Ottawa Model Of Research Use Research Articles

Implementing the dynamic appraisal of situational aggression in mental health units.

The aims of this study are to explain the intervention of implementing a structured violence risk assessment procedure in mental health inpatient units using the Ottawa Model of Research Use (OMRU) as a guiding framework and to consider nurses' perspectives of its clinical utility and implementation process. Patient aggression toward staff is a global concern in mental health units. The limited extant literature exploring the use of structured violence risk assessments in mental health units, although small and inconsistent, reveals some positive impacts on the incidence of aggression and staff's use of restrictive interventions. Although numerous violence risk assessment instruments have been developed and tested, their systematic implementation and use are still limited. A project titled "Safer Working Management" (111298) was conducted in a Finnish hospital district, across 3 mental health units. The 6 steps of OMRU were followed during implementation of the Dynamic Appraisal of Situational Aggression (DASA). Nurses' views toward structured violence risk assessment procedures varied. Although implementation of the DASA was seen as a useful method to increase discussions with patients and nursing staff, some staff preferred their own clinical judgment for assessment of violence risk. It is possible to use a specific model to promote the implementation of risk assessment instruments in mental health units. However, the complex mental health inpatient environment and the difficulties in understanding and managing aggressive patients present challenges for the implementation of structured violence risk assessment methods. The OMRU provides a tool for clinical nurse specialists to guide implementation process in mental health units. Clinical nurse specialists must promote training for staff regarding use of new innovations, such as the DASA. Implementation processes should be reviewed so that clinical nurse specialists can lead and support mental health staff to properly use structured violence risk assessment measures.

Hiding in plain sight: communication theory in implementation science.

BackgroundPoor communication among healthcare professionals is a pressing problem, contributing to widespread barriers to patient safety. The word “communication” means to share or make common. In the literature, two communication paradigms dominate: (1) communication as a transactional process responsible for information exchange, and (2) communication as a transformational process responsible for causing change. Implementation science has focused on information exchange attributes while largely ignoring transformational attributes of communication. In this paper, we debate the merits of encompassing both paradigms.DiscussionWe conducted a two-staged literature review searching for the concept of communication in implementation science to understand how communication is conceptualized. Twenty-seven theories, models, or frameworks were identified; only Rogers’ Diffusion of Innovations theory provides a definition of communication and includes both communication paradigms. Most models (notable exceptions include Diffusion of Innovations, The Ottawa Model of Research Use, and Normalization Process Theory) describe communication as a transactional process. But thinking of communication solely as information transfer or exchange misrepresents reality. We recommend that implementation science theories (1) propose and test the concept of shared understanding when describing communication, (2) acknowledge that communication is multi-layered, identify at least a few layers, and posit how identified layers might affect the development of shared understanding, (3) acknowledge that communication occurs in a social context, providing a frame of reference for both individuals and groups, (4) acknowledge the unpredictability of communication (and healthcare processes in general), and (5) engage with and draw on work done by communication theorists.SummaryImplementation science literature has conceptualized communication as a transactional process (when communication has been mentioned at all), thereby ignoring a key contributor to implementation intervention success. When conceptualized as a transformational process, the focus of communication moves to shared understanding and is grounded in human interactions and the way we go about constructing knowledge. Instead of hiding in plain sight, we suggest explicitly acknowledging the role that communication plays in our implementation efforts. By using both paradigms, we can investigate when communication facilitates implementation, when it does not, and how to improve it so that our implementation and clinical interventions are embraced by clinicians and patients alike.

Perceived factors influencing nurses' use of evidence-informed protocols for remote cancer treatment-related symptom management: A mixed methods study

