Making sense of implementation theories, models and frameworks — TEI-tagged view

Per NilsenpersName (2015date). “Making sense of implementation theories, models and frameworks.” Implementation Sciencetitle·j.

Object of study — theories, modelsterm, and frameworksterm used to describe, explain, guide, and evaluate implementationterm in implementation scienceterm

Research question — how implementation theoriesterm, modelsterm, and frameworksterm differ in aims, assumptions, origins, and practical uses, and how they can be classified for appropriate selection

Contribution — a five-category taxonomy connecting three overarching aims of theoretical approaches in implementation scienceterm

Full text — tagged

Making sense of implementation theoriesterm, modelsterm and frameworksterm Abstract Implementation scienceterm has progressed towards increased use of theoretical approaches to provide better understanding and explanation of how and why implementationterm succeeds or fails. The aim of this article is to propose a taxonomy that distinguishes between different categories of theories, modelsterm and frameworksterm in implementation scienceterm, to facilitate appropriate selection and application of relevant approaches in implementationterm research and practice and to foster cross-disciplinary dialogue among implementationterm researchers.

Theoretical approaches used in implementation scienceterm have three overarching aims: describing and/or guiding the process of translating research into practice (process modelsterm); understanding and/or explaining what influences implementation outcomesterm (determinant frameworksterm, classic theoriesterm, implementation theoriesterm); and evaluating implementationterm (evaluation frameworksterm).

This article proposes five categories of theoretical approaches to achieve three overarching aims. These categories are not always recognized as separate types of approaches in the literature. While there is overlap between some of the theories, modelsterm and frameworksterm, awareness of the differences is important to facilitate the selection of relevant approaches. Most determinant frameworksterm provide limited “how-to” support for carrying out implementationterm endeavours since the determinants usually are too generic to provide sufficient detail for guiding an implementationterm process. And while the relevance of addressing barriersterm and enablersterm to translating research into practice is mentioned in many process modelsterm, these modelsterm do not identify or systematically structure specific determinants associated with implementationterm success. Furthermore, process modelsterm recognize a temporal sequence of implementationterm endeavours, whereas determinant frameworksterm do not explicitly take a process perspective of implementationterm.

Keywords: Theoryterm, Modelterm, Frameworkterm, Evaluation, Contextterm Background Implementation scienceterm was borne out of a desire to address challenges associated with the use of research to achieve more evidence-based practice (EBP) in health care and other areas of professional practice. Early implementationterm research was empirically driven and did not always pay attention to the theoretical underpinnings of implementationterm. Eccles et al. ([ 1 ]:108) remarked that this research seemed like “an expensive version of trial-and-error”. A reviewterm·mth of guideline implementationterm strategies by Davies et al. [ 2 ] noted that only 10% of the studies identified provided an explicit rationale for their strategies. Mixed results of implementing EBP in various settings were often attributed to a limited theoretical basis [ 1 , 3 - 5 ]. Poor theoretical underpinning makes it difficult to understand and explain how and why implementationterm succeeds or fails, thus restraining opportunities to identify factors that predict the likelihood of implementationterm success and develop better strategies to achieve more successful implementationterm.

However, the last decade of implementation scienceterm has seen wider recognition of the need to establish the theoretical bases of implementationterm and strategies to facilitate implementationterm. There is mounting interest in the use of theories, modelsterm and frameworksterm to gain insights into the mechanisms by which implementationterm is more likely to succeed. Implementationterm studies now apply theories borrowed from disciplines such as psychology, sociology and organizational theoryterm as well as theories, modelsterm and frameworksterm that have emerged from within implementation scienceterm. There are now so many theoretical approaches that some researchers have complained about the difficulties of choosing the most appropriate [ 6 - 11 ].

This article seeks to further implementation scienceterm by providing a narrative reviewterm of the theories, modelsterm and frameworksterm applied in this research field. The aim is to describe and analyse how theories, modelsterm and frameworksterm have been applied in implementation scienceterm and propose a taxonomy that distinguishes between different approaches to advance clarity and achieve a common terminology. The ambition is to facilitate appropriate selection and application of relevant approaches in implementationterm studies and foster cross-disciplinary dialogue among implementationterm researchers. The importance of a clarifying taxonomy has evolved during the many discussions on theoretical approaches used within implementation scienceterm that the author has had over the past few years with fellow implementationterm researchers, as well as reflection on the utility of different approaches in various situations.

