|Language of Instruction||English, Spanish|
|Funding State Governments||New York, Texas, California; Private Sector: AT&T, ETS; National NGOs: Service Employees International Union: Los Angeles Public Library, International NGO: Discovery Learning Alliance; CARE|
|Foreign Donors||UKAID; Disney Foundation|
|Annual Programme Costs||902,000 USD (2017)|
|Date of Inception||August 2011 RCT (randomized controlled trial), Launch 2014|
Country Context and Background
The United States of America (USA) has been a destination for immigrants for more than 150 years, and this trend continues today. In 2015, the immigrant population was more than 43.3 million, representing 13.5 per cent of the total population (Migration Policy Institute, 2017). However, for millions of immigrants, participation and inclusion in mainstream society remain a challenge, mainly due to their low literacy and numeracy skills. Roughly 40 per cent of adult immigrants in the USA lack basic English literacy skills, and 48 per cent lack basic numeracy in English (Batalova and Fix, 2015).
Beyond immigrant populations, the problem of low literacy and numeracy skills is also prevalent among American citizens. Statistics from the OECD’s Survey of Adult Skills show that, out of 23 countries, the USA ranks 16th in literacy proficiency, 21st in numeracy proficiency, and 14th in problem solving in technology-rich environments (OECD, 2016). Indeed, a huge number of adults in the USA lack functional literacy and other basic skills necessary for day-to-day activities, such as filling out job applications or deciphering public transport timetables. Low literacy and numeracy not only deprive an individual of his or her opportunities for a better life, but also hinder the social and economic development of society as a whole.
There are multiple literacy interventions available, such as language and numeracy courses offered by private language schools, community learning centres and local libraries. However, it is difficult, if not impossible, for people with limited literacy skills and low income to regularly attend these courses due to a myriad of obstacles – for example, some are unaffordable. But, even where these courses are free of charge, it is difficult for adults to spare the time to attend, due to their demanding work schedules (many hold down multiple low-paid jobs to earn their livings) and family duties. Lack of transportation is another barrier. In some cases, undocumented immigrants fear that they risk deportation if they register for such courses. Thus, although it is imperative to provide this particular population with opportunities to enhance their literacy and numeracy skills, to do so is a challenging task.
Overview of the programme
The Cell-Ed programme (Cell-Ed) endeavours to address the challenges mentioned above by teaching adults essential skills – reading, writing, oral communication, numeracy, work and social skills – via any type of mobile phone (basic models or smartphones), tablet or computer, even without an internet connection or expensive data plan. This idea is based around two factors: the affordability of cell phones and their wide usage in society. The number of mobile phone users in the USA was predicted to hit 266 million in 2017 (Statista, 2017), which would mean that more than 82 per cent of the total population would be using mobiles. Moreover, while 98 per cent of the adult population has access to a mobile phone, only 20 per cent attend classes in person or go online for further learning and education (OECD, 2016). The discrepancy between these numbers, while large, is not surprising since cell phones, especially basic mobile phones, have become more affordable and are now an essential part of daily life. Hence, Cell-Ed has built its programme by harnessing the enormous potential that cell phones offer for adult education, especially in reaching socially, economically and culturally marginalized adults. By taking courses provided by Cell-Ed over their cell phones, people with low literacy skills can practise and enhance their literacy and other essential skills, despite the time deficit and financial constraints they face.
Cell-Ed began as a research project in 2011, and aimed to test whether non-literate adults could learn to read better over a basic cell phone. From 2012 to 2014, a randomized controlled trial (RCT) was conducted as a pilot project by researchers from the University of California, Los Angeles, Tufts University in Massachusetts, and Oxford University in the UK. The course used for the pilot project was based on a traditional Spanish adult education programme (LEAMOS!), developed by the Centro Latino in Los Angeles. Results from the RCT showed rapid progress among learners, who leaped forward by two years in basic reading skills while using Cell-Ed for four months (Ksoll et al, 2014). Along with these improved reading skills, learners’ efficacy and confidence also greatly increased. Hence, based on these promising findings, Cell-Ed started to design and deliver its literacy and education service by turning mobile phones into classrooms and teachers for low-literate and low-income adult learners.
