The sample of the present study consists of 38 children with DS (specifically, with trisomy 21), of whom 22 were boys and 16 were girls (M = 5.2 years, SD = 1.05); 20 were in the experimental group and 18 in the control group (Table 1). All the children were enrolled in regular public centers since they were 3 years old. None had any additional health problems or suspicion of dual pathology (e.g., possible additional diagnosis of autism) according to reports from the Early Childhood Development Center (ECDC), where they were treated from birth. In Spain, all newborns identified by the pediatrician are referred to the Early Childhood Development Center (ECDC) closest to their home by national health protocol (Robles-Bello & Sánchez-Teruel, 2013; Robles-Bello et al., 2018).

Therefore, the criterion for assigning each method was that no reading method was initiated, so in the experimental group a reading method was initiated and in the control group it was initiated 9 months later.

The children in the experimental group (EG) came from Down syndrome association centers and ECDC in Jaén, Ciudad Real, Córdoba, and Andújar. Children in the control group (CG) were from two centers in Linares and one in Úbeda.

Early child care programs are drawn up at all the centers. Centers were then asked for permission to conduct this study, permission that was also sought from families. In all the centers, except for two in Linares and one in Úbeda, the pretest situation is evaluated first and immediately afterwards the interventions which are carried out for between four to five years. The training program application (Troncoso & del Cerro, 2005) takes place once a week for one year and includes coordinating and working in conjunction with schools and families. All these children belong to the experimental group.

However, although the centers in Linares and Úbeda are evaluated at the pretest level, intervention is not carried out there because these centers usually start this method a little later, around the age of five. The situation regarding age is used to create a control or waiting group, as they will eventually receive treatment nine months later. Finally, all the children are reassessed in a posttest situation. The control group will be evaluated first in order not to delay the start of their own reading training program.

This work was approved by the bioethics committee of the University of Jaén (code: DIC.18/0.PRY).

Weschsler Intelligence Scale for Preschool and Primary School (WPPSI; Spanish adaptation, Escala de Inteligencia de Wechsler - WPPSI-IV, for pre-school and primary education; Weschsler, 2014) is a battery consisting of several subtest measures of qualitative and quantitative aspects of general intelligence. WPPSI, like WISC, is divided into two parts: verbal and manipulative. The subtests that assess verbal intelligence are: Information, Vocabulary, Arithmetic, Similarities, Comprehension, and Sentences (complementary). The subtests that evaluate manipulative intelligence are: House of the Animals, Incomplete Figures, Labyrinths, Geometric Drawing, and Squares. Its administration is individual and is normed for children 2.6 to 7.7 years old. Test administration usually takes 60 to 90 minutes. Test reliability varies, depending on the subtest and the age group; for 5 to 5.5 year-old children reliability coefficients range from .93 (verbal and manipulative CI) to .95 (total CI scale).

Childhood Neuropsychological Maturity Questionnaire (CUMANIN; Portellano et al., 2002) is an individually administered test for the evaluation of children aged 3 to 6 years (36 months to 78 months). Test taking varies (generally from 30 to 50 minutes). CUMANIN contains main scales (psychomotricity, articulatory language, comprehensive language, expressive language, spatial structuring, visuoperception, iconic memory, and rhythm) and auxiliary scales (attention, verbal fluency, reading, writing, and laterality). The level of reliability alpha varies depending on the scale: .71 (psychomotor), .92 (articulatory language), .73 (expressive language), .72 (comprehensive language), .81 (spatial structuring), .91 (visoperception), .57 (iconic memory), and .72 (rhythm).

Navarra-Revised Oral Language Test (PLON-R; Aguinaga et al., 2004) is an individual administration test for rapid identification or screening of oral language development. It is normed for 3 to 6 year-old children. Test taking is variable, ranging from 10 to 12 minutes. PLON-R consists of several linguistic levels: phonological, morphological, syntactic, lexical, semantic, and communicative use. The reliability coefficients in 5 year-old children are: .91 (phonology), .43 (morphology-syntax), .87 (form), .54 (content), .13 (use), and .76 (total PLON-R).