PurposeTo assess factors perceived to influence nurses' use of symptom protocols when providing remote management for oncology patients. MethodA mixed methods descriptive study was guided by the Knowledge-to-Action Framework. In 2013, 8 focus groups and 7 interviews were conducted with 49 nurses or patients/family members in three ambulatory oncology programs within different provincial healthcare systems. Role-play with a protocol was used during nurse focus groups/interviews. Nurses who provided remote symptom support received a survey. Data was triangulated using thematic analysis guided by the Ottawa Model of Research Use. ResultsOver 90% of nurses provide telephone support during regular hours only. These symptom protocols were being used by 14% of nurses at one program. Nurses rated the protocols positively for content and format (>85%) but 20% indicated too complex. Protocol facilitators were systematic approach, comprehensive, and evidence-based. Protocol barriers were too long, not for symptom clusters, and inadequate space for documenting. To facilitate use, nurses need to enhance their knowledge (73%) and skills (58%), get access to resources, and obtain performance feedback. Nurse barriers included the learning curve, being unaware of protocols, and feeling tied to a script. Organizational barriers were communication challenges with patients, lack of electronic charting, and no clear direction to use them (54%). ConclusionsSeveral barriers and facilitators were perceived to influence the use of symptom protocols. Nurses and patients/family members identified similar factors. Interventions are needed to overcome barriers to nurses using the protocols such as education, clear organizational mandate, and integration with documentation.

Knowledge translation in physical therapy: from theory to practice

Purpose: Knowledge translation (KT) has emerged as a concept that can lead to a greater utilization of evidence-based research in systems of care. Despite a rise in KT research, the literature on KT in relation to physical therapy practice is scarce. This article provides physical therapists (PTs) with recommendations that can support the effective implementation of new knowledge and scientific evidence in clinical practice. Method: Recommendations are grounded in the Ottawa Model of Research Use and in the literature in KT in the health professions. Results: A well-established KT process, which is supported by a planning model, is essential to guide the implementation of scientific evidence. Consensus among all stakeholders about what evidence will be implemented must be reached. Context-related barriers and facilitators should be assessed and tailored active and multi-component interventions should be considered. Participation from individuals in intermediary positions (e.g. opinion leaders) supports implementation of KT interventions. Monitoring of the process and assessment of intended outcomes should be performed in order to assess the success of the implementation. Conclusion: Five major recommendations grounded in the Ottawa model are provided that can assist PTs with the complex task of implementing new knowledge in their clinical practice.Implications for RehabilitationIn order to support EBP, knowledge translation interventions can be used to support best practice.Implementation of new knowledge should be guided by a framework or a conceptual model.Consensus on the evidence must be reached and assessment of context-related factors should be done prior to the implementation of any KT intervention.Intervention strategies should be active, multi-component and include individuals with intermediary positions that can facilitate the KT process.

Diabetes Clinical Indicator Database: Advancing Chronic Disease Management in Diabetes Education

predetermined questions were constructed using the Ottawa Model of Research Use, to identify perceived gaps and barriers in postpartum care. The session was audio taped, transcribed and opinions thematically analyzed. Results: Participants’ responses revealed themes on the organization of health services: receipt of conflicting messages; the challenge of competingpriorities;apprehensionaboutpostpartumdiabetes testing; lack of ongoing support; difficulty applying knowledge to sustain behaviour change. Needs identified: child-friendly environments and skill based resources. Patient's recommendations: merge community and health services with follow-up testing, restructure services as a group support format and face-to-face contact was important. Implications and Conclusions: Future development of services should engage community resources in planning, development and implementation. Women with young children require care that is child friendly, flexible and optimizes the use of their limited time to support their own behaviour change and long-term health. Funded in part by the Public Health Agency of Canada.

Barriers and facilitators to the dissemination of DECISION+, a continuing medical education program for optimizing decisions about antibiotics for acute respiratory infections in primary care: A study protocol

BackgroundIn North America, acute respiratory infections are the main reason for doctors' visits in primary care. Family physicians and their patients overuse antibiotics for treating acute respiratory infections. In a pilot clustered randomized trial, we showed that DECISION+, a continuing medical education program in shared decision making, has the potential to reduce the overuse of antibiotics for treating acute respiratory infections. DECISION+ learning activities consisted of three interactive sessions of three hours each, reminders at the point of care, and feedback to doctors on their agreement with patients about comfort with the decision whether to use antibiotics. The objective of this study is to identify the barriers and facilitators to physicians' participation in DECISION+ with the goal of disseminating DECISION+ on a larger scale.Methods/designThis descriptive study will use mixed methods and retrospective and prospective components. All analyses will be based on an adapted version of the Ottawa Model of Research Use. First, we will use qualitative methods to analyze the following retrospective data from the pilot study: the logbooks of eight research assistants, the transcriptions of 15 training sessions, and 27 participant evaluations of the DECISION+ training sessions. Second, we will collect prospective data in semi-structured focus groups composed of family physicians to identify barriers and facilitators to the dissemination of a future training program similar to DECISION+. All 39 family physicians exposed to DECISION+ during the pilot project will be eligible to participate. We will use a self-administered questionnaire based on Azjen's Theory of Planned Behaviour to assess participants' intention to take part in future training programs similar to DECISION+.DiscussionBarriers and facilitators identified in this project will guide modifications to DECISION+, a continuing medical education program in shared decision making regarding the use of antibiotics in acute respiratory infections, to facilitate its dissemination in primary care on a large scale. Our results should help continuing medical educators develop a continuing medical education program in shared decision making for other clinically relevant topics. This will help optimize clinical decisions in primary care.