As a social enterprise, Cell-Ed is a for-profit business that reinvests its surpluses back into improving and expanding its literacy, education and jobs skills programmes. Cell-Ed also has fiscal sponsorship that allows for charitable contributions and donations. Not only does Cell-Ed make its courses universally accessible but also collaborates with local governments, adult education providers/organizations and major employers to introduce and promote its platform and courses among more targeted adult learners. Since 2014, Cell-Ed has reached more than 10,000 non-literate and low-literate adults in the USA. As an education technology provider, Cell-Ed equips adult learners with effective instruction and tuition in literacy, language and work skills over any type of mobile phone, which allows them to learn anywhere and at any time on any phone.
Aims and Objectives
Cell-Ed aims to generate positive changes in the lives of disadvantaged groups of adults in the USA by providing them with opportunities to engage in learning and to enhance their literacy and other related skills.
Cell-Ed’s specific objectives are:
- To make literacy, language and job-related skills courses accessible at any time for any interested adult learners
- To develop learning content that covers literacy and essential skills and meets the needs of individual learners
- To understand learners’ educational goals, needs and progress with surveys, a detailed needs assessment and a landscape analysis through the Cell-Ed platform
- To edit and update learning content based on responsive answers received from learners through the Cell-Ed platform
Programme Content and Implementation
The courses are designed by Cell-Ed experts who are either experienced certified teachers or education professionals with masters or PhD-level qualifications in the field of education technology design for low-income and low-literate populations. This curriculum development team therefore combines comprehensive technical expertise with extensive field and practical teaching experiences. Catering for non and low-literate adult learners, it has created a series of micro-lessons on building up literacy-related skills to help learners continue to improve, both in formal and informal learning environments. As well as the curriculum for learners, the curriculum development team also develops teachers’ guides.
Below are Cell-Ed’s four main courses:
Learn to Read (Vamos a Leer)
This course teaches basic reading and writing in English and Spanish through a phonetic approach to literacy instruction. It contains 48 units and takes approximately 40 hours to complete. The lessons cover the names and sounds of vowels and consonants, and how to combine syllables to make words and sentences. The course also focuses on teaching high-frequency words. The target learners of this course are low-literate English and Spanish speakers who may benefit from a basic literacy course before starting other Cell-Ed courses.
English on the Go!
This programme uses an essential skills approach to English language instruction. It is organized around the key skills necessary for navigating daily life. For example: how to talk to a doctor, manage finances, apply for schools and jobs, and so on. English language learning courses are aligned with widely accepted standards, including the BEST Plus from the Centre for Applied Linguistics for assessing adults’ English proficiency. In this way, learners’ needs are identified and addressed by reliably demonstrating their progress. This course falls into two categories: one for English speakers – All English Program Levels 1-5 – and one for Spanish speakers – Level A and Level B; each level has between one and five sub-levels and consists of 10 or 11 units beginning with an Introduction and Review Unit. After that, each one touches upon a scenario or situation in which learners would need to apply literacy and numeracy skills. The goal is to equip learners with the ability to cope with similar situations in real life. As well as key vocabularies, common expressions, conversations and points of grammar, they also learn relevant information and knowledge related to each topic. Upon completion of each level, students take a final review of what they have learnt before completing an assessment, which provides Cell-Ed and its customers with data regarding each individual learner’s strengths and weaknesses in regards to the respective course level. Figure 1 below offers a glimpse of the curriculum for this course.
|Units||Purpose||Grammar / Vocabulary|
|Unit 1: Introduction to Cell-ed and English||Talking about daily schedules and habits|| Present tense; negative sentences with
don’t / doesn’t
|Expressing ability||Can / can’t|
|Defining common activities and days of the week||Vocabulary about activities; days of the week|
|Interpreting data / charts||Reading and interpreting work schedules|
|Unit 2: Jobs and industry||Asking about work|| Review of questions with
|Recognizing job title||Vocabulary for types of jobs and industries|
|Identifying responsibilities of various jobs||Vocabulary for common job responsibilities|
|Unit 3: Official Documents and Paperwork||Interpreting forms and documents||Common vocabulary on forms: surname, date of birth, months of the year|
|Explaining actions happening in the moment||Present continuous|
|Describing family relationships||Vocabulary for family members|
|Calculating age||Using date of birth to find age|
|Unit 4: Shopping||Bargaining and understanding prices||Questions: How much?|
|Understanding sizing and fit||Vocabulary for shopping: names of food and clothing items|
|Giving advice and solving problems||Should / shouldn’t|