Implementation scienceterm is defined as the scientific study of methods to promote the systematic uptake of research findings and other EBPs into routine practice to improve the quality and effectiveness of health services and care [ 12 ]. The terms knowledge translation, knowledge exchange, knowledge transfer, knowledge integration and research utilization are used to describe overlapping and interrelated research on putting various forms of knowledge, including research, to use [ 8 , 13 - 16 ]. Implementationterm is part of a diffusion-dissemination-implementation continuumterm: diffusionterm is the passive, untargeted and unplanned spread of new practices; disseminationterm is the active spread of new practices to the target audience using planned strategies; and implementationterm is the process of putting to use or integrating new practices within a setting [ 16 , 17 ].

A narrative reviewterm of selective literature was undertaken to identify key theories, modelsterm and frameworksterm used in implementation scienceterm. The narrative reviewterm approach gathers information about a particular subject from many sources and is considered appropriate for summarizing and synthesizing the literature to draw conclusions about “what we know” about the subject. Narrative reviewsterm yield qualitative results, with strengths in capturing diversities and pluralities of understanding [ 18 , 19 ]. Six textbooks that provide comprehensive overviews of research regarding implementation scienceterm and implementationterm of EBP were consulted: Rycroft-Malone and Bucknall [ 20 ], Nutley et al. [ 21 ], Greenhalgh et al. [ 17 ], Grol et al. [ 22 ], Straus et al. [ 23 ] and Brownson et al. [ 24 ]. A few papers presenting overviews of theories, modelsterm and frameworksterm used in implementation scienceterm were also used: Estabrooks et al. [ 14 ], Sales et al. [ 4 ], Graham and Tetroe [ 25 ], Mitchell et al. [ 8 ], Flottorp et al. [ 26 ], Meyers et al. [ 27 ] and Tabak et al. [ 28 ]. In addition, Implementation Scienceterm (first published in 2006) was searched using the terms “theoryterm”, “modelterm” and “frameworkterm” to identify relevant articles. The titles and abstracts of the identified articles were scanned, and those that were relevant to the study aim were read in full.

Discussion Theories, modelsterm and frameworksterm in the general literature Generally, a theoryterm may be defined as a set of analytical principles or statements designed to structure our observation, understanding and explanation of the world [ 29 - 31 ]. Authors usually point to a theoryterm as being made up of definitions of variables, a domain where the theoryterm applies, a set of relationships between the variables and specific predictions [ 32 - 35 ]. A “good theoryterm” provides a clear explanation of how and why specific relationships lead to specific events. Theories can be described on an abstraction continuumterm. High abstraction level theories (general or grand theories) have an almost unlimited scope, middle abstraction level theories explain limited sets of phenomena and lower level abstraction theories are empirical generalizations of limited scope and application [ 30 , 36 ].

A modelterm typically involves a deliberate simplification of a phenomenon or a specific aspect of a phenomenon. Modelsterm need not be completely accurate representations of reality to have value [ 31 , 37 ]. Modelsterm are closely related to theoryterm and the difference between a theoryterm and a modelterm is not always clear. Modelsterm can be described as theories with a more narrowly defined scope of explanation; a modelterm is descriptive, whereas a theoryterm is explanatory as well as descriptive [ 29 ].

A frameworkterm usually denotes a structure, overview, outline, system or plan consisting of various descriptive categoriesterm, e.g. concepts, constructs or variables, and the relations between them that are presumed to account for a phenomenon [ 38 ]. Frameworksterm do not provide explanations; they only describe empirical phenomena by fitting them into a set of categories [ 29 ].

Theories, modelsterm and frameworksterm in implementation scienceterm It was possible to identify three overarching aims of the use of theories, modelsterm and frameworksterm in implementation scienceterm: (1) describing and/or guiding the process of translating research into practice, (2) understanding and/or explaining what influences implementation outcomesterm and (3) evaluating implementationterm. Theoretical approaches which aim at understanding and/or explaining influences on implementation outcomesterm (i.e. the second aim) can be further broken down into determinant frameworksterm, classic theoriesterm and implementation theoriesterm based on descriptions of their origins, how they were developed, what knowledge sources they drew on, stated aims and applications in implementation scienceterm. Thus, five categories of theoretical approaches used in implementation scienceterm can be delineated (Table 1 ; Figure 1 ): Process modelsterm Determinant frameworksterm Classic theoriesterm Implementation theoriesterm Evaluation frameworksterm Five categories of theories, modelsterm and frameworksterm used in implementation scienceterm Three aims of the use of theoretical approaches in implementation scienceterm and the five categories of theories, modelsterm and frameworksterm.