Interprofessional collaborative practice within cancer teams: Translating evidence into action. A mixed methods study protocol.

BackgroundA regional integrated cancer network has implemented a program (educational workshops, reflective and mentoring activities) designed to support the uptake of evidence-informed interprofessional collaborative practices (referred to in this text as EIPCP) within cancer teams. This research project, which relates to the Registered Nurses' Association of Ontario (RNAO) Best Practice Guidelines and other sources of research evidence, represents a unique opportunity to learn more about the factors and processes involved in the translation of evidence-based recommendations into professional practices. The planned study seeks to address context-specific challenges and the concerns of nurses and other stakeholders regarding the uptake of evidence-based recommendations to effectively promote and support interprofessional collaborative practices.AimThis study aims to examine the uptake of evidence-based recommendations from best practice guidelines intended to enhance interprofessional collaborative practices within cancer teams.DesignThe planned study constitutes a practical trial, defined as a trial designed to provide comprehensive information that is grounded in real-world healthcare dynamics. An exploratory mixed methods study design will be used. It will involve collecting quantitative data to assess professionals' knowledge and attitudes, as well as practice environment factors associated with effective uptake of evidence-based recommendations. Semi-structured interviews will be conducted concurrently with care providers to gather qualitative data for describing the processes involved in the translation of evidence into action from both the users' (n = 12) and providers' (n = 24) perspectives. The Graham et al. Ottawa Model of Research Use will serve to construct operational definitions of concepts, and to establish the initial coding labels to be used in the thematic analysis of the qualitative data. Quantitative and qualitative results will be merged during interpretation to provide complementary perspectives of interrelated contextual factors that enhance the uptake of EIPCP and changes in professional practices.DiscussionThe information obtained from the study will produce new knowledge on the interventions and sources of support most conducive to the uptake of evidence and building of capacity to sustain new interprofessional collaborative practice patterns. It will provide new information on strategies for overcoming barriers to evidence-informed interventions. The findings will also pinpoint critical determinants of 'what works and why' taking into account the interplay between evidence, operational, relational micro-processes of care, uniqueness of patients' needs and preferences, and the local context.

If you build it, they still may not come: outcomes and process of implementing a community-based integrated knowledge translation mapping innovation

BackgroundMaps and mapping tools through geographic information systems (GIS) are highly valuable for turning data into useful information that can help inform decision-making and knowledge translation (KT) activities. However, there are several challenges involved in incorporating GIS applications into the decision-making process. We highlight the challenges and opportunities encountered in implementing a mapping innovation as a KT strategy within the non-profit (public) health sector, reflecting on the processes and outcomes related to our KT innovations.MethodsA case study design, whereby the case is defined as the data analyst and manager dyad (a two-person team) in selected Ontario Early Year Centres (OEYCs), was used. Working with these paired individuals, we provided a series of interventions followed by one-on-one visits to ensure that our interventions were individually tailored to personal and local decision-making needs. Data analysis was conducted through a variety of qualitative assessments, including field notes, interview data, and maps created by participants. Data collection and data analysis have been guided by the Ottawa Model of Research Use (OMRU) conceptual framework.ResultsDespite our efforts to remove all barriers associated with our KT innovation (maps), our results demonstrate that both individual level and systemic barriers pose significant challenges for participants. While we cannot claim a causal association between our project and increased mapping by participants, participants did report a moderate increase in the use of maps in their organization. Specifically, maps were being used in decision-making forums as a way to allocate resources, confirm tacit knowledge about community needs, make financially-sensitive decisions more transparent, evaluate programs, and work with community partners.ConclusionsThis project highlights the role that maps can play and the importance of communicating the importance of maps as a decision support tool. Further, it represents an integrated knowledge project in the community setting, calling to question the applicability of traditional KT approaches when community values, minimal resources, and partners play a large role in decision making. The study also takes a unique perspective--where research producers and users work as dyad-pairs in the same organization--that has been under-explored to date in KT studies.

