A reading and language intervention programme trialled in an isolated Chilean population. These data are derived from a randomised controlled trial study that evaluated the effects of a reading and language intervention, for low-income children living in Chile. Participants came from a population previously identified as having a high incidence of language disorders and were aged 4 to 14 years (Male n=34, Female n=34). Intervention groups were allocated by minimising on a language and age. Children in the intervention group received a 27-week programme aimed to foster word reading and oral language skills. Data are provided for age, school grade and gender as well as measures of phonological ability (letter knowledge, phonemic awareness, nonword reading), reading skills (word reading, reading comprehension, spelling), vocabulary (picture word matching, taught vocabulary, expressive vocabulary, receptive vocabulary), listening comprehension, narrative and IQ. Data are available for four time points; t1 (baseline), t2 (14 weeks into intervention), t3 (post intervention) and t4 (9 months after intervention).The Robinson Crusoe Island is a remote island situated 667km west of Chile. It forms part of the Juan Fernandez archipelago in which there are three Islands but this is the only inhabited one. Access to the Robinson Crusoe Island is difficult, there is aeroplane access in the summer but in the winter there is only a monthly ship which serves the island (if possible). This means that the Islanders are very isolated, both geographically and culturally from the mainland, even though they are Chilean. The current population of the Island is approximately 800 people. The majority of these people are descendants of the families that founded the Island in the late 19th century and most people earn a living from lobster fishing. All people live in a single town and all children attend a single school. Although the school follows the curriculum of the mainland, the teachers usually come from the mainland on a 2-3 year post and so are not necessarily integrated into island culture and the teaching tools are not always modified to the Islanders and their way of life. The isolation of the island means that children have to move to the mainland at a young age if they wish to continue their studies into higher education. Travel to the mainland is also essential for medical and dental treatment meaning that children can miss a lot of school. These factors can act as a barrier to a high quality education and reflect the challenges faced by many isolated and indigenous communities through Chile and the world. The vulnerability of the Robinson Crusoe population, in terms of educational opportunities, is further increased by a high incidence of language and learning disorders, which are associated with lower educational attainment and employment opportunities. In addition, a tsunami recently struck the island wiping out existing municipal facilities including the school. Classes now take place in a shipping container with little space for individual tutoring or quiet lessons. In the UK, studies have shown that vulnerable populations can be helped by extra lessons at school. Training in speech-sounds, letter knowledge and reading provide the best long-term educational advantages for children with language difficulties. Strong language foundations, in turn, bolster literacy development and numeracy skills and provide a wider framework for classroom learning. We would like to pilot this kind of scheme on the Robinson Crusoe Island to see if such interventions are also advantageous in isolated Chilean populations. This is an ideal population to test out the system because they have many complicating factors that challenge educational progression. If the interventions work here, we would like to make recommendations to extend the programme to other isolated, indigenous and rural populations in Chile. We will work with speech and language experts at the University of Chile, who have existing contacts with the Islanders and with specialists at the University of Oxford who have designed and trialled interventions in the UK and Brazil. We will work with local professionals to provide training and support of the programme transferring skills across international boundaries and building research capacities in Chile. We hope that the lessons learned from this project can be extended to indigenous and continental populations on the mainland and beyond, allowing Chile to take a leadership role in the confrontation of educational inequalities.

We conducted a randomised-control trial, with a cross-over design, in accordance with the CONSORT guidelines (Schulz, Altman, & Moher, 2010) (Figure 1). Sixty-eight participants were allocated to experimental (n= 34) or waiting control groups (n =34) minimizing for age and composite language scores (CELF-4 vocabulary and recalling sentences; Semel, Wiig, Secord, & Langdon, 2006). Group allocation was conducted independently by the York Trials Unit. Children were assessed before the start of intervention for pre-test (t1), after 14 weeks of intervention for mid-test (t2), immediately following the intervention for post-test (t3), and 9 months after the intervention finished for the intervention group (t4), which was also week 20 of intervention for the waiting group. Assessors were blind to group allocation at t1 (pre-test) and t3 (post-test), and trained in test administration and scoring. Measures of reading and vocabulary formed the primary outcome measures while measures of narrative and reading comprehension represented secondary outcomes. All data were collected in Spanish by Chilean natives. See the read me file for details of individual tests.