with different communication disabilities. AAC refers to different forms of communication methods that persons with complex communication needs (CCN) are using to express themselves which enables them to equally participate in everyday life. Common causes of CCN are severe intellectual disability, cerebral palsy, autism, childhood apraxia of speech, traumatic brain injury, stroke and degenerative diseases etc. and they result as significant speech, language, motor and/or cognitive impairments. Persons with CCN are diverse group ranging from young people to very old, with different diagnoses, life experiences, abilities and preferences and they are unable to communicate or to participate independently in society. Some persons require AAC technologies for a short time only, while others need communication technologies throughout their lives. We live in the world of pervasive information and communication technology (ICT) where ICT services are continuously and rapidly changing the way we live. Almost every aspect of life has become connected and available from different devices. For a large part of the population ICTs and ICT services are difficult to use, sometime even fully unusable. Beside mentioned persons with CCN there are groups of persons with different disabilities (permanent or temporary nature) and older people with age-related changes in functional capacities that are unable to use common ICT services and/or products or they experience significant difficulties while accessing and using them. Term e-Accessibility concerns the design of ICT services and products so that they can be accessed and used by people with different disabilities. The importance of accessibility to information and communication is also recognized and stated in UN Convention of the Rights of Persons with Disabilities. e-Inclusion initiative aims to achieve equal opportunities to all people when it comes to using ICT services and products and equal opportunity to participate in the society according to their abilities. This dissertation contribution, information and communication service platform for AAC, re- presents modern technology based enabler for both e-Accessibility and e-Inclusion aspirations. Presented platform should not be considered as a solution for AAC problems rather as the piece of the puzzle of a general solution finder. This dissertation presents several studies with their results that were carried out to develop unique information and communication platform for alternative and augmentative communication. Platform and platform components are thoroughly described in following sections. First chapter of this thesis gives the introductory information about research subject, goals and hypothesis. Research motivation is explained through initiatives such as e-Inclusion and e- Accessibility and their contribution to society. Second chapter investigates augmentative and alternative communication (AAC) as a communication method that helps persons with complex communication needs (CCN). Symbols as an essential part of AAC are defined and divided into different groups based on their type (visual, acoustic, tactile and symbols expressed by the movement of the body) and an overview of different symbol galleries is presented with their basic characteristics. In this research, focus was on ICT services for symbol based communication and a detailed list of available ICT-AAC services is given. While studying available ICT services for AAC we focused on their ability to adapt to different users and their preferences as well as the ease of their use. Research has shown that general ICT services most often are not suitable for users with CCN and that services’ graphical user interfaces (GUI) are usually not adjustable for different users’ abilities. To achieve goals stated in initiatives e-Inclusion and e-Accessibility, ICT services should be adjustable to different users’ abilities and preferences. Third chapter describes extensive research on accessibility of web pages and web content ove- rall. Web pages are considered the most widespread form of ICT service and accessibility level of ICT services available through Internet web pages has a great impact on inclusion of per- sons with CCN. Accessibility was measured based on W3C organization defined guidelines (Web content accessibility guidelines, WCAG) that are de facto standard for web accessibility. WCAG guidelines, grouped by their priority level (groups A, AA and AAA), are described with practical examples. List of different tools for WCAG accessibility check that were tested in order to find suitable tool for large scale testing is given with their specifications. For this research, a 1000 web sites contained in catalogue WWW.HR were selected randomly and tested with tool developed especially within this research. Architecture of developed tool is given along with testing process flow. Accessibility check was performed in two separate iterations (July 2012. and August 2014.) and results are shown for every iteration for all guidelines priority levels. While processing results guidelines that were most often unsatisfied have been extracted to evaluate automatic accessibility process. In fourth chapter web page accessibility is considered as a system availability measure. Since every WCAG guidelines deviation can cause a access barrier to some group of users we considered that exception as an system failure (system is not working properly in that time period). Model for including accessibility in common calculation of system availability is proposed to emphasize accessibility importance. Fifth chapter brings further study of web accessibility with focus on achieving accessibility by processing web content. Based on results obtained in accessibility research of 1000 web sites and highlighted most unsatisfied guidelines this study is evaluating possibilities of automatic web content adjustments to create accessible and WCAG guidelines compliant web page. Re- search starts with general web page structure and component analysis which revealed that there are only few irreplaceable web page elements considered as main parts. These main parts are responsible for page content and by adjusting them accessibility level can be increased. Beside web