Defining Fidelity Categories When Implementing Reading Interventions

Teacher being checked for fidelity

When a teacher is checked for fidelity of a reading intervention, a rubric can help to ensure structural and procedural fidelity are included on both global and lesson-specific levels.


Posted on: July 31, 2018

Editor’s Note: This is the second of a multi-part series on defining, measuring, and using fidelity to improve literacy instruction.

In a previous post, we introduced the concept and importance of fidelity when implementing reading interventions. In this context, we are defining fidelity as how closely the implementation of a literacy intervention is aligned to the way the intervention was designed. Given that interventions may include many parts, there are different ways to think about fidelity, and even researchers struggle with defining and measuring the concept (Harn, Damico, & Stoolmiller, 2017; Harn, Parisi, & Stoolmiller, 2013).

In this post we will go into more detail on two important categories of fidelity: structural fidelity and procedural fidelity (sometimes referred to as process fidelity; Harn et al., 2017; Harn et al., 2013). We also will discuss the differences between global fidelity and lesson-specific fidelity (National Center on Early Childhood Development, Teaching, and Learning, 2016).

Structural Fidelity

Structural fidelity is a traditional and more simplistic view of fidelity. It measures if a teacher has adhered to an intervention by using the materials for the recommended time per session (e.g., 30 minutes), number of sessions (e.g., 15 sessions), or intervention duration (e.g., full academic year). It also measures to what extent students have been exposed to specific intervention components (e.g., 30 minutes of small group and 60 minutes of whole class). Example guiding questions addressing structural fidelity include:

  • Were the important pieces of the intervention delivered?
  • Was the instruction consistent with the scope and sequence of the intervention?
  • Did students receive the recommended amount and types of instruction?

If an administrator is only interested in structural fidelity, they may simply check to see how many of the intervention materials or lessons are used and how often. This type of fidelity can be checked by reviewing a teacher's instructional logs and lesson plans, and it requires the administrator to have good familiarity with the intervention components and requirements.

Procedural Fidelity

Procedural fidelity measures the manner in which the teacher delivers the intervention using the techniques, processes, or methods prescribed by the intervention. In addition, it measures the quality of the intervention delivery and student responsiveness or engagement during those lessons. Example guiding questions to address procedural fidelity include:

  • What was the nature of the delivery and teacher/student interactions?
  • Did the teacher provide the instruction in the manner expected?
  • Did the students follow the directions and complete the activities as expected?

Research findings suggest that procedural fidelity has a stronger relation to student outcomes than structural fidelity (Capin, Walker, Vaughn, & Wanzek, 2017). If an administrator is interested in procedural fidelity, he or she would need to observe the teacher conducting the intervention and compare to the recommendations from the intervention developer.

Global Fidelity Versus Lesson-Specific Fidelity

The differences between global and lesson-specific fidelity are important to understand in order to fully grasp the overall concept of fidelity (National Center on Early Childhood Development, Teaching, and Learning, 2016). Global fidelity addresses the intervention big picture and is tied to the guiding principles or learning theories that drive the intervention. Lesson-specific fidelity addresses the smaller chunks of the intervention such as specific activities or lesson components. Both global and lesson-specific fidelity involve aspects of structural and procedural fidelity. For example, across the entire observation, a teacher may have used the assigned curriculum for the right amount of time (global structural fidelity) using direct and explicit instruction (global structural fidelity). However, the teacher may have skipped parts of the whole-group lesson (lesson-specific structural fidelity) or did not use the intervention’s suggested examples during small-group instruction (lesson-specific procedural fidelity).

Illustrated Example of Defining Fidelity

Recall in the previous blog post on this topic, we provided the example of two teachers who were asked to implement a new core reading curriculum as an intervention. When the instructional coach asked about the teachers’ fidelity, one teacher reported implementing the curriculum’s whole-group and small-group instruction every day for the full 90-minute literacy block. The other teacher reported implementing the curriculum’s whole-group instruction for 60 minutes and using other materials for small-group instruction for the remaining 30 minutes. Only addressing structural fidelity, the coach determined that the first teacher had higher fidelity than the second teacher.

Although this is better than not checking fidelity at all, there is room for improvement. The coach can develop a fidelity rubric that addresses both structural and procedural fidelity, and look for both global and lesson-specific items. The coach can share the rubric with the teachers, encourage them to reflect on their implementation, identify how they could improve their fidelity, and schedule follow-up observations. In Figure 1, we display how lesson-specific and global fidelity are related, and how structural and procedural fidelity can be considered in both areas relative to the example above.

Figure 1. Example Fidelity Rubric for a Literacy Intervention

Figure 1. Example Fidelity Rubric for a Literacy Intervention

To further illustrate the types of items an administrator may look for when checking an instructor’s fidelity, we have provided an Example Fidelity Rubric below in the “Supplemental Materials for Teachers” section.

Defining the different categories of fidelity is the first step, but more preparation needs to happen before conducting fidelity observations and determining what to do with the data collected. In the next blog post in this series, we will address how to create an instrument and the process for measuring the fidelity of your implemented intervention.

Supplemental Materials for Teachers

PDF iconExample Fidelity Rubric

This is an example of a fidelity rubric that addresses both structural and procedural fidelity at the global and lesson-specific levels. Note that this example fidelity rubric does not correspond with a specific intervention, curriculum, or practice. Rather, we have created example items that may correspond with a range of reading interventions. It is not intended to be used as an actual fidelity rubric because it does not correspond with a specific intervention.


Capin, P., Walker, M. A., Vaughn, S., & Wanzek, J. (2017). Examining how treatment fidelity is supported, measured, and reported in K-3 reading intervention research. Educational Psychology Review. doi:10.1007/s10648-017-9429-z

Harn, B. A., Damico, D. P., & Stoolmiller, M. (2017). Examining the variation of fidelity across an intervention: Implications for measuring and evaluating student learning. Preventing School Failure: Alternative Education for Children and Youth, 61, 289–302. doi:10.1080/1045988X.2016.1275504

Harn, B. A., Parisi, D., & Stoolmiller, M. (2013). Balancing fidelity with flexibility and fit: What do we really know about fidelity of implementation in schools? Exceptional Children, 79, 181–193. doi:10.1177/001440291307900204

National Center on Early Childhood Development, Teaching, and Learning (2016). Curriculum implementation fidelity. Washington, DC: U.S. Department of Health & Human Services, Administration for Children & Families, Head Start Early Childhood Learning & Knowledge Center. Retrieved from