Although theories, modelsterm and frameworksterm are distinct concepts, the terms are sometimes used interchangeably in implementation scienceterm [ 9 , 14 , 39 ]. A theoryterm in this field usually implies some predictive capacity (e.g. to what extent do health care practitioners’ attitudes and beliefs concerning a clinical guideline predict their adherence to this guideline in clinical practice?) and attempts to explain the causal mechanisms of implementationterm. Modelsterm in implementation scienceterm are commonly used to describe and/or guide the process of translating research into practice (i.e. “implementationterm practice”) rather than to predict or analyse what factors influence implementation outcomesterm (i.e. “implementationterm research”). Frameworksterm in implementation scienceterm often have a descriptive purpose by pointing to factors believed or found to influence implementation outcomesterm (e.g. health care practitioners’ adoption of an evidence-based patient intervention). Neither modelsterm nor frameworksterm specify the mechanisms of change; they are typically more like checklists of factors relevant to various aspects of implementationterm.

Describing and/or guiding the process of translating research into practice Process modelsterm Process modelsterm are used to describe and/or guide the process of translating research into practice. Modelsterm by Huberman [ 40 ], Landry et al. [ 41 ], the CIHR (Canadian Institutes of Health Research) Knowledge Modelterm of Knowledge Translation [ 42 ], Davis et al. [ 43 ], Majdzadeh et al. [ 44 ] and the K2A (Knowledge-to-Action) Frameworkterm [ 15 ] outline phases or stages of the research-to-practice process, from discovery and production of research-based knowledge to implementationterm and use of research in various settings.

Early research-to-practice (or knowledge-to-action) modelsterm tended to depict rational, linear processes in which research was simply transferred from producers to users. However, subsequent modelsterm have highlighted the importance of facilitation to support the process and placed more emphasis on the contextsterm in which research is implemented and used. Thus, the attention has shifted from a focus on production, diffusionterm and disseminationterm of research to various implementationterm aspects [ 21 ].

So-called action (or planned action) modelsterm are process modelsterm that facilitate implementationterm by offering practical guidance in the planning and execution of implementationterm endeavours and/or implementationterm strategies. Action modelsterm elucidate important aspects that need to be considered in implementationterm practice and usually prescribe a number of stages or steps that should be followed in the process of translating research into practice. Action modelsterm have been described as active by Graham et al. ([ 45 ]:185) because they are used “to guide or cause change”. It should be noted that the terminology is not fully consistent, as some of these modelsterm are referred to as frameworksterm, for instance the Knowledge-to-Action Frameworkterm [ 46 ].

Many of the action modelsterm originate from the nursing-led field of research use/utilization; well-known examples include the Stetler Modelterm [ 47 ], the ACE (Academic Center for Evidence-Based Practice) Star Modelterm of Knowledge Transformation [ 48 ], the Knowledge-to-Action Frameworkterm [ 13 ], the Iowa Modelterm [ 49 , 50 ] and the Ottawa Modelterm [ 51 , 52 ]. There are also numerous examples of similar “how-to-implement” modelsterm that have emerged from other fields, including modelsterm developed by Grol and Wensing [ 53 ], Pronovost et al. [ 54 ] and the Quality Implementationterm Frameworkterm [ 27 ], all of which are intended to provide support for planning and managing implementationterm endeavours.

The how-to-implement modelsterm typically emphasize the importance of careful, deliberate planning, especially in the early stages of implementationterm endeavours. In many ways, they present an ideal view of implementationterm practice as a process that proceeds step-wise, in an orderly, linear fashion. Still, authors behind most modelsterm emphasize that the actual process is not necessarily sequential. Many of the action modelsterm mentioned here have been subjected to testing or evaluation, and some have been widely applied in empirical research, underscoring their usefulness [ 9 , 55 ].