page elements definition, a study of web page elements processing was carried out and automatic web accessibility adjustment process is proposed. Proposed process is formed of two sub processes: web element classification and classified element adjustment. Web element classification study was carried out and current state of the art methods were examined. Based on this study a Naive Bayes classifier with supervised learning process was selected and described in more detail. Adjustment process of classified element is proposed and described. Process of automatic web elements adjustment implementation is described in chapter six. Both sub processes, elements classification and classified elements adjustment, implementation is described in more detail as well as developed system architecture. For supervised learning pro- cess a tool for manual element classification has been developed for gathering labeled training data. Based on that training data, implemented classifier has been instructed to assign one class to new examples. Verification of implemented process was performed with the same accessibility check sys- tem described in chapter three. Results of accessibility analysis for automatically adjusted web elements is given. Implemented automatic web elements adjustment process, described in chapter six, was put into operation in ambient assisted living (AAL) environment. In chapter seven ICT system for AAL environment, developed within this research is described. System is intended for accessing news portals and consuming content in different formats (original format, plain text format or voice representation of content obtained with text-to-speech synthesis). Intention of this research was to evaluate automatic content adjustment and/or transformation. Evaluation was performed with three groups of people. Each group consumed content in different format followed by two different questionnaires. First questionnaire contained content relevant questions and second questionnaire contained questions on users’ experience while interacting with system. While users were answering first questionnaire, time was measured to evaluate which format was best appropriate. Questionnaires’ answers were processed and results are given. Chapter eight deals with accessibility of ICT services available as mobile device applications. In chapter two we concluded that web pages are the most widespread ICT systems since most of ICT systems are available through web pages. Another access point to ICT services, equally common are mobile device applications. Chapter eight presents three different mobile application architecture based on technology they built of (native applications, hybrid applications and web applications for mobile devices) and possibilities to achieve accessible mobile applications along with guidelines for creating accessible mobile applications. Dealing with accessibility level of ICT service usually means adjusting services’ user interface (UI) functionalities and appearance. Standard peripheral devices (keyboard, mouse etc.) along with GUI are every services’ point of contact with users and they can be point of failure if they are not accessible. UI is the only user interaction point in case of pervasive touch screen devices so it is very important to have accessible GUI. Except accessibility UI should be adjustable to every user’s abilities and preferences and that adjustment should follow user’s abilities changes. In chapter nine model of UI for AAC service is proposed. Proposed UI represents developed ICT-AAC platform component for creating ICT AAC services with UI that can evaluate user’s capabilities and adjust accordingly. A study of ICT AAC services was carried out and results revealed that there are two types of AAC users: CCN persons that are using AAC to communicate and CCN persons personal assistants that are using AAC methods to communicate with CCN persons. Both group of users are using same ICT AAC services and since personal assistants have more abilities (usually they are non-CCN persons) than regular user with CCN, services’ UI should be changed to match every user’s abilities. Changing UI appearance to achieve better user experience and to increase usability is called the user interface adaptation. Adaptation can be manual (e.g. when user increases font size or changes background colour) or automated (e.g. adjusted web site appearance on different device such as mobile device or tablet). Automated adaptation, presented in this chapter supports initial adaptation (upon first usage of service) and continuous ongoing adaptation process during using the service. Proposed UI model along with adaptation process is implemented as AAC mobile application described in this chapter. In symbol based communication, such as AAC, there are large number of symbols that can be used. Symbol galleries usually have more than ten thousand symbols depicted in different styles and sizes. In common communication user uses only small subset of symbols, the ones he/she is familiar with. This is similar to spoken or written communication where we use words from our vocabulary that represents only small subset of all words that language contains. ICT AAC services should provide available gallery symbols which is not practical. Transferring large amount of images consumes network traffic as well as device storage and it should be optimized. Tenth chapter describes proposed cache and prefetch model for AAC communication where based on users’ knowledge only relevant symbols are fetched. Model was designed based on study of learning materials for users with CCN. In the final two chapters, information and communication service platform for AAC is described. Platform enables component-based development of new AAC services based on pre developed components. Developed components can be combined with new ones to create new AAC service with adjustable UI and accessible content with automatic adaptation to user’s abilities. In this thesis, information and communication service platform for AAC is proposed with series of proposed processes and models that are necessary to accomplish platform for component- based development of AAC services with functionalities to adjust based on user’s abilities.