data: Weights and other adjustments for the survey design [message #5474 is a reply to message #4327] |
Thu, 28 May 2015 10:46 |
colinodden
Messages: 2
Registered: June 2014
Location: Ohio, USA
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Dear DHS Panel,
I'd be grateful if you could address the following, which dovetails with a previous poster's question (pooling surveys within country). Many thanks in advance for whatever advice you're able to provide in the limited time you have during the webinar.
(1) The birth histories are very valuable. However, weights are intended to make respondents representative of the population at time of interview, yet births are not occurring at that time. Is this problematic for birth history analyses, and is there a clear resolution? Further, births are not 1:1 with respondents, so the mean weight of births (when applying the respondent's weight to each birth) will not equal 1. On face it seems sensible to weight births by the respondent's weight divided by parity of time at interview, but this of course down-weights births to higher-parity respondents.
(2) Another poster raised the question of how to weight when pooling surveys within country. Pooling surveys within country compounds the benefits of the birth history data, too (we can obtain birth histories spanning up to several decades), but perhaps compounds the problem I indicate in #1 above. In fact, pooling surveys can (and often does) lead to overlapping birth histories, that is, births within an historical period occurring to women in different surveys. Do you have recommendations for how to sensibly weight births when histories overlap surveys?
Cheers!
Colin Odden
Ohio State University
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| Re: June 3rd Webinar Analyzing DHS Data: Weights and other adjustments for the survey design [message #5514 is a reply to message #4327] |
Tue, 02 June 2015 12:38 |
AZett
Messages: 1
Registered: June 2015
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Member |
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Dear DHS panel,
For me it is the first time to work with DHS data, so I would appreciate if you could also clarify some of the basics that need to be accounted for when using DHS data.
Working in Stata, my understanding of the DHS weights so far is, that I need to use survey (svy) commands in order to be able to use p-weights (please correct me if using p-weights is wrong). However, it is unclear to me how to find out how to correctly svy set the data, as I do not know what the correct strata(s) and PSU and SSU would be and whether I need to use FPC. How can I find out which would be correct?
I plan to use data on several countries, can I rely on the assumption that the strata(s) and PSU will be the same for different countries?
Another questions on the weights: Can weighted data still be considered representative when looking at (sub)regions?
If representativity at the subnational scale can not ne guaranteed by using the weights, are poor households systematically oversampled (or undersampled) in general, but more specifically in some regions, so that using unweighted regional data would lead to a clearly misleading picture or are sampling techniques likely "random enough" to reflect general regional patterns in the unweighted data?
Thank you very much in advance.
Looking forward to the webinar tomorrow.
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| Re: June 3rd Webinar Analyzing DHS Data: Weights and other adjustments for the survey design [message #5533 is a reply to message #4331] |
Wed, 03 June 2015 11:24 |
lkondos
Messages: 1
Registered: June 2015
Location: Washington DC
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Dear Sarah,
Thank you for the webinar. I had a follow up question about the independence assumption violation referred to by Dr. Pullum - I have heard others say that the DHS surveys are not independent over time also but I don't understand this: while you may not have an independent probability of being selected within an EA during a DHS in 2011 for example, another DHS in 2015 may not use the same sampling frames which would make the essentially keep each DHS independent of each other. I am asking because we want to look at multiple DHS over time (both across individual countries over time and across multiple countries, comparing them over time but not pooling the data), I make the assumption that each DHS in independent of the one before it but I have been told I need to adjust for repeated measures. Is this accurate?
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