RDD sampling in developing regions: Middle East and North Africa

Utilizing Mobile Random Digit Dialing (RDD) Sampling Frames for Population Surveys in low- and middle-income countries in the Middle East and North Africa

Just like our prior posts concerning RDD survey sampling in emerging nations like Sub-Saharan Africa and Latin America, significant surges in mobile phone adoption are also apparent in other developing global regions. Notably, the Middle East and North Africa have witnessed a substantial upswing in mobile phone ownership in the past 10 years. This trend coincides with a decline in household landline ownership. Consequently, the prevalence of mobile surveys, especially employing mobile RDD, has substantially risen as a primary approach for efficient data collection in this region.

As highlighted in the prior blog entries, random-digit dialing (RDD) is a powerful and representative sampling method for national phone surveys. It involves generating random phone numbers, pre-screening their connectivity, and providing viable samples to survey organizations. This approach is particularly valuable in low-to-middle-income countries where traditional methods like face-to-face surveys face challenges due to inadequate infrastructure, difficulties in reaching remote areas, and low internet adoption which in turn make online surveys unfeasible for the time being.

Yet, mobile surveys in MENA come with their own set of challenges. A key concern is guaranteeing sample representativeness. Household surveys face complexities, as access and equal selection probability aren’t universal. This is especially evident in interviewing women within households, where obtaining consent from the head – often the husband or father – is a notable hurdle.

To address this challenge, researchers can use a set of tools and best practices to ensure sufficient representativeness of female responses, such as contracting female interviewers and incentivizing to gain male consent are some of the most popular culturally sensitive approaches. 

Another challenge is ensuring that the survey is conducted in a way that is culturally appropriate and sensitive to local customs. This may involve adapting survey questions to native and minority ethnic groups’ languages to ensure that respondents understand the questions being asked. As cultural norms and sensitivities can impact respondents’ willingness to participate in surveys, especially on sensitive topics. Researchers must navigate these sensitivities carefully to avoid causing discomfort or offense.

In the face of these obstacles, mobile surveys employing RDD sampling offer a promising avenue for garnering valuable insights across various domains in these emerging nations. Their utility shines through in tasks like gathering data for international program development and assessment endeavors.


When utilizing RDD for Computer Assisted Telephone Interviewing (CATI) survey in MENA countries, several key considerations need to be taken into account due to the unique cultural and social characteristics of the region:

  • Language Diversity:
  • Cultural Sensitivities
  • Gender Dynamics
  • Informed Consent
  • Telephone coverage and frame size

Language Diversity 

Although in the region the predominant language is Arabic in 17 of the total 20 countries these have diverse languages and dialects such as Pashto, Kurdish, and Berber. Ensure that survey questions are accurately translated and culturally adapted for each target population.

Cultural Sensitivities

 Respect cultural norms and sensitivities when designing survey questions and conducting interviews, especially on sensitive topics. 

Gender Dynamics 

Account for gender dynamics when selecting interviewers and approaching respondents, particularly in conservative households where gender interactions are restricted.

Informed Consent

Ensure that respondents fully understand the purpose of the survey and give informed consent before proceeding with the interview.

Telephone coverage and frame size

Key metrics for determining whether a telephone sample frame is sufficient for covering the population are the telephone frame size, subscriber counts (active frame), and the population size of the countries:

Telephone frame size – the sum of all possible phone number combinations that can be generated according to the nation’s numbering plan,  number length, and available dialing codes and prefixes.

Subscriber count – represents the populations that can be reached via a phone number device and/or SIM card.

Population size – the total count of residents that live in the country.

From these key metrics, we can derive crucial information such as how wide the Active Rate (count of subscriptions/telephone frame*100)

And the Telephone Penetration rate:

(count of subscriptions/population*100) – calculate the number of phone subscriptions per 100 inhabitants.

Phone coverage is the count of all inhabitants that have access to at least one mobile device or SIM card.

e.g. In Saudi Arabia’s case, the metrics are:

Population*: 35,950,396 (2021)

Mobile phone frame size**: 79,000,000 

Subscriber count*: 45,427,321 (2021)

Active Rate: 57.5% of the frame is active ~57 of 100 random numbers are expected to be working numbers.

Penetration rate (per 100 inhabitants): 126% – indicated that inhabitants have access to more than one mobile number device and or sim card – hence they have a larger probability of being over-selected in a random sample. Does not have any indication of non-coverage.

*Source: World Bank, 2021

**Source: ITU Numbering Plan for Saudi Arabia

One limitation when we have a high penetration rate among subscribers when calculating these metrics is the over-coverage of respondents owning 2 or more cell phone numbers. This may cause duplication and/or overlapping responses. If individuals provide different phone numbers for each survey, it becomes challenging to identify and eliminate duplicate entries. Additionally, multiple phone numbers may indicate a higher level of technology adoption or socioeconomic status, leading to a potential bias in the sample towards individuals with greater access and resources.

By meticulously considering these factors, researchers can design effective RDD sampling strategies tailored to the MENA region, leading to more accurate and meaningful survey results.

Telephone phone coverage and most common survey topics:

Top 3 Countries with the Highest Cell Phone Ownership in MENA:

1. United Arab Emirates (UAE): The UAE has been known for its high level of technological advancement and connectivity. Cell Phone ownership rates are the highest in the region edging close to 100% cell ownership.

2. Qatar: Similar to the UAE, Qatar boasting an economy and a high standard of living, has contributed to a high level of cell phone ownership and adoption at 99%.

3. Saudi Arabia: with a large and tech-savvy population, The Kingdom of Saudi Arabia has a significant portion of its residents owning cell phones – 99%. The country has been actively investing in digital infrastructure and telecommunications.

