Understanding Impact and Evaluation Foundations

This lesson explains what impact means and how evaluation helps people make better decisions. Drawing on W1_2_Evaluation_Foundations_Handouts_material_for_IMPACT_82466778, impact is not just a general idea of “making a difference.” It is a specific way of thinking about change in outcomes for people or the planet.

What is impact?

According to W1_2_Evaluation_Foundations_Handouts_material_for_IMPACT_82466778, impact is a change in outcomes for people or the planet. These outcomes can involve things like health, poverty, employment, behavior, information flows, thinking, or environmental conditions.

The source also emphasizes that impact is:

• Dynamic — it can change over time.
• Multifaceted — it often includes multiple outcomes at once.
• Socially constructed — definitions may differ, though a broader consensus is emerging.

Impact can be positive or negative

Impact is not always good. The source explains that we must ask: What outcome occurs? Is it positive or negative? How important is it to the stakeholders experiencing it? This means impact includes both:

• Positive change, such as improved health or reduced poverty.
• Negative change, such as environmental damage or increased hardship.

In other words, an action may help some stakeholders while harming others. A full understanding of impact requires looking at both sides.

Impact can be intended or unintended

W1_2_Evaluation_Foundations_Handouts_material_for_IMPACT_82466778 states that impact may be intended or unintended. Organizations often plan for certain results, but additional effects can appear that were not expected.

• Intended impact is the change a program or organization aims to create.
• Unintended impact is change that happens without being planned.

Unintended impacts can also be positive or negative, so they are important to monitor and assess.

Impact is experienced by different stakeholders

The source introduces key dimensions of impact, including who experiences the outcome and how much change occurs. Stakeholders may include humans and nonhuman nature. This matters because changes in ecosystems or species can indirectly affect people as well.

Important questions include:

• Who is experiencing the outcome?
• How underserved are they in relation to that outcome?
• How many stakeholders are affected?
• How large is the change?
• How long does it last?

Impact can change over time

A major lesson from W1_2_Evaluation_Foundations_Handouts_material_for_IMPACT_82466778 is that impact is not fixed. The source notes that impact is an amalgam of outcomes and that it can shift over time, even turning from positive to negative or from negative to positive for a given stakeholder.

The dam construction example in the source shows this clearly:

• Some city residents experienced positive outcomes such as cleaner energy and lower unemployment.
• Some village residents experienced short-term gains followed by long-term decline in soil fertility and poverty.
• The natural environment experienced serious negative outcomes, including loss of species.

This example shows that impact is rarely a simple yes-or-no judgment. Different groups may experience different effects, and those effects may change across years.

Key dimensions for understanding impact

W1_2_Evaluation_Foundations_Handouts_material_for_IMPACT_82466778 presents several dimensions that help analyze impact:

• What — What outcome occurs, and is it positive or negative?
• Who — Which stakeholders experience the outcome?
• How much — How many experience it, how deep is the change, and how long does it last?
• Contribution — Is the change better than what would have happened otherwise?
• Risk — Was the change expected or unexpected?

These dimensions help move from vague claims about impact to a more careful assessment of real-world change.

What is the role of evaluation?

Evaluation helps people understand programs and actions so they can take action and make decisions. In W1_2_Evaluation_Foundations_Handouts_material_for_IMPACT_82466778, the value of evaluation is linked to its usefulness to improve effectiveness. This means evaluation is not only about collecting information. It is about informing choices.

Evaluation draws on research when relevant. The source explains that if strong research already shows a causal relationship, evaluation may not need to re-prove it. Instead, it can focus on whether the program delivered the relevant activities or reached the intended people.

Formative and summative evaluation

The source distinguishes two common types of evaluation:

• Formative evaluation — used to improve delivery of a project, program, or intervention. It focuses on activities, outputs, and short-term outcomes, helping teams make mid-course adjustments.
• Summative evaluation — used at the end of a program to assess effectiveness or impact. It focuses more on results and can support accountability, demonstration of value, and scaling decisions.

Both types inform action, but they do so in different ways. Formative evaluation supports improvement during implementation, while summative evaluation supports judgments about results and effectiveness.

Monitoring and management

W1_2_Evaluation_Foundations_Handouts_material_for_IMPACT_82466778 also connects evaluation to monitoring and management:

• Impact monitoring is continuous.
• It focuses on outcomes and whether intended impact is likely to occur.
• It should identify unintended outcomes, both positive and negative.
• It can be used at project, program, or organization level.

Impact management then uses evidence from evaluation and monitoring to support decision making. In other words, evaluation informs action, and management responds based on what the evidence shows.

Key takeaways

• Impact means change in outcomes for people or the planet.
• Impact can be positive or negative.
• Impact can be intended or unintended.
• Impact may differ across stakeholders and change over time.
• Evaluation helps people improve programs, assess results, and make decisions.
• Formative evaluation supports improvement during delivery, while summative evaluation assesses effectiveness or impact.
• Monitoring and management use evidence to guide ongoing action.