The use of Troncoso and del Cerro’s (2005) reading method is widely disseminated and accepted among the group of children with DS who attend associations that serve this group and ECDC centers. For this reason, the first thing we check is that this reading method was used in these centers within their work program.

The number of evaluation sessions was between 3 and 4 sessions for each participant (pre- and post-evaluation) with a variable duration depending on the test administered, ranging from 15 to 90 minutes. It was administered individually and in different sessions in a balanced way: first WPPSI, followed by CUMANIN, and finally PLON-R.

The evaluation sessions in both groups were conducted by the first two researchers of this study, with biweekly follow-up sessions, for the intervention program, with the psychologists who administered the training program in each center on a regular basis, and monthly with the families by video call.

Intervention program. The program for teaching reading and writing in Down syndrome (Troncoso & del Cerro, 2005) is a method of reading and writing for students with DS. It is a comprehensive and analytical method that describes the sequence to be followed, and the errors to be avoided, in the teaching-learning process of reading and writing. It consists of multiple examples and illustrations in an attempt to help parents and professionals during this process. The method is structured and explained, taking into account the ideal situation (i.e., that of a 3 to 5 year-old child who has participated in an early care program in which he/she has progressed adequately in his/her perceptive and manipulative faculties). However, if the student is older, the activities and materials appropriate to their level of maturity and skills will be derived. The program is divided into three stages of teaching and learning (for both reading and writing), each of which has its respective specific objectives and related materials.

The intervention phase is applied only to the experimental group. Initially a pre-workout evaluation is performed. Alongside these evaluation sessions it is noted, with interviews with the teaching psychologists who attend to these children, that the methodology of this intervention program is being followed. Two aspects are checked with them. On the one hand, that it is important to work the motivation of the child as well, since it is much easier to get their attention on a simple word and rich in content than on a sign in principle unintelligible. On the other hand, all children, who are cared for in ECDC centers, are undergoing an educational process and training their perceptual and discriminatory abilities. Before starting reading, they have been training attention, perception, and discrimination (skills to associate, select, classify, name, and generalize) and manual dexterity, as directed by the method. This whole process takes about three months from the end of 2017.

In January 2018 the intervention began, continuing throughout the year, with the exception of August. The reading method comprises three different stages with specific objectives and provides its own materials for each of them. At the same time, the three stages are interrelated and sometimes objectives must be reached simultaneously. This is mainly because the conditions of understanding, fluency, and motivation must be kept and consolidated at any time in the process. It is not necessary to complete all the goals of one stage before starting to work on the next.

The first stage is global perception, recognition of written words, and understanding their meaning. The important thing at this stage is for the student to understand what reading is, that is, how you access meanings and messages through graphic symbols. This stage starts with isolated words and soon phrases are presented. This recognition must occur whether the words are presented in isolation one at a time or presented in a phrase. There are specific goals for the student, including recognizing his or her written name and that of four or five members of their family and recognizing and understanding the meaning of 15 to 20 written words consisting of two direct syllables. Words should include two or three verbs of action known to the child, written in the third person singular in the present tense. A further goal is that the child recognizes 50 to 60 words including the above. Most words will consist of two direct syllables and some of them with three syllables. Words must include five verbs in the first and third person singular of the present tense and some adjectives. The number of words in indicative should not be taken as a hard and fast rule, and the amount of words is gradually increasing.

In order to choose the words the child must learn and add some new ones, we take into account the idea that each word must have a clear meaning known to the child. This usually happens with the names of next of kin and those of commonly used objects, which they know and use on a daily basis in real life. The child has often heard the words used to name them. They do not have to know how to say them. Words are selected that can be clearly represented graphically. Short words will be chosen, and when 30 to 40 words are recognized it is advisable to choose those words that start with letters of the alphabet that have not yet been seen in the initial position of the words. In order to coordinate and consolidate learning, words can be chosen that include concepts (size, shape, and colors), adjectives, and others that can be classified by categories (food, toys, animals, etc.). Finally, another criterion used is the choice of new words that increase a child’s vocabulary.

