The seminal paper by Graves and Corcoran [10] in 1989 set the stage for conceptualizing the specialty of nursing informatics. They defined nursing informatics as "a combination of computer science, information science and nursing science designed to assist in the management and processing of nursing data, information and knowledge to support the practice of nursing and the delivery of care". Here they draw attention to the information of nursing, elaborating data, information, and knowledge as the foundational components for collection, processing, or manipulation by technological tools. Although there are different perspectives on the relations between data, information, and knowledge (i.e., portraying linear, progressing complexity or as mutually constituted, accumulated elements), the components can be understood as follows. Data is "raw facts," that is, the basic elements (atomic structure) or uninterpreted building blocks for composition to information or knowledge. Information is combined or structured data interpreted in different contexts or situations. Knowledge is data or information synthesized by formulas, heuristic strategies, or formally delineated relationships [8,10]. These interrelated elements of data, information, and knowledge point out important attributes of evidence in nursing, but they also differentiate foci within nursing informatics. The establishment of comprehensive nursing vocabularies with interface and reference properties, e.g., enumerative classification systems, combinatorial terminologies, or reference terminologies is an example of the important efforts to articulate, represent, and sort nursing data [11,12]. Combining data into a structure gives the meaning and value of these raw facts and basic expressions. Therefore, the structuring of nursing documentation and the developing of care protocols, care maps, or clinical pathways are examples of organizing, filtering, interpreting, and clarifying nursing information [13-15]. Examples of efforts to outline nursing knowledge include modeling the expert nurse's decision-making to provide computerized decision support to enhance clinical judgment [7] or elaborating on the knowledge resources at play to construct standards, common guidelines, and procedures [16]. Development of and access to information and knowledge are core requisites for supporting experiential and evidence-based decision-making, continuity of care, and patient safety. In sum, considerable achievements have been gained in terms of expressions for nursing assessment, nursing judgments, nursing interventions, and patient outcomes that are sensitive to nursing care. Substantial resources in informatics are currently committed to establishing comprehensive and formalized terminologies to represent clinical practice and standards for information exchange. This allows relationships among various types of data to be examined or transformed through more automated processes. This examination and transformation is surrounded with unresolved challenges due to the situated nature of patient care, the variation in personal health needs, and evolving opportunities resulting from new achievements and new tools.

Over time, scholars have suggested, discussed, and added functional elements that contribute to the collective effort to elaborate and expand the understanding, concepts, tools, and structures available to nursing informatics and nursing. These ideas include enhancing the patient's role, emphasizing the nurse's role as information integrator, developing sound collaborative relationships between providers or between providers, technologies, and specific contexts of decision-making, and including true interdisciplinary issues for patient safety and evidence-based practice [9]. A significant addition to the conceptual understanding of nursing informatics came more recently when Matney et al. [17] suggested the inclusion of wisdom, complementing the foundational concepts of data, information, and knowledge. Wisdom is understood as the "appropriate use of knowledge to manage and solve human problems" [17]. This is of great significance, important in understanding the variations in clinical processes in sufficient detail and in acknowledging previous experiences. In reality, Matney et al. [17] challenge us to acknowledge the situatedness embedded in nurses work, and to embrace accumulated clinical expertise. These are resources for skillful, competent clinical judgment, and they involve the contextual and intertwined nature of data, information, and knowledge.

Achievements in nursing informatics have inspired the systematization and formalization of information where data, structured information, and articulated knowledge are important building blocks for the development of IT-based applications. Most attention and in-depth study has been directed to describing information used in clinicians' judgments and modeling prototype applications for management that are decision-supportive. The studies also strive to provide the best evidence at the point of care to improve decision-making. So far, feasible practice models giving new tools for information handling have received little attention, and reported studies are often examples of workflow failure [18] or unintended consequences [19].

When we zoom in on applications using achievements in health informatics, there is also a plethora of tools, devices, and applications aiming to support the management of data, information, and knowledge related to health and wellbeing. The following types of applications add new opportunities and challenges to the field:

These types of applications present novel opportunities and important challenges to our field, but their interrelationships and how together they may contribute to efficient information are not fully understood [20-22].

The Problem-Oriented Medical Record [23,24] was among the first influential published implementation experiences where informatics supported health information management and health care processes. The core idea was to embed an information model that de facto restructured clinical documentation in the EHR, using a problem-oriented approach in an attempt to reengineer documentation processes. The systematization of information elements, charted according to predefined templates or as narrative texts, most often follows the problem-oriented information model rather than models that deal with body systems, basic needs, or functional status, to represent nursing practice in an EHR. The "stickiness" of the problem-oriented structure for information models is seen globally, reflected as the information model in the globally diffused nursing process, suggesting structures for clinical documentation of nursing care [13]. The same information model is seen as a dimension of nurses' work currently supported by emerging nursing vocabularies [11] and as the commonly used structure for health care knowledge representations, as a resource for the design, implementation, and evaluation of health information systems, and as an inspiration for practice changes following the deployment of health information systems [25].