|Calculating the total prize||Adding prizes|
|Unit 5: Dining out||Asking about preferences||Questions: What would you like?|
|Ordering food and drinks||Statements with I’d like|
|Talking about future plans||Introduction to will|
|Unit 6: Practice, Review and Expressions||Giving advice and asking for help||Could / should / would|
|Talking about future plans||Review of will ; introduction to going to|
|Expressing possessions||Review of project pronouns|
|Unit 7: Taking Care of Your Health||Describing the past||Simple past; statements and questions|
|Explaining symptoms||Vocabulary for common symptoms; body parts|
|Understanding preventive health||Imperatives and advice|
|Measuring and interpreting time||Describing length of time to a doctor|
|Unit 8: Making plans||Describing the past||Irregular verbs in the past|
|Making plans|| Review of
|Offering well wishes||Phrases for congratulation|
|Unit 9: Asking for help||Asking for help and favors||Indirect questions with Could|
|Responding to requests||Phrases to accept or decline requests|
|Expressing common actions||Collocations with make|
|Unit 10: Getting directions||Asking for directions||Questions: How do I?|
|Interpreting common actions||Phrasal verbs with get: get in / out, get on /&thinsp:off, get up, get + adjective|
|Distinguishing directions||Vocabulary for directions: turn, right, left, close, far, near|
|Noticing patterns||Interpreting public transportation schedules|
|Unit 11: Practice, Review and Expressions||Differentiating long and short vowel sounds||Pronunciation of of short i and long e|
|Describing indefinite things||Something, everything, anything, nothing|
|Understanding meaning through context||Common expressions including take it easy, everything happens for a reason …|
|Prioritizing tasks and organizing time||Making and analyzing to-do lists|
|Final Review||50 review exercises for language taught in unit 1 – 50|
|Final Assessment||50 assessment questions to assess learning gains in this course|
Citizenship on the Go!
This course provides immigrants who have a good command of English with the knowledge to pass the USA naturalization exam. It also reviews the key vocabularies needed to pass the English reading and writing sections of the exam. This course is taught entirely in English.
Skills on the Go (job, health, other)!
These courses are off-the-shelf or customized in conjunction with customers. Many companies and organizations need to deliver staff training over mobile phones, either to complement their in-house staff training or as stand-alone instruction. Thus, upon request, Cell-Ed develops different courses for its community-based customers, such as health clinics, community centres, community libraries and information centres. To achieve this, Cell-Ed makes technological and media modifications to training materials provided by customers so that the materials become more engaging, relevant and effective. Examples from a collaboration with a group of healthcare centres include ‘Understanding your Baby’, ‘Talking with your Doctor’, and ‘Fighting Cancer’. All the materials are reconfigured into a series of three-minute lessons before being uploaded to the Cell-Ed platform, ready for customers and learners to use. In cases where no suitable materials exist, Cell-Ed’s five-strong in-house team, with help from external experts where needed, develops training materials from scratch according to specific customer requirements. For instance, in collaboration with labour unions, employers, adult learning centres and library systems, Cell-Ed has developed entirely new job-skills training courses. Although learners take these courses through their cell phones, upon request from customers, Cell-Ed has also delivered some courses through physical workshops to reinforce the information covered.
Approaches and Methodologies
Access to Cell-Ed
All Cell-Ed courses are completely free of charge for learners. However, if learners do not have a mobile phone plan with unlimited talk and text, regular phone charges may apply for the calls and texts they make during their lessons. Thus, upon starting the Cell-Ed courses, learners are encouraged to talk to their mobile phone providers for more information on their specific plan or to find a plan with unlimited talk and texts (flat rate package). To start the programme, learners call the Cell-Ed service number by using their cell phones, either basic or smart. When prompted, they enter a PIN code, which they will have received from Cell-Ed’s customer services department. Next, learners complete a pre-assessment and a needs assessment to ensure appropriate placement and personalization.
Once learners enter into a lesson, they first listen to an audio introduction. Next, they receive a text message (SMS) on their cell phones. Without hanging up the phone, they open the SMS while continuing to listen to the lesson. The automated Cell-Ed ‘teacher’ (a voice recording of a Cell-Ed live coach), explains the information contained in each SMS. At the end of each lesson, learners respond to questions that have been texted to them using vocabulary or grammar they have learned in the lesson. If learners send the correct answers, they are allowed to continue on to the next lesson, otherwise, Cell-Ed helps learners by sending additional instructions. Where learners do not know the correct answers or fail to understand instructions, a live Cell-Ed coach can step in and provide extra help via SMS or a voice phone call. Since the courses contain significant amounts of back-and-forth text messaging, learners need to know how to receive and send text messages while on a call.