In the second stage, we work on learning syllables. The fundamental objective is for the student to understand that there is a code that allows us to access any written word not previously learned. When we master the code we can read all the texts written in our language, even if we do not know the meaning of some words. The general objective is for the student to read fluently and flexibly words formed by any syllable, and immediately understand their meaning. To achieve this, the specific objectives are that the student observes that the words are formed of syllables, in order to compose with a model words known of 2 direct syllables; in order to compose without a model, words known with 2 direct syllables that are presented to him recognize and read the 2 syllables used to form a word; in order to compose with 2 known syllables, unrecognized words of meaning, quickly recognize and read all direct 2-letter syllables, form words that are dictated to them or that they think have been dictated, choosing the direct syllables needed, read without syllables, understanding previously unrecognized words, which are made up of direct syllables; in order to compose with model, words that have a locked syllable, recognize and read locked syllables, compose words of 2 syllables without a model, one of them locked, fluently read words of 2 syllables, one of them locked; in other to compose with model, words containing 1 reverse syllable, recognize and read reverse syllables; in order to compose, without a model, words containing reverse syllables, model compose words with 1 consonant group and 1 direct syllable, recognize and read the consonant groups, and finally read words containing consonant groups fluently.

Once the student has understood what reading is and gets to know the reading mechanics, the third stage is carried out, that of progress in reading.

In the third stage, the ultimate goal is to get students to read progressively more complex texts and to allow them to make practical and functional use of their reading skills, to see reading as a pleasurable activity, which provides information and allows them to spend their time enjoyably and finally that reading is a tool with which to learn other academic content.

In December of the same year it is reassessed, ending in January 2019.

An intersubjetct design of the quasi-experimental type (Ato et al., 2013) was followed. The data analysis was performed with IBM SPSS Statistics Base software (Version 23.0.0) licensed from the University of Jaén (IBM Corp., 2015; Palant, 2007; Mooi & Sarstedt).

Both groups were equivalent in sex and age; participants were assigned in nonrandom fashion. Due to the size of the sample, nonparametric measures were used; specifically, the Wilcoxon test was applied to contrast differences in the CUMANIN, WPPSI, and PLON-R scores in the pre- and post-phases. The effect size was measured using the criterion of Cohen’s index (see Ato et al., 2013). In order to know which variables predicted reading abilities in the participant groups, a multiple regression analysis was applied using the step-by-step procedure (i.e., finding the goodness-of-fit indices first and subsequently assessing whether the model was adapted to the forecasts initially proposed according to the initial hypothesis).

Despite our findings, there is a limitation in that we cannot make an exhaustive evaluation of the reading in a personalized way (as was done by Lemons et al., 2018); this would be interesting as a next line of future work. In consequence, while the reading program seemed to improve general learning for many children with DS, it is not clear whether a greater adaptation or individualization of the intervention could lead to further improvement. Further, we would still face challenges in evaluating this population’s reading abilities, given that there are no tests that measure reading specifically at these ages and or that are suitably adapted to persons with intellectual disabilities.

We conclude that the CG children significantly improved in psychomotricity, comprehensive language, spatial structuring, and iconic memory. According to the results obtained, this program can work to promote success in early childhood education and prepare children for access to the educational curriculum. The EG, in contrast to the CG, significantly improved in all the variables when being evaluated neuropsychologically and they also improved specifically in reading and writing (especially in reading). Two variables in the study (rhythm and attention) predicted reading in this sample and helps us understand what aspects are important to develop from a very early age. Our findings provide support for the incorporation of phonological awareness and phonics-based instruction in reading for children with DS.