Complex communication needs can arise from a number of acquired or congenital impairments and manifest themselves as a series of intellectual, motor, socio-cognitive and verbal difficulties. Persons with complex communication needs are not able to communicate in an ordinary fashion (through speech). They use mostly symbol-based augmentative and alternative communication (AAC) to express their thoughts, needs, wishes and ideas. A classic approach to teaching cannot be applied to this extremely diverse and heterogeneous group of persons. Instead, a creative, structured and individualized approach is required. Educational information-communication services can complement existing methods of teaching persons with complex communication needs, such as the highly-efficient and scientifically established Applied Behavior Analysis (ABA) and Discrete Trial Training (DTT). Every educational ICT service for this user group must be adapted to an individual user to the maximum extent. For this purpose, a model for assessing the success of mastering educational content based on Discrete Trial Training is proposed. The proposed model is implemented within an educational ICT application for teaching receptive labeling to persons with complex communication needs. After initial user testing, the model and the educational application are expanded with dynamic adaptation of educational content. The implementation of the proposed model, along with the mechanism for dynamic adaptation, within an educational ICT application can help young special education teachers, parents and care-givers not familiar with Discrete Trial Training. Expert special education teacher also benefit because it deprives them of the need to constantly keep track of the educational session, write down progress information or spend time preparing educational material. Instead, they can focus completely on the person they are teaching. The developed mechanism for dynamic adaptation of educational content is evaluated on a selected group of children with complex communication needs (children with autism spectrum disorder and various levels of intellectual difficulties). The goal of this evaluation is to show the applicability and contribution of conducting an educational session using an educational ICT application with dynamic adaptation of educational content on a touch-screen device as opposed to conducting an educational session in the traditional manner. Another goal of the evaluation is to show the efficacy of the proposed dynamic adaptation of educational content, implemented within the educational ICT application. An existing Platform for developing augmentative and alternative communication services is expanded with an educational module that represents a foundation for the development of educational ICT services for persons with complex communication needs. By creating a reusable teaching model and adapting the described educational ICT application to work within the Platform, the interoperability problem of educational ICT services for augmentative and alternative communication users is solved. The use of symbols constitute the basis of augmentative and alternative communication. While several non-commercial symbol galleries can be found on the Internet, it is important that an AAC user has quick access to symbols he/she is familiar with in order to communicate more efficiently. This problem can be solved by enabling the AAC user to create a customized personal symbol gallery that would contain a categorized set of symbols he/she comprehends. With this in mind, a procedure for the selection and personalization of symbols for augmentative and alternative communication is defined and implemented as a case study within the Platform. The procedure is verified on a symbol prediction during AAC case study as an example of a practical application of the described procedure. The introduction gives an overview of current research along with the goal and scientific contribution of conducted doctoral research. This chapter also describes the role of information and communication technology in the domain of augmentative and alternative communication for persons with complex communication needs. The second chapter describes the problems the thesis solves along with the motivation. This chapter also describes the scientifically verified method for teaching persons with complex communication needs upon which the proposed model for assessing the success of mastering educational content and the mechanism for dynamic adaptation of educational content are based. Existing educational software solutions related to the research domain are listed and described. The third chapter describes the proposed model model for assessing the success of mastering educational content based on Applied Behavior Analysis and Discrete Trial Training which constitute a recognized and widely applied method for teaching persons with complex communication needs. The chapter also describes the implementation of the proposed model within an educational ICT service on a touch-screen device and its application in several educational sessions with special education teachers and children with complex communication needs in order to verify the applicability of the proposed model and the applicability of conducting an educational session in the form of an educational service on a touch-screen device. The fourth chapter describes the mechanism for dynamic adaptation of educational content for users of ICT based augmentative and alternative communication. The mechanism is implemented within the educational service case study and evaluated on a group of end users in several educational sessions. The results of this evaluation are analyzed in order to determine the efficacy of conducting an educational session in the form of an educational service on a touch-screen device and also to assess the dynamic educational content adaptation mechanism and optionally define improvements. The fifth chapter gives a formal description of the procedure for the selection and personalization of symbols for augmentative and alternative communication for personal use. The procedure is implemented within the Platform and verified on a symbol prediction case study. The sixth chapter describes the expansion of the Platform for developing augmentative and alternative communication services with an educational module and the adaptation of services described earlier for work within the Platform. The advantages and disadvantages of developing educational services for AAC users within the Platform are analyzed. Conclusions drawn from the thesis and suggestions for further research are given in the seventh chapter.