Since spring 2017, learners have also been able to use their smartphones or tablets to download the Cell-Ed app – if a learner has an Android phone they can find this in the Google Play store; iPhone users will find it in the App store. Next, the learner clicks on ‘New Learner’ and provides their cell phone number, with country codes and the PIN code. New learners will also create a password. After choosing a specific lesson, learners will receive a confirmation code via SMS to start the lesson online. The only cost to the learner when using the Cell-Ed app is for data access or Wi-Fi. Lastly, learners can access Cell-Ed through a computer by going to gocelled.com. Similar to the app process above, the learner clicks on ‘New Learner’ and enters the PIN code to get started.
Key Features of Cell-Ed
Highly accessible, self-paced and self-directed. As it is an automated programme, Cell-Ed courses are available 24 hours a day, seven days a week. Therefore, learners can study as many lessons as they like, whenever they like. All the courses are self-paced, which means that individual learners can decide how long to spend on each lesson, and can start and stop at their convenience. If they have to hang up or log off in the middle of a lesson, they are able to start from where they left off when they call or log in again. Learners do not lose their progress or information, even when they switch from using Cell-Ed on a tablet at the library to a flip phone back at their home, because of a feature called cross-platform compatibility. If they want to practise what they have learnt, learners can repeat and revise any lesson at any time.
Personalized support from a live coach. Cell-Ed is not merely a platform that offers various courses via mobile devices. Rather, it offers learners the opportunity to engage in interactive and supported learning with help from live coaches. When learners register with Cell-Ed, a live coach is automatically assigned to them. Hence, whenever a learner encounters problems and difficulties with a lesson, he or she can ask for help and guidance from his or her live coach via a simple SMS or phone call.
Highly relevant and learner-friendly lessons. The essential skills covered in these courses are grounded in learners’ everyday realities, in both their personal and professional lives. Likewise, learners are assigned to different courses based on their learning needs and level of competency. As a result, the learning content is relevant and interesting to them, and they are better motivated to continue with their studies. While on the app, learners can also track their own progress easily.
Moreover, all the courses contain micro or bite-sized audio lessons, which last only one to three minutes because research shows that adults learn more effectively in short, easily digestible bursts (Evans, 2014). In this way, low-literate adult learners become more focused, motivated and effective in the learning process.
Enrolment of Learners
Cell-Ed’s target users are low-literate and low-income adults who want to enhance their literacy and other basic skills in order to pursue positive changes in their lives. Cell-Ed reaches potential learners by working closely with its community-based customers, e.g. libraries, literacy associations, school networks, employers and government agencies. These organizations spread information on the Cell-Ed programme and its access codes within their institutions. Each customer organization has its own unique Cell-Ed PIN code.
Adults who want to improve their skills via Cell-Ed can register by calling the Cell-Ed service number or downloading the Cell-Ed app. While registering, learners take an automated assessment test to gauge their literacy levels and learning needs. Based on the results of this test, learners are assigned to specific courses and a live coach, and can immediately begin to learn.
Recruiting and Training of Live Coaches
Cell-Ed’s live coaches play an important role in providing learners with timely and personalized support for their learning process. They are bilingual certified instructors, who provide explanatory and technical advice ¬– most are teachers or former teachers. All coaches must understand how the Cell-Ed system functions, both pedagogically and technologically, and be open and willing to help students as issues arise. Many coaches are full-time, but additional support is also provided by coaches who work part-time and are paid at an hourly rate. The number of part-time coaches varies depending on customer demand.
Once they are recruited, new coaches attend a one-day orientation training course delivered by a core team of certified teachers. During this training, coaches learn about Cell-Ed’s unique approach toward literacy and learning, and become familiar with the Cell-Ed platform, in order to serve learners. Additionally, coaches receive continuous technical support from Cell-Ed’s expert team. A weekly check-in is conducted via phone calls and emails where coaches discuss their work and raise any issues that require support and guidance. Coaches are also encouraged to reach out to the expert team in between check-ins with any questions or issues they may have.
Monitoring and Evaluation
The evaluation and assessment of learners’ progress is conducted through a computer-based Learning Management System (LMS) developed by Cell-Ed (See Figure 2 for the LMS below). The LMS makes it possible to gain comprehensive and useful data on the use of the Cell-Ed platform and the progress of each individual learner. Information on the platform includes: general information on learners (gender, age, and country), total number of learners, graduates, most repeated module, learners’ engagement in learning (time spent and mobile device used), SMS messages from learners, monthly frequency of calls from learners, percentage of learners who passed the final exam. Information on individual learners includes: time spent on the platform, completed courses, interaction with the live coach (content of SMS messages and number of phone calls), courses that the learner struggled with most, and the live coach’s assessment of the learner (both qualitative and quantitative). Through this system, the learning progress of individual learners can be measured by comparing the results of assessments taken by learners before and after each course. Cell-Ed monitors and evaluates its programme by analysing this LMS-generated information.
