Category Archives: Sampling

10 Jan

Reflections on The DHS Program’s Regional Sampling Workshop

In some developing countries, the knowledge and methods for complex survey sampling can be capacity gaps in national statistical offices. In many cases, survey samples are prepared by statisticians who have limited academic and field experience in sampling. For this reason, The DHS Program has developed a Regional Sampling Workshop to provide a two-week face-to-face training on survey sampling. The target audience includes statisticians from African and Asian national statistical offices or implementing agencies who have been or will be involved in designing the sample for their country’s DHS survey. The DHS Program has facilitated two such workshops in Tanzania in 2016 and Indonesia in 2017.

In July 2017, my colleague Dr. Ruilin Ren and I facilitated the Regional Sampling Workshop in Bali, Indonesia. Fifteen participants from nine countries first completed pre-work online in preparation for attending the 12-day face-to-face workshop. The workshop focused on each step involved in survey sampling including sampling frame preparation, sample selection procedure, sample size determination, sample allocation, household listing, and weight calculation. Each day, participants were exposed to innovative blended learning methods, such as videos, demonstrations, exercises, and lectures.

In addition to the sampling topics, participants were introduced to the adult learning principles training package designed by DHS Senior Advisor for Capacity Strengthening, Abibata Handley. Through participatory sessions, participants learned how to apply effective training methods and techniques to teach complex sampling concepts. Participants worked together in groups to develop and facilitate a 60-minute “teachback” for one of the sampling topics and received feedback from the instructors. I was impressed by how creative all the groups were in facilitating their assigned sessions. Upon completion of the workshop, participants were ready to go back to their home institutions and teach sampling topics in an interesting way.

Many programs provide sampling training, but what makes The DHS Program’s capacity strengthening and training workshop unique is its combined use of traditional training approaches along with cutting-edge eLearning tools. This combination provides participants with practical skills that can be applied right away to support their country’s ongoing surveys. Participants receive the entire training package so they can, in turn, replicate the sampling training in their own country. The training package includes a Facilitator’s Guide and Participant’s Guide, presentations, and tools with detailed instructions on how to facilitate the activities, class exercises, and group projects.

In May 2017, I traveled to Yaoundé, Cameroon to provide technical assistance in the sample design for the 2017-18 Cameroon Demographic and Health Survey. During the trip, I worked with Romain Wounang, a Survey Statistician at the National Institute of Statistics (INS) of Cameroon, who attended the first Regional Sampling Workshop in Tanzania in 2016. In addition to his background and experience in survey statistics, the new skills that Romain acquired from the workshop allowed for a smooth collaboration in designing the sample for the Cameroon DHS. This experience was a success, as I witnessed a participant perform and apply the sampling techniques covered in the workshop to the sample design of the Cameroon DHS.

Another workshop participant, John Bore from Kenya, excelled and was approached to be a co-facilitator for a Tanzania-specific sampling workshop. When asked to help with the training, without hesitation John accepted and lead several sessions. As he kicked off the workshop, John introduced himself:

“Good morning everyone. My name is John Bore. I am a Senior Statistician from the Kenya National Bureau of Statistics. Eight months ago, I myself was sitting in your seats. I was a participant at the first-ever DHS Program Regional Workshop on Sampling and Listing that was held in Dar es Salaam, Tanzania in July 2016. Today, I am here as a co-facilitator. It’s an honor to be co-facilitating this workshop along with our DHS sampling expert, Dr. Ruilin Ren.”

To date, The DHS Program has trained 31 samplers and consultants in regional workshops.  Although the sampling workshop is just one activity in a long process to prepare professional sampling statisticians, I believe conducting such trainings is a win-win strategy for the participants, implementing agencies, and for The DHS Program.


Photo captions: 1) Participants from the 2016 Regional Sampling Workshop in Dar es Salaam, Tanzania; 2) Participants from the 2017 Regional Sampling Workshop in Bali, Indonesia; 3) Survey sampling online pre-work  course sections; and  4) John Bore, co-facilitator at the Tanzania-specific sampling workshop in Dar es Salaam, Tanzania.

30 Mar

Model Datasets to the Rescue

Have you ever wanted to start immediately working on a DHS dataset, but didn’t have a research topic? Or didn’t want to take the time to register for access? Well, The DHS Program now has the cure for all your data analysis woes!

The DHS Program has created model datasets so users can become familiar with datasets without having to register for access. These datasets have been created strictly for practice and do not represent any country’s actual data. Model datasets are based on the DHS 6 Questionnaire and Recode. They include data on all standard survey characteristics, as well as data on domestic violence, female genital cutting, adult and maternal mortality, and child labor.

