What type of evaluation do I need?

Qualitas Research

What type of evaluation do you need?

A typical question in early conversations with clients is the type of evaluation that will be most helpful. 

You have likely heard of a few different kinds of evaluation. There are quite a few! In this article we will take a quick look at some of the more common ones, and think about the different ways each can help.

What we'll cover

  • Formative and summative evaluations
  • Process, outcome and impact evaluations
  • What will formative evaluation help you with?
  • What will summative evaluation help you with?
  • What type of evaluation do you need?


Let’s first consider the basic distinction.

Formative and summative evaluations

When thinking about different types of evaluation, we often distinguish between formative and summative evaluations. Formative literally means “serving to form something”. It refers to the things that influence a program’s development. Summative basically means “the sum of all things learned”.

We can see from this that formative evaluation will be early in the process of something, to learn about processes and development. Summative evaluation will be towards the end of the process, to learn about the effects, or results, of something.

So, what distinguishes them is when the evaluation is carried out. A formative evaluation is carried out when a new initiative is being developed, or when an existing one is being adapted. A summative evaluation is carried out when an initiative is well established.

A different focus

Formative and summative evaluations have a different focus. There are typically differences in the kinds and frequency of data collected, and how and when the findings are reported.

Table describing the differences between formative and summative evaluations

Process, outcome and impact evaluations

What about the other common types of evaluation – process, outcome, and impact evaluation? How do these relate to the formative / summative distinction?

This diagram shows how they all fit together.

Diagram of formative and summative evaluations

Within the two groupings of formative and summative, there are different types of evaluation. Typically, formative evaluation considers the need for an initiative (needs assessment), or its implementation (process evaluation). Summative evaluation assesses short to medium-term outcomes (outcome evaluation) and longer-term impact (impact evaluation).

Table of types of evaluation

What will formative evaluation help you with?

Formative evaluation provides information you can use to improve your project, service, or other initiative. It involves assessing design, implementation and delivery. It focuses on the views and experiences of the people participating in the project. It will identify any weaknesses or problems so these can be acted on. It helps ensure your initiative is feasible and appropriate before you go ahead and fully implement it.

What will summative evaluation help you with?

Summative evaluation tells you about the effectiveness, outcomes or impact of your initiative. It typically assesses the extent to which your project or service achieves its goals and objectives. It will provide evidence of how it benefits people. This will be useful for future planning, and can support applications for funding for further development.

What type of evaluation do you need?

An evaluation can be one of these types, or a combination of them. This depends on the stage of your program or project, and what you want to learn. Most evaluations I have carried out are process and outcome evaluations (sometimes combined), with the odd needs assessment thrown in. Impact evaluations are, sadly, less common – most likely because resources might not allow for long-term follow up.

If you have not yet started your initiative, you want a needs assessment to gather information about the extent of the need for your intended project or service. This can help ensure your initiative is the best way to go about meeting a clearly defined need. This also provides helpful evidence to apply for funding to set up a project. Useful, right?

If you are early in the process of developing your service or project, you can do a process evaluation to help you learn how well it is being implemented, and detect any problems requiring action. Picking up on weaknesses at an early stage will help you avoid bigger problems emerging in the long run. Sounds good, doesn’t it?

If your initiative is up and running, an outcome evaluation will help you understand the short and medium-term effects of your service on the people participating in it. You can share your successes, and gather evidence for future development. Don’t leave it right to the end though, it’s always a good idea to start planning early on! This way we can collect the most useful data to make good outcome assessments. 

An impact evaluation is carried out much further down the road, and will reveal the longer-term effects of your initiative on your target population and the wider community. In an ideal world, we’d all be doing impact evaluations – I know I would. How awesome would it be to know the long-term effects of your work on the community!

Summary: Common types of evaluation

In this article we covered:

  • What are formative and summative evaluations?
  • Process, outcome and impact evaluations
  • What will formative evaluation help you with?
  • What will summative evaluation help you with?
  • What type of evaluation do you need?

Want to read more?

We hope you found this article useful. For more information, check out our other articles about evaluation – there’s one about what evaluation is and how it can help, and another about how to increase the use of evaluations. You can also follow us on Facebook to hear about our latest posts. If you need an evaluator, please get in touch.

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