This system is also helpful for motivating learners and offering them personalized guidance. For instance, when they have made progress, learners immediately receive positive texts and emojis generated by the system. When individuals struggle, the system identifies these learners and helps them to understand grammatical points and concepts by sending them auto-texts. If a learner still faces difficulties, a Cell-Ed live coach follows up and provides one-to-one support via SMS or phone calls.
Upon successful completion of each level, learners receive individual certificates as a way to recognize and celebrate their efforts and achievements.
Programme Impact and Challenges
Impact and Achievements
Since 2014, Cell-Ed has reached more than 10,000 non-literate and low-literate adults in the USA, and by 2018 it will reach more than 20,000 learners outside the USA. To date, Cell-Ed has logged over 1 million minutes of teaching, with more than 800,000 text messages exchanged between learners and Cell-Ed.
The efficacy of Cell-Ed in literacy learning has been corroborated by the results of a competition organized by a market-leading assessment company for digital educational products. In a four-month trial period involving 1,000 learners, Cell-Ed received the highest overall score of 91 points, ahead of five main competitors; Cell-Ed also outperformed its competitors by an average of 20 percentage points in the engagement and user experience categories.
Because of its outstanding work and immense contribution toward adult literacy and education, Cell-Ed has gained recognition from many organisations and institutions, for example:
- Cell-Ed was awarded a Library of Congress Literacy Award in 2016.
- In May 2017, Cell-Ed’s New York State Programme received the Top 25 Innovations in American Government Award from the Ash Center for Democratic Governance and Innovation at Harvard University. This award highlighted Cell-Ed’s outstanding performance in providing English-language training via mobile phones to hundreds of immigrants in the state.
- In June 2017, Cell-Ed was named the Innovator Worth Watching by Harvard’s Clayton Christensen Institute for its potential as a disruptive innovator.
- In July 2017, Cell-Ed became a top-eight semi-finalist for the Adult Literacy XPRIZE, a global competition that culminates in 2019.
- In July 2017, Cell-Ed was highlighted by Digital Promise as one of three Powerful Edtech products for adult learners in improving access to learning.
- In November 2017, Cell-Ed was chosen as a finalist for the Global Ed Tech Startup Awards.
Beyond literacy skills, Cell-Ed has greatly empowered its learners in their private and professional lives, as reflected in the following testimonies from Cell-Ed learners and customers .
‘I liked that I didn’t have to sit in a classroom, but could study wherever I was, just calling again and continuing where I left off.’—Constantia, nursing assistant, New York
‘It’s very easy. I take my teacher with me anywhere and in my free time I turn it on and that’s it.’ —Reyna Fuller, homecare worker
‘I’ve seen lots of changes. I have more self-confidence and my children no longer have to go to the store with me to interpret.’ —Maribel Navarro, homecare worker
‘I was able to practise pronunciation over and over. Now I know I’m saying the words correctly.’—Carlos, construction worker, California
‘Now I recognize the numbers of the buses, what city they are coming from, where they are going, all of that. I feel more liberated because I can do it alone now and I do not need to have someone by my side, or ask someone passing by to do it for me.’ —Lucia, an immigrant from Peru
‘Before, when I had to call some office, they didn’t have someone speaking Spanish. But now I can do it in English.’ — Dilma Corea, nursing assistant
‘The custodians in our workplace English class love Cell-Ed… a learning device in their pocket and ownership of their learning.’ —Jon Engel, director, Texas Training Center
‘Cell-Ed is an innovative learning model that teaches members scenarios for professional life.’ —Syuzanna Petrosyan, SEIU
‘Cell-Ed empowers you, enables you to rise to the highest levels.’ —Governor Andrew Cuomo, State of New York
In this age of mobile technology, developers have more experience in creating programmes for smartphones. However, Cell-Ed must be accessible to learners with all types of basic phone, feature phone or smartphone. Therefore, developing a platform that is compatible with every phone can be a challenge for programme developers, who are often comfortable administering online learning and app-based mobile programs, but not text-based solutions.