Core features of nurses' work are teamwork, collaboration, and mobility. Nurses meet and interact with patients and their families in a variety of settings to contribute to prevention, early intervention, maintenance, or problem solving. Nurses typically care for many patients, and in a team, they assume key roles in coordinating patient care and treatment in collaboration with other providers [26]. Nurses collect a lot of data, and they access evidence at the nurses' station, at the bedside, in a person's home, or in an office. Incorporating contextual and environmental cues is crucial. These elements exemplify specific features of nurses' work and of their workflow. Lack of appropriate access to evidence at the point of need is a challenge for continuity of care and patient safety. Lack of aggregate information for reporting and benchmarking has so far been detrimental to nurses' adoption of new technological tools.

Professional collaboration can be supported by access to and/or contribution to the accumulating body of a person's specific health information in the EHRs. The EHR offers an interesting collection of quantitative data (e.g., vital signs or lab values), qualitative data (e.g., patient narratives or evaluation of care efforts), and transactional data (e.g., performed tests or delivered medications) [27]. More recent analytic techniques and approaches to the analysis of large amounts of data, or "Big Data," open up new ways of providing evidence to support knowledge development, decision-making, and interdisciplinary collaboration. Using information in the EHR means that the aggregation of authentic, real-time patient data offers opportunities for early intervention to prevent health problems or to manage existing conditions [28]. There are still unresolved issues of a professional, legal, and ethical nature with the new approaches to knowledge generation and to more information sharing within and across settings and levels of care [29].

As more health care activities migrate from hospitals to community care, the plethora of tools and functionalities follows. More work is needed to understand how better to integrate this information into the existing informatics infrastructure and into clinicians' suit of tools. Exciting opportunities for active collaboration with the patient and his or her family can be further developed through skillful use of EHRs in combination with the PHR. A PHR contains information chosen, collected, and maintained primarily by the patient or a trusted family member. We know that people make tradeoffs between types of health information and health concerns as they use sophisticated and robust health information management strategies [30]. Therefore, information kept in the PHR will vary with the health concern and interest of the person keeping it.

A PHR can be a stand-alone application set up and maintained at the discretion of the person keeping it. More common is some connection to organized health care services. Depending on institutional and organizational arrangements and provision of services, persons using such a PHR can access parts of their EHR securely and remotely, some can take advantage of secure mail for online interactions with the health providers as well for accessing relevant health information [20,31]. In addition, the PHR carries the potential to be an even more used and valued resource for accumulating health information and supporting health information management as care activities increasingly shift to focus on prevention and early intervention and actively include the extensive self-care efforts of the citizens themselves. As such, a PHR can be an important resource for nurses if the recipients of nursing care choose to grant access to their caregivers. To be even more valuable for multiple users and uses, practical ways of capitalizing on benefits from the explication, systematization, and formalization of data, information, and knowledge can help us move forward. We believe that attention to wisdom and acknowledgment of the situational dimensions and specifics in nurses' interactions with their patients will open up new beneficial, collaborative relationships and further achievements.

New areas of application of health informatics can be found in the use of the growing suite of tools for ambient assisted living and smart houses and in the new potentialities for generating practice-based evidence using "Big Data" analytic techniques. New tools are increasingly used for personal monitoring and self-care activities, and we see expanding opportunities in applications labeled under the umbrella of mHealth or uHealth. These applications range from support for collecting personal observations, e.g., vital signs and observations of daily living [32], to support in collecting data from passive, environmental monitoring, e.g., use of space [33] or global positioning system for outside positioning [34], to the use of available tools to maintain independent living, e.g., tablets and smartphones for information access and new modes of participation [35]. These are novel opportunities to support the individual's personal health information management and safety requirements to allow him or her to remain at the preferred home dwelling as long as possible. Unfortunately, many of these tools "live a life of their own," that is, they are not well integrated to existing health informatics suites of tools [36]. Applying techniques developed for "Big Data" to accumulate clinical information from different sources and in a variety of formats provides opportunities for the active use of authentic, real-time patient data in developing health care and practice changes that embrace new and novel opportunities for analysis of clinical information. Among the future challenges are questions of how to incorporate these new opportunities to present sound, innovative care repertoires. It remains to be explored how such analytic techniques, applied to the plethora of available information, can add to knowledge and wisdom, and what future innovative practice models will be suggested. More research will also be appreciated to understand how to incorporate data from remote monitors in decision-making and clinical judgments without familiar, observational data to help in the interpretation of the discrete data.