Questionnaire (& structured interview)

A method of data collection in which each person is asked to respond to the same set of questions in a predetermined order. It therefore includes both face-to-face and telephone questionnaires as well as those in which the questions are answered without an interviewer being present, such as paper and online questionnaires. It is most frequently used  to answer ‘what’, ‘who’, ‘where’, ‘how much’ and ‘how many’ questions. It allows the collection of standardised data from a sizeable population in a highly economical way, allowing easy comparison. The collected quantitative data can be analysed using statistical methods, used to suggest possible reasons for particular relationships between variables and to produce models of these relationships. Questionnaires can be on paper, online, or as structured interviews (Saunders et al., 2016). It is advisable to conduct semi-structured interviews prior to designing and conducting a questionnaire, to devise the set of meaningful questions for the questionnaire and ensure that the questions are interpreted the same way by all respondents.

Basic Information on the Method
Mode of communication
Face-to-face, Both
Group size
31 and more
Geographical scale
Public space, Neighbourhood, City, Region
Skills required
Resources needed
Level of Involvement
Level of involvement
Type of knowledge enabled
Divergence (Broad public)
Additional Criteria
Planning phase
Initiatiion, Planning & Design, Evaluation & Research, Maintenance
Methodological approach

How to use the method

  1. Decide what kind of information do you need, whom do you want to ask (target population) and how do you want to ask (on paper, online or as a structured interview).
  2. Calculate the optimum sample size. Note, that the sample size depend on the size of you target population. The smaller is the population, the larger is the optimum sample in relation to the population. As a rule of thumb for statistical analysis a number of 30 is the smallest number for the target population. Consider the response rate, which may vary dramatically from 10 to 50% for postal and online questionnaires and to 90% for face-to-face structured interviews.
  3. Develop a set of questions. With large samples it is advisable to use close-ended questions, which may be analysed with statistical tools. Close-ended questions include multiple-choice questions, ranking questions (e.g., importance from 1 to 5), rating question (e.g., from agree to disagree), quantity questions and matrix questions.
  4. Test the questions with a small sample, to ensure that participants understand the questions and possible answers in the way you intended. If needed, revise the questions and possible answers.
  5. Print out the questionnaires (postal questionnaire) or upload the questionnaire to the online platform (online questionnaire). For online questionnaire you may use Google Forms (free), Webropol (paid) or their alternatives.
  6. Make the list of participants, contact them and ask to answer the questionnaire. Give them sufficient time to return the questionnaires (from a couple of weeks to a couple of months). If needed, send them reminders.
  7. Collect the questionnaires and analyse the results with statistical tools. To give a richer understanding of the phenomenon in focus, questionnaires may be combined with interviews or observations.

What are the outcomes

Numerical data from a representative sample of population, which can be depicted visually using charts. The data usually indicates if the initial propositions related to the target population are true or false, and suggest the correlations between different variables.

Skills required

Skills required from participants - Basic

  • Questionnaires are intended to gather information from lay population about their activities, opinions, values, etc., therefore, no specific knowledge or skills are required.

Resources needed

Resources - Medium

  • The resourced vary depending on the number of respondents, the length of a questionnaire and the collection methods (paper, online, interview)
  • On average it takes a couple of weeks to develop, test and revise the set of questions, a couple of weeks to make the list of participants and to contact them, and a couple of months to collect the filled in questionnaires. Analysis of the postal questionnaires might take another couple of months
  • Expenses related to the use of online tools
  • Expenses related to printing, sending and collecting postal questionnaires. A return postage label should be enclosed
  • It is useful to hire a researcher, who is trained in designing, conducting and analysing surveys

Strengths and weaknesses

  • Produces the data which is easy to quantify and visualise
  • Quantitative data is perceived by many stakeholders as reliable
  • Low response rates
  • Respondents interpret questions in different ways
  • Quantitative data gives the idea about the distribution of the phenomenon among the target population. To understand the underlying reasons for the phenomenon, it is necessary to complement the questionnaire with some qualitative techniques, such as interviews

Use cases

City wide resident survey for Riga Territorial Plan until the year 2030  – Riga, Latvia, 2012-2013

The survey engaged ca. 8000 residents from all 58 neighbourhoods of Riga city. The aim of the survey was to collect the opinions about transportation, neighbourhood centres, neighbourhood identity, public amenities and urban environment. The opinions were summarised, identifying neighbourhood problems and possible development scenarios. The survey shaped the foundation for 11 thematic plans for Riga city. As a spin-off of the survey, 1752 active residents were identified and their contact data was collected. The contact data was used for other city projects for informing and engaging residents (RDPAD, 2017).

Try one of these tools & resources

  1. RDPAD (2017) 1. pielikums. Sabiedrības līdzdalība Rīgas teritorijas plānojuma līdz 2030. gadam izstrādē. Available at:
  2. Saunders M., Lewis P. & Thornhill A. (2016) Research Methods for Business Students. Seventh edition. Harlow, England: Pearson Education Limited.