Guest post by Von Jessee, M.A.
Program Specialist for Research and Evaluation
Help Me Grow National Center

The Help Me Grow® (HMG) system began as a single pilot program in Hartford, Connecticut in 1997. When the Commonwealth Fund supported the initial replication of the HMG model in Orange County, California, the original HMG leadership had the opportunity review and identify the critical components essential ensuring developmental promotion, early detection, and referral and linkage to services within larger early childhood systems.

Through this scaling process, we identified four core components and three structural requirements as necessary elements to achieve both early identification of concerns and timely connection to services for all families. It is this model that the HMG National Center (HMG National) now uses for national replication. The elements to this model are as follows:


  • Healthcare Provider Outreach
  • Family & Community Outreach
  • Centralized Access Point
  • Data Collection & Analysis


  • Organizing Entity
  • Strategy for Statewide Expansion
  • Continuous Quality Improvement

As each core component and structural requirement plays a critical role in the identification and linkage process, fidelity to these elements is essential for any model to truly function as HMG

In this blog, I approach fidelity and HMG from three angles. First, I unpack the meaning of model fidelity, as the concept is often difficult to pin down.

Second, I explore how system-level models like HMG need fidelity just as much as targeted intervention models, and how system-level models must balance fidelity with flexibility.

Third, I make the case for the critical importance of fidelity in system-building from planning to sustainability.


I say “fidelity,” you hear…

Typically, the concept of fidelity is used to assess whether or not a model is operating as intended at the point of implementation. But what is fidelity, really?

Existing research characterizes fidelity across five dimensions: adherence, exposure, quality of delivery, participant responsiveness, and program differentiation. These dimensions reflect how, to whom, and to what degree a particular intervention is delivered.[1] In practical terms, fidelity is commonly measured by the content of program activities, amount of activities delivered, how participants engage in the program, and identifying the critical components necessary for delivery.

Health services and targeted intervention models commonly use the word “fidelity” to describe successful adherence to the original intent and design of a model. In targeted intervention models that work to promote positive outcomes in children (e.g. the Nurse-Family Partnership or Centering Parenting), fidelity is defined and evaluated around a concrete set of criteria that ensure the delivery of services as anticipated.

Such clearly defined criteria allow for program implementation in an ever-growing number of sites with the assurance of serving the identified population through a reliable method. Similarly, the idea of model fidelity can apply to system models at the local, state, or national level.


Does fidelity apply to system-level models?

The concept of fidelity assessment differs between system-level models and targeted intervention models in two areas: the key assessment metrics and the model placement. Typically, system-level models are under greater pressure to balance flexibility with fidelity in these two areas.

(To clarify, targeted intervention models address a recognized need of an identified population within a specific setting. System-level intervention models, however, such as MIECH-V, Build Initiative, HMG, achieve a specific purpose by supporting or facilitating activities among existing programs, services, and initiatives.)

1. Key Assessment Metrics

A targeted intervention model will likely have a set of concrete, key assessment metrics around elements such as target demographics, priority content, and the vehicle for delivery.

A system-level model, on the other hand, must use high-level assessment metrics that define the key components of the system model, while remaining flexible enough to fit these components within the larger early childhood system.

A system-level model also implies that fidelity must be viewed across multiple delivery settings as opposed to a single program or entity. Therefore, fidelity must be assessed not only in terms of delivery, but also with an emphasis on the collaboration across sectors that are required with a system level model such as HMG.

2. Model Placement

A targeted intervention model and a system-level model also have distinctive characteristics regarding their placement within the greater early childhood system. For targeted intervention models, the initiative must be well-defined and compact, so that the model can be seamlessly placed in the existing organization’s infrastructure or the surrounding community. Each targeted intervention model is likely addressing a specific need or population within a site or community.

A system-level model, while having its well-defined priorities and features, must remain broad enough to embrace the community’s services and fit into the larger state or national early childhood system.

For example, HMG has clear components and structural requirements, but leaves the organizing of roles and funding streams for each state or community to define. System-level models must have a flexible frame that supports a foundation appropriate for each state or community’s unique needs. Fidelity must match this flexibility by focusing on the broader features that connect these components and support the system.

HMG matches fidelity and flexibility by defining the key activities of each component and how the components will interact, yet leaves the approach to the discretion of the state. Take the Centralized Access Point core component. Each HMG must have a centralized telephone access point to achieve fidelity to the model. However, identifying the appropriate hosting entity, the approach to attain statewide reach, and the resource database can be determined by the HMG affiliate to fit into the specific community and utilize its existing resources.


How fidelity supports system-building — and should from the start

Traditionally, targeted intervention models use fidelity to measure the degree to which the delivery of a model in new settings adheres to the original model. This has been an incredibly useful tool to ensure the implementation of a model as intended and using the approach proven to be most effective.

Broader system building efforts can benefit just as powerfully from fidelity models. Like targeted interventions, system-building efforts like HMG operate on key ideas that ensure optimal impact. If each component is not implemented in accord, a system-level model will fail to be effective and will call into question the efficacy of the original model.

The most useful fidelity models clearly define the high-level components vital for optimal impact. They define fidelity assessment measures that consider the key activities of each component, and they articulate this model as the standard of any future dissemination. For HMG, such a fidelity model will help states, communities, and entities achieve both early identification of concerns and timely connection to services for all families.

However, a model is not effective if it is used as a backward-looking process. After all, carpenter doesn’t check the blueprints after the house is built! Instead, the concept of fidelity should be used to inform the process of model development — from model exploration to sustainability. Here’s what that process can look like:

·       During planning, states, communities, or entities can use the fidelity model to help identify the necessary components, the activities within those components, and the connections between them.

·       During implementation, entities can use the fidelity model to build sustainability by securing the model’s foundation over time.

·       As entities turn toward establishing sustainability, adhering to the fidelity model ensures accountability while enabling expansion and enhancement of the model through innovation.

In short, fidelity is the core of system-building efforts that seek to replicate and expand evidence-informed and/or evidence-based models. In the case of HMG, fidelity confirms the replication of the core components and structural requirements that enable successful implementation and optimal impact.

[1] Dusenbury L, Brannigan R, Falco M, Hansen WB. A review of research on fidelity of implementation: implications for drug abuse prevention in school settings. Health Education Research. 2003;18(2):237-256.