You might be thinking, how can I use these datasets? Model datasets can be used for many different purposes, including:

  • Replicating standard final report tables
  • Practicing calculating complex indicators
  • Teaching statistical concepts and procedures

Team members from Nigeria participating in the 2016 Regional DHS/MIS Malaria Analysis Workshop

Recently, the model datasets were used in the 2016 Regional DHS/MIS Malaria Analysis Workshops in Uganda and Senegal. Since participants attending the workshop came from different countries with different DHS/MIS datasets, the curriculum and workshop exercises were standardized using the model datasets. After going through the model dataset examples, participants then worked with their country’s specific data to match numbers in the final report. This was a great way for facilitators to make sure everyone was mastering the skill before participants worked on their own country’s data.

Model datasets have already had a starring role in our sampling and weighting tutorial videos. Future videos will also feature the model datasets, allowing users to follow along with the examples in the tutorial with their own statistical program.

Visit the Model Datasets page on The DHS Program website for more information. Users can pick and choose which data files to download, as well as download the full set of final report tables and sampling errors to check their work. Again, unlike datasets for specific surveys, users do not need to register in order to gain access.

If you have recently used the model datasets we want to hear from you! Comment below or email modeldatasets@dhsprogram.com to share your experiences with the model datasets or how you plan on using them in the future. You can also post questions about the model datasets on the User Forum.

16 Sep

Sampling and Weighting with DHS Data

At long last, The DHS Program has released two videos which demonstrate how to weight DHS data, concluding the Sampling and Weighting video series.

2012 Tajikistan DHS

2012 Tajikistan DHS

The first video in the series, Introduction to DHS Sampling Procedures, as well as the second
video, Introduction of Principles of DHS Sampling Weights, explained the basic concepts of sampling and weighting in The DHS Program surveys using the 2012 Tajikistan DHS survey as an example. Read our introductory blog post for more details.

In contrast, the third and fourth videos use an Example Practice Dataset, so viewers can practice weighting DHS data and replicate what is being shown in the videos while they are watching. The Example Practice Dataset was specifically created for DHS data users to have hands-on practice using DHS data in different statistical packages (Stata, SPSS and SAS) and does not represent the data of any actual country.

The third video, How to Weight DHS Data in Stata, explains which weight to use based on the unit of analysis, describes the steps of weighting DHS data in Stata and demonstrates both ways to weight DHS data in Stata (simple weighting and weighting that accounts for the complex survey design).

 

The fourth video, Demonstration on How to Weight DHS Data in SPSS and SAS, is the same as the third video, except it uses the statistical software packages SPSS and SAS instead of Stata.

After watching these videos, you will be able to answer the following questions:

  • Which weights should I use for my analysis?
  • What are the steps of weighting data in a statistical software package?
  • How do I weight DHS data in Stata, SPSS or SAS?
  • How do I account for the complex sample design when weighting in Stata, SPSS or SAS?

If you have more questions, visit the user forum!

What did you learn from the sampling and weighting videos? What would you like to explore further? Comment below!

24 Oct

Introducing: Sampling & Weighting at DHS

In my travels as a DHS sampling statistician, I have met countless people who want to hear about the sampling techniques and procedures we use in DHS surveys. Recognizing this fact, we are working to incorporate more sampling-related capacity strengthening activities at The DHS Program. The feedback we get after these activities has only encouraged us to produce more learning tools highlighting basic sampling-related concepts and topics used in DHS surveys.

2012 Tajikistan DHS

2012 Tajikistan DHS

We created a 4-part video series (the next two will be coming within the year) designed to introduce DHS sampling concepts, two of which were launched around World Development Information Day. In the videos, we present the sampling design and procedures used in the 2012 Tajikistan DHS survey as an example of sampling procedures in DHS surveys.

The first video, Introduction to DHS Sampling Procedures, explains the basic concepts of sampling, introduces the stages of designing a sample in a DHS survey, and discusses the key factors to consider when calculating sample sizes for a DHS survey.







The second video, Introduction of Principles of DHS Sampling Weights, introduces the concept of weighting survey data.  You will understand the goals and the importance of weighting as well as the concepts of over- and under-sampling.






Both videos introduce you to the basic sampling definitions, concepts, and procedures followed in a standard DHS survey. If you are interested in more information about the sampling procedures in the DHS surveys, you can check out the DHS Sampling and Household Listing Manual. If you have more questions, check out the user forum!

What did you learn from the sampling & weighting videos? What would you like to explore further? Comment below!

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