Top 3 Countries with the Lowest Cell Phone Ownership in MENA:

1. Libya: Political instability and conflict in Libya have contributed to challenges in infrastructure and access to technology, which may have affected cell phone ownership rates(43%).

2. Yemen: Yemen has faced ongoing conflicts and economic challenges in the recent decade, which have impacted the accessibility and affordability of technology, including cell phones. Its estimated cell phone ownership is 46%.

3. Syria: The civil war and ongoing conflict in Syria have had a significant impact on infrastructure and economic stability, potentially affecting cell phone ownership rates estimated at 80%.

Mobile phone ownership in the Middle East and North Africa

The report showcases mobile phone coverage on the individual level among all MENA nations in the region. Source: World Bank Group, 2021

In this section, we will outline the key facts and figures relevant to mobile sampling for all countries in MENA as well as in which programs and evaluation studies our sampling efforts have been implemented.

Common Survey Topics for MENA:

Our sampling has over the years enabled studies to be conducted using phone interviewing and has played an integral role in study design development for multiple international survey efforts for various fields and by many international organizations and Think Tanks like Arab Barometer, Gallup, World Bank, and other United Nations Agencies, in fields such as:

Gender and Women’s Rights: Surveys can focus on gender roles, women’s empowerment, access to education, healthcare, and workplace equality. Topics related to gender-based violence, early marriage, and reproductive rights are also important.

Political Attitudes and Democracy: Research on political attitudes, public opinion, and levels of trust in political institutions can provide insights into the region’s democratic development, governance, and political participation.

Religion and Identity: Understanding the role of religion in individuals’ lives, as well as its impact on societal values, cultural identity, and political beliefs, is a complex and important research area.

Migration and Displacement: Surveys can explore the experiences of migrants, refugees, and internally displaced persons in the region. Topics include motivations for migration, integration challenges, and social cohesion.

Health and Healthcare Access: Research on healthcare services, access to medical facilities, attitudes towards healthcare, and prevalent health issues can provide insights into the region’s healthcare system.

Conflict and Peacebuilding: Research on attitudes towards peace, reconciliation, and post-conflict reconstruction can contribute to understanding conflict dynamics in the region.

Advantages and Disadvantages of sampling survey respondents Using RDD Methodology for phone survey research in MENA

Advantages of Random Digit Dialing sampling for mobile phone surveys

Among the biggest advantages of mobile RDD in the MENA region, we list:


RDD enables researchers to reach populations that might not be easily reachable through other methods, such as those in rural or remote areas, helping to reduce geographic bias.


RDD allows for efficient data collection by automating the process of generating phone numbers, making calls, and conducting surveys. This can lead to faster data collection and analysis.


By using a random selection process, RDD helps to minimize selection bias, ensuring that each eligible respondent has an equal chance of being included in the sample.

Geographical Coverage: 

RDD allows researchers to gather data from a wide geographic area without the need for physical travel, making it easier to conduct surveys across different countries in the MENA region.

Disadvantages of Random Digit Dialing  sampling for mobile phone surveys

Nonresponse Bias

Despite randomization, not everyone contacted through RDD will participate, leading to potential nonresponse if those who decline have different characteristics than those who participate.

Cultural and Social Factors

Phone surveys might face cultural and social challenges, such as mistrust of unknown callers or reluctance to share personal information over the phone.

Sampling Biases

Despite randomization, certain population groups might be underrepresented due to their phone usage patterns or accessibility to phones.

Best Practices for RDD Mobile Sampling in the MENA Region:

Caller Identification: 

Clearly identify the purpose of the call and the organization conducting the survey to establish trust and legitimacy. Transparency can encourage more respondents to participate.

Informed Consent: 

Obtain informed consent from male respondents about interviewing any females in the household before starting the survey. Clearly explain the purpose of the survey, the estimated time required, and how their responses will be used.

Language Proficiency: 

Identify the languages spoken in different parts of the region and offer surveys in the appropriate languages to ensure that language barriers don’t hinder participation.

Cultural Sensitivity: 

Approach the survey with cultural sensitivity and respect for local customs and traditions. Adapt your communication and approach as needed to establish rapport with respondents. Develop a questionnaire that is culturally sensitive and relevant to the MENA context. Avoid sensitive or controversial topics, and structure questions in a way that is clear and easy to understand.

To sum up, RDD mobile sampling presents a dynamic and effective method for conducting survey research in the Middle East and North Africa. Capitalizing on the prevalence of mobile devices, this approach enables researchers to engage a broader and more varied audience. Nevertheless, it’s crucial to remain attentive to potential issues tied to sample representation, response rates, and technological constraints. By adhering to established guidelines and customizing surveys to fit the regional milieu, this method of sampling emerges as a valuable instrument for gathering data throughout the Middle East and North Africa.

About Sample Solutions

Sample Solutions is a member of the World Association for Public Opinion Research(WAPOR), the organization has presented on numerous occasions related to this topic and provides Dual-frame and single-frame RDD sampling for 170+ countries, including all countries in the Middle East and North Africa for CATI, SMS, and interactive voice response survey (IVR) survey modes. If you have a research project that may require an RDD phone sampling approach for a specific country, we warmly welcome you to request our complimentary Sampling Methodology Whitepaper and country factsheet from our RDD Sample Coverage Page.

Nikola is the Key Account Manager of Sample Solutions and Lifepanel with over 5 years of sampling and survey research experience. Coming from a Business Administration background he discovered a hidden interest in understanding populations' opinions and behaviors both locally and across the globe.

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