The process modelsterm vary with regard to how they were developed. Modelsterm such as the Stetler Modelterm [ 47 , 56 ] and the Iowa Modelterm [ 49 , 50 ] were based on the originators’ own experiences of implementing new practices in various settings (although they were also informed by research and expert opinion). In contrast, modelsterm such as the Knowledge-to-Action Frameworkterm [ 45 ] and the Quality Implementationterm Frameworkterm [ 27 ] have relied on literature reviewsterm·mth of theories, modelsterm, frameworksterm and individual studies to identify key features of successful implementationterm endeavours.

Understanding and explaining what influences implementation outcomesterm Determinant frameworksterm Determinant frameworksterm describe general types (also referred to as classes or domains) of determinants that are hypothesized or have been found to influence implementation outcomesterm, e.g. health care professionals’ behaviourterm change or adherence to a clinical guideline. Each type of determinant typically comprises a number of individual barriersterm (hinders, impediments) and/or enablersterm (facilitators), which are seen as independent variables that have an impact on implementation outcomesterm, i.e. the dependent variable. Some frameworksterm also hypothesize relationships between these determinants (e.g. [ 17 , 57 , 58 ]), whereas others recognize such relationships without clarifying them (e.g. [ 59 , 60 ]). Information about what influences implementation outcomesterm is potentially useful for designing and executing implementationterm strategies that aim to change relevant determinants.

The determinant frameworksterm do not address how change takes place or any causal mechanisms, underscoring that they should not be considered theories. Many frameworksterm are multilevel, identifying determinants at different levels, from the individual user or adopter (e.g. health care practitioners) to the organization and beyond. Hence, these integrative frameworksterm recognize that implementationterm is a multidimensional phenomenon, with multiple interacting influences.

The determinant frameworksterm were developed in different ways. Many frameworksterm (e.g. [ 17 , 21 , 22 , 57 , 59 , 61 ]) were developed by synthesizing results from empirical studies of barriersterm and enablersterm for implementationterm success. Other frameworksterm have relied on existing determinant frameworksterm and relevant theories in various disciplines, e.g. the frameworksterm by Gurses et al. [ 58 ] and CFIR (Consolidated Frameworkterm for Implementationterm Research) [ 60 ].

Several frameworksterm have drawn extensively on the originator’s own experiences of implementing new practices. For instance, the Understanding-User-Context Frameworkterm [ 62 ] and Active Implementationterm Frameworksterm [ 63 ] were both based on a combination of literature reviewsterm·mth and the originators’ implementationterm experiences. Meanwhile, PARIHS (Promoting Action on Research Implementationterm in Health Services) [ 5 , 64 ] emerged from the observation that successful implementationterm in health care might be premised on three key determinants (characteristics of the evidence, contextterm and facilitation), a proposition which was then analysed in four empirical case studies; PARIHS has subsequently undergone substantial research and development work [ 64 ] and has been widely applied [ 65 ].

Theoretical Domains Frameworkterm represents another approach to developing determinant frameworksterm. It was constructed on the basis of a synthesis of 128 constructs related to behaviourterm change found in 33 behaviourterm change theories, including many social cognitive theories [ 10 ]. The constructs are sorted into 14 theoretical domains (originally 12 domains), e.g. knowledge, skills, intentions, goals, social influences and beliefs about capabilities [ 66 ]. Theoretical Domains Frameworkterm does not specify the causal mechanisms found in the original theories, thus sharing many characteristics with determinant frameworksterm.

The determinant frameworksterm account for five types of determinants, as shown in Table 2 , which provides details of eight of the most commonly cited frameworksterm in implementation scienceterm. The frameworksterm are superficially quite disparate, with a broad range of terms, concepts and constructs as well as different outcomes, yet they are quite similar with regard to the general types of determinants they account for. Hence, implementationterm researchers agree to a large extent on what the main influences on implementation outcomesterm are, albeit to a lesser extent on which terms that are best used to describe these determinants.

Implementationterm determinants and outcomes in eight determinant frameworksterm The frameworksterm describe “implementationterm objects” in terms of research, guidelines, interventions, innovations and evidence (i.e. research-based knowledge in a broad sense). Outcomes differ correspondingly, from adherence to guidelines and research use, to successful implementationterm of interventions, innovations, evidence, etc. (i.e. the application of research-based knowledge in practice). The relevance of the end users (e.g. patients, consumers or community populations) of the implemented object (e.g. an EBP) is not explicitly addressed in some frameworksterm (e.g. [ 17 , 21 , 67 ]), suggesting that this is an area where further research is needed for better analysis of how various end users may influence implementationterm effectiveness.

