Choose your approach to data collection

The cycle of good impact practice:  Which approaches are most suited to your needs?

Here we look at the different ways in which you can collect data.  Broadly, the data you collect will fall into one of two categories:

  • Quantitative data (numbers) helps answer the questions what, who, where and how many? The results of quantitative data allow you to make numerical statements about the prevalence of views, attitudes and experiences, to measure difference between sample groups over time, and to establish patterns and causal links. Surveys are often used to collected quantitative data.
  • Qualitative data (stories) seeks to understand in depth why and how change happens. This allows you to understand a full range of answers and underpinning factors. Examples of qualitative approaches include in-depth interviewing and observation.

When it comes to impact practice, both qualitative and quantitative data should be used side by side, and ideally with equal importance. We think this is best reflected by a saying we have at NPC: ‘no numbers without stories, no stories without numbers’.

Quantitative and qualitative methods of data collection are often pitted against each other, but they have different, complementary uses:

Quantitative data (numbers) Qualitative data (stories)
  • Provides a clear message which is quick and easy to understand.
  • Helps organisations assign costs and benefits of certain results.
  • Uncovers links between subgroups of data—for example, how Groups 1 or 2 benefitted from X or Y service.
  • Can reduce bias in data through large number of people taking part.
  • Captures complexities of social change—especially for beneficiaries.
  • Provides in-depth understanding of areas where services can be improved.
  • Resists reducing information down to its simplest form, offering a greater variety of data.
  • Produces highly detailed information from a range of stakeholders.


Consider the needs of your organisation, those you work with and your stakeholders before deciding on the best way to collect data. Below are some factors to consider when choosing your data collection approaches:

  • Depth of information required – Are you looking for in-depth stories (qualitative data) or numbers (quantitative data), or a combination of the two?
  • Type of information required – different approaches are helpful to answer different types of questions. For example, observations can provide insights into an unfamiliar setting or group of people to inform initial programme design or to understand how people are experiencing your service. Creative methods and focus groups are useful to explore different views and perspectives on a topic. Surveys are useful for collecting systematic data that can be used to compare participants knowledge, attitudes and skills before and after accessing your support.
  • Sensitivity and complexity of the issues – Do you need information on sensitive or complex issues such as people’s lifestyle choices or behaviours? Consider which method will be appropriate for asking questions on these. Will participants be willing to discuss these topics in a one-to-one interview or will an anonymous survey be more suitable?
  • Time – Consider how much time you will be asking of people taking part in your data collection activities, and whether this is realistic and proportionate depending on the nature of contact you have had with them. Short surveys can be useful when time is limited and allow people to complete them in their own time.
  • Ease of collection and analysis – Think about how straightforward it will be for you to collect and analyse data. Interviews and focus groups are likely to be more complex to record and analyse, but you may decide it’s important to spend time on this if it gives you the most useful data.
  • Accessibility – can your target audience access and meaningfully engage with the data collection approaches you are considering? How might you adapt your methods to ensure this is the case?

Adapted from content by NCVO and our briefing on collecting the right impact data.

The following pages provide further information on specific approaches to data collect, including strengths and weaknesses, to help you find the approaches that best meet your needs.


The cycle of good impact practice defines what impact practice is and articulates a clear path to success. It follows a four-step cycle. This page is part of Do, the second step in the cycle.

Other resources from this step in the cycle

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This webpage has been adapted from the Inspiring Impact programme, which ran from 2011 until early 2022 and supported voluntary organisations to improve their impact practice. More information about the Inspiring Impact programme.