Applying knowledge to generate action: A community-based knowledge translation framework

Practical strategies are needed to translate research knowledge between researchers and users into action. For effective translation to occur, researchers and users should partner during the research process, recognizing the impact that knowledge, when translated into practice, will have on those most affected by that research. Participatory action research (PAR) was used to generate a rural community's knowledge of their children's health. The Ottawa Model of Research Use (OMRU), a knowledge translation framework, was used to guide the translation of that generative knowledge into action, and the more current knowledge-to-action (KTA) conceptual framework provided the rationale for the graphical depiction of engagement of a rural community in knowledge translation. The definitions, perspectives, best practices, and existing frameworks of knowledge translation are outlined. The foundational underpinnings and elements of PAR, the OMRU, and KTA are linked to form a conceptual framework for knowledge translation in a rural community context. Select strategies noted in OMRU to translate existing knowledge informed aspects of PAR to generate an action. Diverse yet complementary approaches could be used by health professionals to advance the theory, method, and research of knowledge translation and exchange, regardless of context. Knowledge needs to be relevant, appropriate, applicable, timely, and reasonable to influence change.

Barriers and supports to implementation of MDI/spacer use in nine Canadian pediatric emergency departments: a qualitative study

BackgroundDespite recent research supporting the use of metered dose inhalers with spacer devices (MDI/spacers) in pediatric emergency departments (PEDs) for acute exacerbations of asthma, uptake of this practice has been slow. The objectives of this study were to determine the barriers and supports to implementing MDI/spacer research and to identify factors associated with early and late adoption of MDI/spacers in Canadian PEDs.MethodsUsing a comparative case study design, we classified nine tertiary care pediatric hospital PEDs based on their stage of implementation. Data were collected using focus group interviews with physicians, registered nurses (RNs), and respiratory therapists (RTs), and individual interviews with both patient care and medical directors at each site. Initial coding was based on the Ottawa Model of Research Use (OMRU) categories of elements known to influence the uptake of innovations.ResultsOne hundred and fifty healthcare professionals from nine different healthcare institutions participated in this study. Lack of leadership in the form of a research champion, a lack of consensus about the benefits of MDI/spacers among staff, perceived resistance from patients/parents, and perceived increased cost and workload associated with MDI/spacer use were the most prevalent barriers to the adoption of the MDI/spacer. Common strategies used by early-adopting sites included the active participation of all professional groups in the adoption process in addition to a well-planned and executed educational component for staff, patients, and families. Early adopter sites were also more likely to have the MDI/spacer included in a clinical protocol/pathway.ConclusionPotential barriers and supports to implementation have been identified that will help EDs adopt MDI/spacer use. Future interventions intended to increase MDI/spacer use in PEDs will need to be sensitive to the barriers identified in this study.

Promoting Evidence-Based Dysphagia Assessment and Management by Nurses

The Ottawa Model of Research Use guided the Hospital Elder Life Program nursing staff at a community hospital in promoting dysphagia assessment and management. The effect of an educational program and educational outreach on nurses' knowledge retention and nurse-initiated speech language pathology (SLP) referrals were assessed. The sample consisted of 122 nurses. Repeated measures analysis of variance demonstrated significant differences among the pretest and posttests immediately after and at 2 and 6 months later (F[3,70] = 10.126, p < 0.001). Nurses were more likely to initiate SLP referrals after the program. Improving practice requires stakeholder engagement and multiple strategies to sustain change.