Determinant frameworksterm imply a systems approachterm to implementationterm because they point to multiple levels of influence and acknowledge that there are relationships within and across the levels and different types of determinants. A system can be understood only as an integrated whole because it is composed not only of the sum of its components but also by the relationships among those components [ 68 ]. However, determinants are often assessed individually in implementationterm studies (e.g. [ 69 - 72 ]), (implicitly) assuming a linear relationship between the determinants and the outcomes and ignoring that individual barriersterm and enablersterm may interact in various ways that can be difficult to predict. For instance, there could be synergistic effects such that two seemingly minor barriersterm constitute an important obstacle to successful outcomes if they interact. Another issue is whether all relevant barriersterm and enablersterm are examined in these studies, which are often based on survey questionnaires, and are thus biased by the researcher’s selection of determinants. Surveying the perceived importance of a finite set of predetermined barriersterm can yield insights into the relative importance of these particular barriersterm but may overlook factors that independently affect implementation outcomesterm. Furthermore, there is the issue of whether the barriersterm and enablersterm are the actual determinants (i.e. whether they have actually been experienced or encountered) and the extent to which they are perceived to exist (i.e. they are more hypothetical barriersterm and enablersterm). The perceived importance of particular factors may not always correspond with the actual importance.

The contextterm is an integral part of all the determinant frameworksterm. Described as “an important but poorly understood mediator of change and innovation in health care organizations” ([ 73 ]:79), the contextterm lacks a unifying definition in implementation scienceterm (and related fields such as organizational behaviourterm and quality improvement). Still, contextterm is generally understood as the conditions or surroundings in which something exists or occurs, typically referring to an analytical unit that is higher than the phenomena directly under investigation. The role afforded the contextterm varies, from studies (e.g. [ 74 - 77 ]) that essentially view the contextterm in terms of a physical “environment or setting in which the proposed change is to be implemented” ([ 5 ]:150) to studies (e.g. [ 21 , 74 , 78 ]) that assume that the contextterm is something more active and dynamic that greatly affects the implementationterm process and outcomes. Hence, although implementation scienceterm researchers agree that the contextterm is a critically important concept for understanding and explaining implementationterm, there is a lack of consensus regarding how this concept should be interpreted, in what ways the contextterm is manifested and the means by which contextual influences might be captured in research.

The different types of determinants specified in determinant frameworksterm can be linked to classic theoriesterm. Thus, psychological theories that delineate factors influencing individual behaviourterm change are relevant for analysing how user/adopter characteristics affect implementation outcomesterm, whereas organizational theories concerning organizational climate, culture and leadership are more applicable for addressing the influence of the contextterm on implementation outcomesterm.

Classic theoriesterm Implementationterm researchers are also wont to apply theories from other fields such as psychology, sociology and organizational theoryterm. These theories have been referred to as classic (or classic change) theories to distinguish them from research-to-practice modelsterm [ 45 ]. They might be considered passive in relation to action modelsterm because they describe change mechanisms and explain how change occurs without ambitions to actually bring about change.

Psychological behaviourterm change theories such as the Theoryterm of Reasoned Action [ 79 ], the Social Cognitive Theoryterm [ 80 , 81 ], the Theoryterm of Interpersonal Behaviourterm [ 82 ] and the Theoryterm of Planned Behaviourterm [ 83 ] have all been widely used in implementation scienceterm to study determinants of “clinical behaviourterm” change [ 84 ]. Theories such as the Cognitive Continuum Theoryterm [ 85 ], the Novice-Expert Theoryterm [ 86 ], the Cognitive-Experiential Self-Theory [ 87 ] and habit theories (e.g. [ 88 , 89 ]) may also be applicable for analysing cognitive processes involved in clinical decision-making and implementing EBP, but they are not as extensively used as the behaviourterm change theories.

Theories regarding the collective (such as health care teams) or other aggregate levels are relevant in implementation scienceterm, e.g. theories concerning professions and communities of practice, as well as theories concerning the relationships between individuals, e.g. social networks and social capital [ 14 , 53 , 90 - 93 ]. However, their use is not as prevalent as the individual-level theories.

