22 Jan 2015

Spotlight on New Staff: Shireen Assaf

This part of a series of posts introducing readers to new staff at The DHS Program. Welcome,Shireen!

Shireen Assaf, Senior Research Associate

Shireen Assaf, Senior Research Associate

Name: Shireen Assaf

Position title:  Senior Research Associate

Languages spoken: English, Arabic and basic Italian

When not working, favorite place to visit:  Lebanon and Italy

Favorite type of cuisine: Mediterranean food (especially Middle-Eastern and Italian) but I also love Thai and Japanese.

Last good book you read: The Shoemaker’s Wife.

Where would we find you on a Saturday?  Either in some sort of exercise class or visiting my sister and her family in Arlington.

First time you worked with DHS survey data: During my Masters studies.

What is on your desk (or bulletin board/wall) right now?  Pictures of family and old pictures of Palestine.

Special Report on Intervention Zones in Niger based on the 2012 DHS

Special Report on Intervention Zones in Niger based on the 2012 DHS

What is your favorite survey final report cover?  The Special Report on Intervention Zones in Niger based on the 2012 DHS. Just look at that  face!

Favorite chapter or indicator, and why?  If I had to choose one indicator perhaps it would be modern contraceptive use. This one indicator can give you a lot of insight about a country, from demographics to gender issues.

What’s your favorite way to access The DHS Program’s data? STATcomplier for quick access to indicators and trends, and The DHS Program website for the final reports and other published material.

What population or health issue are you most passionate about?  Why?

Family planning and gender issues. So much still needs to be achieved in these areas and studying the factors associated with them is one of the issues I am passionate about. I am also very passionate about studying trends in various health indicators both temporal and spatial.

What are you most looking forward to about your new position?

I look forward to working on different analytical and research studies each year for different countries and topics. I love research and analysis and I am happy to be in a position that allows to me conduct analysis on new topics using new data each year. I am also looking forward to learning from my work here and from my colleagues who are all very cooperative and great to work with.

What has been your biggest surprise so far?

The national diversity of The DHS Program team. Also the amount of work required to manage the DHS in all its aspects; survey management, training, data processing, analysis, and dissemination.

What do you look forward to bringing to The DHS Program (job-related or not!)?

I look forward to bringing my research and analytical skills and to contributing the best of my abilities to The DHS Program research activities.

13 Jan 2015

Harnessing Technology to Streamline Data Collection

By Guillermo Rojas

The survey process at The DHS Program takes an average of 18-20 months and goes through several steps: survey preparation and questionnaire design, training and fieldwork, data processing, and finally, writing the final report and dissemination. But how do the data get from respondents’ households into the tables you see in the final report?

We employ field interviewers to ask respondents the questions included in the DHS questionnaires – household, woman’s, man’s, and biomarkers. But the way we record their answers changes based on the data collection methodology. At The DHS Program, we employ three types of methodologies to collect data: paper questionnaires, Computer Assisted Field Editing (CAFE), and Computer Assisted Personal Interviews (CAPI).

DHS Model Household Questionnaire, Page 1

DHS Model Household Questionnaire, Page 1

The vast majority of DHS surveys in the past 30 years have used paper questionnaires to collect data. With physical paper questionnaires in hand, field interviewers go from house to house, ask the questions of the respondents, and manually fill out the questionnaires. After interviewers visit all households within a cluster, supervisors ship the questionnaires to the survey central office. Upon arrival, the data processing begins for that particular cluster.

The Computer Assisted Field Editing (CAFE) system allows for editing to happen as interviews are taking place. With CAFE, interviewers still use paper questionnaires, but Field Editors enter the questionnaires into computers while the team is still in the cluster. Essentially, questionnaires are fully field edited by an intelligent data entry program. With this type of data collection approach, Field Editors provide feedback to interviewers on any anomaly identified by the program such as interviewers missing full sections of the questionnaire or wrongly executing critical skip patterns. At this point in the survey process, it is relatively easy to send the interviewer back to the household to resolve any problems. With this approach, there is no need for main data entry as the data entered in the field is sent via the internet to the central office. Therefore, CAFE speeds up the survey process as cluster data files are available as soon as the data arrive to the central office for further processing.

The 2005 Colombia DHS was the first DHS survey to utilize the Computer Assisted Personal Interview (CAPI) methodology. CAPI does not involve any type of paper questionnaire—it is entirely digital. Back in 2005, field interviewers used bulky laptops, though nowadays we use lighter tablets and notebook computers.

Fieldwork in the 2005 Colombia DHS

Fieldwork in the 2005 Colombia DHS

The DHS CAPI data collection system consists of three comprehensive subsystems:

1. A system for interviewers to facilitate the interview process

2. A system for supervisors to centralize the data collected by interviewers

3. A system for the central office to monitor the fieldwork operation and to further process the data

The DHS CAPI system uses Bluetooth technology to transfer and share data among members of the same fieldwork team. Supervisors then send data to the central office headquarters using the Internet File Streaming System (IFSS), a cloud-based electronic file delivery system developed by The DHS Program. The primary objective of the service is to deliver files from one user to another in an exceptionally fast and secure way.

In the past 30 years, we’ve witnessed an incredible change in technology, especially with both hardware and software. When I first started at The DHS Program, running the program to impute the woman’s events dates could easily take more than six hours for a survey with a sample size of 2,000 to 3,000 households! Nowadays, with sample sizes of 20,000 to 30,000, this program takes just one to two minutes to run. CAFE and CAPI allow us to use the power of these newer innovations in technology to make sure that we carry out DHS surveys as efficiently and accurately as possible.


Guillermo Rojas is Chief of Data Processing at The DHS Program. He has more than 35 years of experience in computer science and survey data processing, and has provided data processing technical assistance and training for more than 20 surveys. Since the early stages of The Demographic and Health Surveys (DHS) program, Mr. Rojas has been involved in the design and development of the data processing methodology currently being used to process and analyze DHS surveys. He is the primary writer of the master programs for implementing the evolving data processing methodology. Mr. Rojas coordinates all DHS data-processing activities and supervises personnel to ensure the accuracy and quality of the processes implemented.

07 Jan 2015

Video: Interview with Martin Vaessen, Former Director of The DHS Program

We sat down with Martin Vaessen, former director of The DHS Program, to hear his thoughts about the past 30 years of The DHS Program. Martin is a demographer and survey specialist with more than 35 years of experience providing technical assistance in all phases of survey implementation in developing countries. He was instrumental in achieving the incorporation of HIV testing in the  Demographic and Health Surveys (DHS), an innovation that led to a revision of the estimated number of people living with HIV from 40 million to 33 million in 2007.


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Anthropometry measurement (height and weight) is a core component of DHS surveys that is used to generate indicators on nutritional status. The Biomarker Questionnaire now includes questions on clothing and hairstyle interference on measurements for both women and children for improved interpretation.