Mapping as a knowledge translation tool for Ontario Early Years Centres: views from data analysts and managers

BackgroundLocal Ontario Early Years Centres (OEYCs) collect timely and relevant local data, but knowledge translation is needed for the data to be useful. Maps represent an ideal tool to interpret local data. While geographic information system (GIS) technology is available, it is less clear what users require from this technology for evidence-informed program planning. We highlight initial challenges and opportunities encountered in implementing a mapping innovation (software and managerial decision-support) as a knowledge translation strategy.MethodsUsing focus groups, individual interviews and interactive software development events, we taped and transcribed verbatim our interactions with nine OEYCs in Ontario, Canada. Research participants were composed of data analysts and their managers. Deductive analysis of the data was based on the Ottawa Model of Research Use, focusing on the innovation (the mapping tool and maps), the potential adopters, and the environment.ResultsChallenges associated with the innovation included preconceived perceptions of a steep learning curve with GIS software. Challenges related to the potential adopters included conflicting ideas about tool integration into the organization and difficulty with map interpretation. Lack of funds, lack of availability of accurate data, and unrealistic reporting requirements represent environmental challenges.ConclusionDespite the clear need for mapping software and maps, there remain several challenges to their effective implementation. Some can be modified, while other challenges might require attention at the systemic level. Future research is needed to identify barriers and facilitators related to using mapping software and maps for decision-making by other users, and to subsequently develop mapping best practices guidelines to assist community-based agencies in circumventing some challenges, and support information equity across a region.

Correction: Using participatory design to develop (public) health decision support systems through GIS

BackgroundOrganizations that collect substantial data for decision-making purposes are often characterized as being 'data rich' but 'information poor'. Maps and mapping tools can be very useful for research transfer in converting locally collected data into information. Challenges involved in incorporating GIS applications into the decision-making process within the non-profit (public) health sector include a lack of financial resources for software acquisition and training for non-specialists to use such tools. This on-going project has two primary phases. This paper critically reflects on Phase 1: the participatory design (PD) process of developing a collaborative web-based GIS tool.MethodsA case study design is being used whereby the case is defined as the data analyst and manager dyad (a two person team) in selected Ontario Early Year Centres (OEYCs). Multiple cases are used to support the reliability of findings. With nine producer/user pair participants, the goal in Phase 1 was to identify barriers to map production, and through the participatory design process, develop a web-based GIS tool suited for data analysts and their managers. This study has been guided by the Ottawa Model of Research Use (OMRU) conceptual framework.ResultsDue to wide variations in OEYC structures, only some data analysts used mapping software and there was no consistency or standardization in the software being used. Consequently, very little sharing of maps and data occurred among data analysts. Using PD, this project developed a web-based mapping tool (EYEMAP) that was easy to use, protected proprietary data, and permit limited and controlled sharing between participants. By providing data analysts with training on its use, the project also ensured that data analysts would not break cartographic conventions (e.g. using a chloropleth map for count data). Interoperability was built into the web-based solution; that is, EYEMAP can read many different standard mapping file formats (e.g. ESRI, MapInfo, CSV).DiscussionBased on the evaluation of Phase 1, the PD process has served both as a facilitator and a barrier. In terms of successes, the PD process identified two key components that are important to users: increased data/map sharing functionality and interoperability. Some of the challenges affected developers and users; both individually and as a collective. From a development perspective, this project experienced difficulties in obtaining personnel skilled in web application development and GIS. For users, some data sharing barriers are beyond what a technological tool can address (e.g. third party data). Lastly, the PD process occurs in real time; both a strength and a limitation. Programmatic changes at the provincial level and staff turnover at the organizational level made it difficult to maintain buy-in as participants changed over time. The impacts of these successes and challenges will be evaluated more concretely at the end of Phase 2.ConclusionPD approaches, by their very nature, encourage buy-in to the development process, better addresses user-needs, and creates a sense of user-investment and ownership.

Adoption and sustainability of decision support for patients facing health decisions: an implementation case study in nursing

BackgroundEffective interventions prepare patients for making values-sensitive health decisions by helping them become informed and clarifying their values for each of the options. However, patient decision support interventions have not been widely implemented and little is known about effective models for delivering them to patients. The purpose of this study was to describe call centre nurses' adoption of a decision support protocol into practice following exposure to an implementation intervention and to identify factors influencing sustainable nursing practice changes.MethodsExploratory case study at a Canadian province-wide call centre guided by the Ottawa Model of Research Use. Data sources included a survey of nurses who participated in an implementation intervention (n = 31), 2 focus groups with nurses, interviews with 4 administrators, and a document review.ResultsTwenty-five of 31 nurses responded to the survey measuring adoption of decision support in practice. Of the 25 nurses, 11 had used the decision support protocol in their practice within one month of the intervention. Twenty-two of the 25 intended to use it within the next three months. Although some nurses found it challenging to begin using the protocol, most nurses reported that it: a) helped them recognize callers needing decision support; b) changed their approach to handling these calls; and c) was a positive enhancement to their practice. Strategies identified to promote sustainability of practice changes included integration of the decision support protocol in the call centre database, streamlining the patient decision aids for easier use via telephone, clarifying the administrative direction for the call centre's program, creating a call length guideline specific for these calls, incorporating decision support training in the staff development plan, and informing the public of this enhanced service.ConclusionAlthough most nurses adopted the decision support protocol for coaching callers facing values-sensitive decisions, to sustain practice changes, interventions are required to manage barriers in the practice environment and integrate decision support into the organization's policies, resources, and routine activities.