Individual learners have varied demands. Sometimes it is challenging for Cell-Ed to develop new and additional courses that meet their vast range of special needs. Generally there is limited funding, both government and private, for adult and continuing education, and less emphasis is placed on non-formal adult education, especially for socially and economically marginalized populations. There has been a long-term bias against applying education technology development to learning programmes and content designed to meet the needs of low-literate and low-skilled populations.
As Cell-Ed expands its work with various customers and partners, it is clear that a high demand for essential skills training spans all industries. Thus, it is impossible to focus only on one industry, such as manufacturing, or just one learning area, such as literacy. Rather, Cell-Ed must be nimble and responsive to meet the various needs of different organizations and companies with the right content.
Cell-Ed has learned that working with customers who are learner-centred, share Cell-Ed’s values and goals, and are willing to work together to achieve those goals, helps to maintain funding sustainability and achieve better results. This enables both Cell-Ed and its customers to grow together, achieve common goals and mutually benefit.
To more effectively support potential customers, Cell-Ed has created an ‘onboarding’ package, for customers who use Cell-Ed as part of a blended training programme. This means customers are better equipped with the necessary information to use Cell-Ed. Moreover, the onboarding package can be an effective way to market Cell-Ed to potential customers.
Cell-Ed has begun analysing data more consistently to gauge the learning progress of learners and the impact of Cell-Ed over time. This information is then used to implement further improvements and to promote best practices.
To achieve financial sustainability for the future of this programme, Cell-Ed has approached several different investors and customers. There are already multiple interested partners for Cell-Ed, from local government and NGOs to the private sector. Achievements and recognitions received by Cell-Ed will bring more potential partners and investors to the programme.
The number of mobile phone users in the world is projected to increase every year. As more people gain access to cellular telephones and develop their technology skills, more and more adults will become Cell-Ed learners. Given their relative affordability and the ease of use, cell phones will continue to be the medium of instruction for Cell-Ed. The number of older adult learners using Cell-ED will increase given the programme’s high accessibility and simple design.
Expansion of Cell-Ed to Other Countries
Since 2017, Cell-Ed has been piloting its programme in countries such as Chile, Ghana, Kenya and Nigeria, in close collaboration with international development agencies, corporations or government organizations from these countries. These partnerships are designed to use Cell-Ed’s mobile learning course development model and Learner Management System to advance language, entry-level employment and essential skills, and to provide support to students and teachers in specific, targeted countries. Each partner addresses learners’ needs and further contributes to the quality and equity of learning through Cell-Ed’s approach. Together with in-country partners, relevant and contextualized courses are developed. Cell-Ed’s platform has started to add new languages to better support its in-country partners and their adult learners.
- Ash Center for Democratic Governance and Innovation. 2017. Ash Center Announces Finalists and Top 25 Programs for Innovations in American Government Award. [online] Available at: https://ash.harvard.edu/news/ash-center-announces-finalists-and-top-25-programs-innovations-american-government-award [Accessed 9 November 2017].
- Batalova, J. and Fix, M. 2015. Through an Immigrant Lens: PIAAC Assessment of the Competencies of Adults in the United States. [pdf] Available at: https://www.migrationpolicy.org/research/through-immigrant-lens-piaac-assessment-competencies-adults-united-states [Accessed 9 November 2017].
- Evans, D. 2014. Teach Literacy by Text Message. Really. [online] Available at: http://blogs.worldbank.org/impactevaluations/teach-literacy-text-message-really [Accessed 9 November 2017].
- Ksoll, C., Aker, J., Miller, D., Perez, K., and Smalley, S. 2014. Learning Without Teachers? Evidence from a Randomized Experiment of a Mobile Phone-Based Adult Education Program in Los Angeles. [pdf] Available at: https://www.cgdev.org/sites/default/files/CellEd%20Paper_22july2014.pdf [Accessed 9 November 2017].
- Migration Policy Institute. 2017. Frequently Requested Statistics on Immigrants and Immigration in the United States. [online] Available at: http://www.migrationpolicy.org/article/frequently-requested-statistics-immigrants-and-immigration-united-states [Accessed 9 November 2017].
- OECD. 2016. Skills Matter: Further Results from the Survey of Adult Skills. [pdf] Available at: http://www.oecd-ilibrary.org/education/skills-matter_9789264258051-en [Accessed 27 September 2017].
- Statista, 2017. Number of mobile phone users in the U.S. from 2012 to 2020 (in millions). [online] Available at: https://www.statista.com/statistics/222306/forecast-of-smartphone-users-in-the-us/ [Accessed 9 November 2017].