There is increasing interest among implementationterm researchers in using theories concerning the organizational level because the contextterm of implementationterm is becoming more widely acknowledged as an important influence on implementation outcomesterm. Theories concerning organizational culture, organizational climate, leadership and organizational learning are relevant for understanding and explaining organizational influences on implementationterm processes [ 21 , 53 , 57 , 94 - 101 ]. Several organization-level theories might have relevance for implementation scienceterm. For instance, Estabrooks et al. [ 14 ] have proposed the use of the Situated Change Theoryterm [ 102 ] and the Institutional Theoryterm [ 103 , 104 ], whereas Plsek and Greenhalgh [ 105 ] have suggested the use of complexity science [ 106 ] for better understanding of organizations. Meanwhile, Grol et al. [ 22 ] have highlighted the relevance of economic theories and theories of innovative organizations. However, despite increased interest in organizational theories, their actual use in empirical implementationterm studies thus far is relatively limited.

The Theory of Diffusionterm, as popularized through Rogers’ work on the spread of innovations, has also influenced implementation scienceterm. The theoryterm’s notion of innovation attributesterm, i.e. relative advantage, compatibility, complexity, trialability and observability [ 107 ], has been widely applied in implementation scienceterm, both in individual studies (e.g. [ 108 - 110 ]) and in determinant frameworksterm (e.g. [ 17 , 58 , 60 ]) to assess the extent to which the characteristics of the implementationterm object (e.g. a clinical guideline) affect implementation outcomesterm. Furthermore, the Theory of Diffusionterm highlights the importance of intermediary actors (opinion leaders, change agents and gate-keepers) for successful adoption and implementationterm [ 107 ], which is reflected in roles described in numerous implementationterm determinant frameworksterm (e.g. [ 63 , 64 ]) and implementationterm strategy taxonomies (e.g. [ 111 - 114 ]). The Theory of Diffusionterm is considered the single most influential theoryterm in the broader field of knowledge utilization of which implementation scienceterm is a part [ 115 ].

Implementation theoriesterm There are also numerous theories that have been developed or adapted by researchers for potential use in implementation scienceterm to achieve enhanced understanding and explanation of certain aspects of implementationterm. Some of these have been developed by modifying certain features of existing theories or concepts, e.g. concerning organizational climate and culture. Examples include theories such as Implementationterm Climate [ 116 ], Absorptive Capacity [ 117 ] and Organizational Readiness [ 118 ]. The adaptation allows researchers to prioritize aspects considered to be most critical to analyse issues related to the how and why of implementationterm, thus improving the relevance and appropriateness to the particular circumstances at hand.

COM-Bterm (Capability, Opportunity, Motivation and Behaviourterm) represents another approach to developing theories that might be applicable in implementation scienceterm. This theoryterm began by identifying motivation as a process that energizes and directs behaviourterm. Capability and opportunity were added as necessary conditions for a volitional behaviourterm to occur, given sufficient motivation, on the basis of a US consensus meeting of behavioural theorists and a principle of US criminal law (which considers prerequisites for performance of specified volitional behavioursterm) [ 119 ]. COM-Bterm posits that capability, opportunity and motivationterm generate behaviourterm, which in turn influences the three components. Opportunity and capability can influence motivation, while enacting a behaviourterm can alter capability, motivation and opportunity [ 66 ].

Another theoryterm used in implementation scienceterm, the Normalization Process Theoryterm [ 120 ], began life as a modelterm, constructed on the basis of empirical studies of the implementationterm of new technologies [ 121 ]. The modelterm was subsequently expanded upon and developed into a theoryterm as change mechanisms and interrelations between various constructs were delineated [ 122 ]. The theoryterm identifies four determinants of embedding (i.e. normalizing) complex interventions in practice (coherenceterm or sense making, cognitive participationterm or engagement, collective actionterm and reflexive monitoringterm) and the relationships between these determinants [ 123 ].

Evaluating implementationterm Evaluation frameworksterm There is a category of frameworksterm that provide a structure for evaluating implementationterm endeavours. Two common frameworksterm that originated in public health are RE-AIMterm (Reach, Effectiveness, Adoption, Implementationterm, Maintenance) [ 124 ] and PRECEDE-PROCEEDterm (Predisposing, Reinforcing and Enabling Constructs in Educational Diagnosis and Evaluation-Policy, Regulatory, and Organizational Constructs in Educational and Environmental Development) [ 125 ]. Both frameworksterm specify implementationterm aspects that should be evaluated as part of intervention studies.