Knowledge translation in developing countries

There is increasing evidence that the application of knowledge in developing countries is failing. One reason is the woeful shortage of health workers, but as this is redressed, it is also crucial that we have an evidence base of what works to minimize the "know-do gap." The World Health Organization and other international organizations are actively building momentum to promote research to determine effective strategies for knowledge translation (KT). At this time, the evidence base for the effectiveness of those strategies is not definitive in developed countries and is relatively sparse in developing countries. It appears, however, that the effectiveness of these strategies is highly variable and dependent on the setting, and success hinges on whether the strategies have been tailored. A useful framework to provide direction for tailoring interventions is the Ottawa Model of Research Use (OMRU). Underlying OMRU is the principle that success rests with tailoring KT strategies to the salient barriers and supports found within the setting. The model recommends that barriers and supports found in the practice environment or as characteristics of potential adopters and the evidence-based innovation or research evidence be assessed and then the KT strategy tailored and executed. The model also recommends that whether the research has been applied and has resulted in improved health outcomes should be measured. Studies in developing countries, although few, illustrate that the OMRU approach may be a valid method of tackling the challenges of KT strategies to improve health care in developing countries.

The Ottawa Model of Research Use

To improve performance of a neonatal transport team by implementing a research-based family assessment instrument. Objectives included providing a structure for evaluating families and fostering the healthcare relationship. Neonatal transports are associated with family crises. Transport teams require a comprehensive framework to accurately assess family responses to adversity and tools to guide their practice toward parental mastery of the event. Currently, there are no assessment tools that merge family nursing expertise with neonatal transport. A family assessment tool grounded in contemporary family nursing theory and research was developed by a clinical nurse specialist. The Ottawa Model of Research Use guided the process of piloting the innovation with members of a transport team. Focus groups, interviews, and surveys were conducted to create profiles of barriers and facilitators to research use by team members. Tailored research transfer strategies were enacted based on the profile results. Formative evaluations demonstrated improvements in team members' perceptions of their knowledge, family centeredness, and ability to assess and intervene with families. The family assessment tool is currently being incorporated into Clinical Practice Guidelines for Transport and thus will be considered standard care. Use of a family assessment tool is an effective way of appraising families and addressing suffering. The Ottawa Model of Research Use provided a framework for implementing the clinical innovation. A key role of the clinical nurse specialist is to influence nursing practice by fostering research use by practitioners. When developing and implementing a clinical innovation, input from end users and consumers is pivotal. Incorporating the innovation into a practice guideline provides a structure to imbed research evidence into practice.

Using the Ottawa Model of Research Use to implement a skin care program.

Addressing skin care issues requires a systematic and comprehensive approach. We used the pragmatic Ottawa Model of Research Use to guide the implementation of clinical practice guidelines in a surgical program of a tertiary care hospital. Assessments were made of existing clinical practice guidelines, the practice environment, and the potential adopters. With this information, we tailored strategies to address the barriers and to implement the guidelines. A formative evaluation demonstrated positive results.

Toward a Comprehensive Interdisciplinary Model of Health Care Research Use

Numerous health care disciplines have noted that insufficient research evidence is used in clinical practice. This situation denies optimal care to patients and potentially increases system costs. A practical theoretical framework for policymakers intent on promoting an evidence-based approach to the transfer and use of research findings in clinical practice settings is presented. The Ottawa Model of Research Use (OMRU) has a comprehensive interdisciplinary focus and consists of six key elements: the practice environment, potential adopters of the evidence, the evidence-based innovation, research transfer strategies, the evidence adoption, and health-related and other outcomes. Model elements and the interactive relationships among them are described.