Understanding Formative and Summative Evaluation: What Does Your Program Need?

Whether you're new to evaluation or have already been using evaluation methods, you'll likely encounter two key terms: "formative evaluation" and "summative evaluation." If these concepts are new to you, this is a great introduction.

Early evaluation practitioner, Bob Stake, uses this simple analogy:

"When the cook tastes the soup, that's formative; when the guests taste the soup, that's summative."

Both formative and summative evaluation serve important purposes, yet work quite differently in practice. Let's examine how each type differs and can benefit your program.

The Key Differences

Formative Evaluation:

Think of formative evaluation as continuous monitoring - (going back to Stake’s analogy) - it’s the cook tasting of the soup several times to adjust the seasoning. In program terms, this could mean checking if program activities are working as intended and adjusting as needed. Formative evaluation also includes planning for a program’s implementation – think needs assessments and feasibility assessments.

Summative evaluation:

On the other hand, summative evaluation tells the story of what your program accomplished – it’s the guests sharing their final thoughts after their meal. For programs, this could translate to figuring out whether you met your objectives or identifying the impact you had on your program participants.

Here's another practical breakdown of how they differ as summarized

by Herman (1987):

Audience

• Formative: Program developers, implementors, or managers

• Summative: Organizational leaders, funders or policy makers

Information Collected

• Formative: Data and/or information on processes, implementation, outputs and progress towards goals/objectives

• Summative: Output and outcome data demonstrating program impact

Reporting Frequency

• Formative: Ongoing reports to enable quick program adjustments

• Summative: Usually one comprehensive report at program conclusion

Which Type Does Your Program Need?

Most programs benefit from both types of evaluation rather than zeroing on just one. The key is finding the right balance for your resources and needs as a program.

Consider these scenarios:

• New program trying to better serve your clients? Start with formative evaluation so you can collect information that informs the program’s design before the program is actually implemented. Then continually monitor the program’s implementation.

• Established program wanting to share your success? Use summative evaluation to show your proven impact.

• Innovative program wanting to showcase your work to funders? Consider combining both approaches to capture your program’s development and its potential for impact.

Is Formative Evaluation the Same Thing as Process Evaluation?

In short, no. Both process evaluation and formative evaluation monitor how a program is being implemented. But formative evaluation does much more. Think of formative evaluation as the umbrella under which process evaluation stands. You will need to do process evaluation to know HOW your program was implemented. Process evaluation is specific to monitoring the current implementation of a program. Without this information, a summative evaluation will fall short – you won’t know why the impact occurred (or not). Formative evaluation does this, in addition to the planning activities that help design the program before its implementation.

Are you ready to develop one of these evaluation approaches that works for your program? Our team at Strategic Prevention Solutions specializes in helping organizations create practical, effective evaluation strategies. Contact us to get started today!