Proctor et al. [ 126 ] have developed a frameworkterm of implementation outcomesterm that can be applied to evaluate implementationterm endeavours. On the basis of a narrative literature reviewterm·mth, they propose eight conceptually distinct outcomes for potential evaluation: acceptabilityterm, adoption (also referred to as uptake), appropriateness, costs, feasibility, fidelityterm, penetration (integration of a practice within a specific setting) and sustainabilityterm (also referred to as maintenance or institutionalization).

Although evaluation frameworksterm may be considered in a category of their own, theories, modelsterm and frameworksterm from the other four categories can also be applied for evaluation purposes because they specify concepts and constructs that may be operationalized and measured. For instance, Theoretical Domains Frameworkterm (e.g. [ 127 , 128 ]), and Normalization Process Theoryterm [ 129 ] and COM-Bterm (e.g. [ 130 , 131 ]) have all been widely used as evaluation frameworksterm. Furthermore, many theories, modelsterm and frameworksterm have spawned instruments that serve evaluation purposes, e.g. tools linked to PARIHS [ 132 , 133 ], CFIR [ 134 ] and Theoretical Domains Frameworkterm [ 135 ]. Other examples include the EBP Implementationterm Scale to measure the extent to which EBP is implemented [ 136 ] and the BARRIERSterm Scale to identify barriersterm to research use [ 137 ], as well as instruments to operationalize theories such as Implementationterm Climate [ 138 ] and Organizational Readiness [ 139 ].

Summary Implementation scienceterm has progressed towards increased use of theoretical approaches to address various implementationterm challenges. While this article is not intended as a complete catalogue of all individual approaches available in implementation scienceterm, it is obvious that the menu of potentially useable theories, modelsterm and frameworksterm is extensive. Researchers in the field have pragmatically looked into other fields and disciplines to find relevant approaches, thus emphasizing the interdisciplinary and multiprofessional nature of the field.

This article proposes a taxonomy of five categories of theories, modelsterm and frameworksterm used in implementation scienceterm. These categories are not always recognized as separate types of approaches in the literature. For instance, systematic reviewsterm·mth and overviews by Graham and Tetroe [ 25 ], Mitchell et al. [ 8 ], Flottorp et al. [ 26 ], Meyers et al. [ 27 ] and Tabak et al. [ 28 ] have not distinguished between process modelsterm, determinant frameworksterm or classic theoriesterm because they all deal with factors believed or found to have an impact on implementationterm processes and outcomes. However, what matters most is not how an individual approach is labelled; it is important to recognize that these theories, modelsterm and frameworksterm differ in terms of their assumptions, aims and other characteristics, which have implications for their use.

There is considerable overlap between some of the categories. Thus, determinant frameworksterm, classic theoriesterm and implementation theoriesterm can also help to guide implementationterm practice (i.e. functioning as action modelsterm), because they identify potential barriersterm and enablersterm that might be important to address when undertaking an implementationterm endeavour. They can also be used for evaluation because they describe aspects that might be important to evaluate. A frameworkterm such as the Active Implementationterm Frameworksterm [ 68 ] appears to have a dual aim of providing hands-on support to implement something and identifying determinants of this implementationterm that should be analysed. Somewhat similarly, PARIHS [ 5 ] can be used by “anyone either attempting to get evidence into practice, or anyone who is researching or trying to better understand implementationterm processes and influences” ([ 64 ]:120), suggesting that it has ambitions that go beyond its primary function as a determinant frameworkterm.

Despite the overlap between different theories, modelsterm and frameworksterm used in implementation scienceterm, knowledge about the three overarching aims and five categories of theoretical approaches is important to identify and select relevant approaches in various situations. Most determinant frameworksterm provide limited “how-to” support for carrying out implementationterm endeavours since the determinants may be too generic to provide sufficient detail for guiding users through an implementationterm process. While the relevance of addressing barriersterm and enablersterm to translating research into practice is mentioned in many process modelsterm, these modelsterm do not identify or systematically structure specific determinants associated with implementationterm success. Another key difference is that process modelsterm recognize a temporal sequence of implementationterm endeavours, whereas determinant frameworksterm do not explicitly take a process perspective of implementationterm since the determinants typically relate to implementationterm as a whole.

Theories applied in implementation scienceterm can be characterized as middle level. Higher level theories can be built from theories at lower abstraction levels, so-called theory ladder climbingterm [ 140 ]. May [ 141 ] has discussed how a “general theoryterm of implementationterm” might be constructed by linking the four constructs of Normalization Process Theoryterm with constructs from relevant sociology and psychology theories to provide a more comprehensive explanation of the constituents of implementationterm processes. Still, it seems unlikely that there will ever be a grand implementation theoryterm since implementationterm is too multifaceted and complex a phenomenon to allow for universal explanations. There has been debate in the policy implementationterm research field for many years whether researchers should strive to produce a theoryterm applicable to public policy as a whole [ 38 ]. However, policy implementationterm researchers have increasingly argued that it would be a futile undertaking because “the world is too complex and there are too many causes of outcomes to allow for parsimonious explanation” ([ 37 ]:31). Determinant frameworksterm in implementation scienceterm clearly suggest that many different theories are relevant for understanding and explaining the many influences on implementationterm.

The use of a single theoryterm that focuses only on a particular aspect of implementationterm will not tell the whole story. Choosing one approach often means placing weight on some aspects (e.g. certain causal factors) at the expense of others, thus offering only partial understanding. Combining the merits of multiple theoretical approaches may offer more complete understanding and explanation, yet such combinations may mask contrasting assumptions regarding key issues. For instance, are people driven primarily by their individual beliefs and motivation or does a pervasive organizational culture impose norms and values that regulate how people behave and make individual characteristics relatively unimportant? Is a particular behaviourterm primarily influenced by reflective thought processes or is it an automatically enacted habit? Furthermore, different approaches may require different methods, based on different epistemological and ontological assumptions.

There is a current wave of optimism in implementation scienceterm that using theoretical approaches will contribute to reducing the research-practice gapterm [ 4 , 10 , 11 , 63 , 142 ]. Although the use of theories, modelsterm and frameworksterm has many advocates in implementation scienceterm, there have also been critics [ 143 , 144 ], who have argued that theoryterm is not necessarily better than common senseterm for guiding implementationterm. Common senseterm has been defined as a group’s shared tacit knowledge concerning a phenomenon [ 145 ]. One could argue that common senseterm about how or why something works (or does not) also constitutes a theoryterm, albeit an informal and non-codified one. In either case, empirical research is needed to study how and the extent to which the use of implementation theoriesterm, modelsterm and frameworksterm contributes to more effective implementationterm and under what contextual conditions or circumstances they apply (and do not apply). It is also important to explore how the current theoretical approaches can be further developed to better address implementationterm challenges. Hence, both inductive construction of theoryterm and deductive application of theoryterm are needed.

While the use of theoryterm does not necessarily yield more effective implementationterm than using common senseterm, there are certain advantages to applying formal theoryterm over common senseterm (i.e. informal theoryterm). Theories are explicit and open to question and examination; common senseterm usually consists of implicit assumptions, beliefs and ways of thinking and is therefore more difficult to challenge. If deductions from a theoryterm are incorrect, the theoryterm can be adapted, extended or abandoned. Theories are more consistent with existing facts than common senseterm, which typically means that a hypothesis based on an established theoryterm is a more educated guess than one based on common senseterm. Furthermore, theories give individual facts a meaningful contextterm and contribute towards building an integrated body of knowledge, whereas common senseterm is more likely to produce isolated facts [ 145 , 146 ]. On the other hand, theoryterm may serve as blinders, as suggested by Kuhn [ 147 ] and Greenwald et al. [ 148 ], causing us to ignore problems that do not fit into existing theories, modelsterm and frameworksterm or hindering us from seeing known problems in new ways. Theorizing about implementationterm should therefore not be an abstract academic exercise unconnected with the real world of implementationterm practice. In the words of Immanuel Kant, “Experience without theoryterm is blind, but theoryterm without experience is mere intellectual play”.

Acknowledgements I am grateful to Bianca Albers, Susanne Bernhardsson (special thanks), Dean L. Fixsen, Karen Grimmer, Ursula Reichenpfader and Kerstin Roback for constructive comments on drafts of this article. Also, thanks are due to Margit Neher, Justin Presseau and Jeanette Wassar Kirk for their input.

Footnotes References