Structured vs Unstructured Questions: When to Use Each in Surveys

Data is the new gold. Companies are using it to understand how customers feel about their products, figure out what they want, and even predict future trends. One of the best ways to collect data is through surveys - standardised sets of survey questions used to gather information from a sample population.

When creating a survey, it is useful to know that there are two main types of questions you can ask: structured and unstructured. The type of question impacts the type of data you'll get back. So it's important to understand the difference, and when to use each one.

This post will teach you all about structured and unstructured survey questions - from definitions and examples to the advantages and best use cases of each. You'll also learn how to combine question types to get even more insightful data. Let's start by defining what structured and unstructured survey questions are.

What are structured questions?

Structured questions are sometimes called closed-ended questions. They provide a limited, pre-defined set of response options for respondents to choose from. Some common examples include:

• Multiple-choice: These give a list of options to pick from. For example, "What's your favourite ice cream flavour? A) Chocolate, B) Vanilla, C) Strawberry, D) Other". The multiple choice question allows respondents to choose from one or more of these answers, depending on what you decide.
• Likert scale: This type of question asks respondents how much they agree or disagree with something. It usually goes from "Strongly Disagree" to "Strongly Agree". For example, "I enjoy reading books: Strongly Disagree / Disagree / Neutral / Agree / Strongly Agree."
• Dichotomous: These are yes or no questions. Simple and straight to the point! For instance, "Do you own a car? Yes / No"
• Single-choice: In this case, there is only one correct answer for the respondent. When asked, "Where were you born?" they will have to reply with one specific country or city (i.e., Bristol)

As you can see, structured questions lead to standardised responses that are easy to categorise and analyse. However, they limit the respondent's ability to elaborate or explain their answers.

Advantages of using structured questions

There's no denying that a structured survey has its limits. Namely, it is more difficult for respondents to explain their answers in detail. But they do have some big plus points:

Easy to analyse

Surveys aim to gather insights into people's opinions. But human sentiment is complex, with many shades of meaning. Structured questions remove this ambiguity by providing clear, defined response options that generate data you can quickly compare and contrast.

For example, if you ask "Did you enjoy our product?" with a yes/no answer, it's easy to see how many customers liked it. You don't have to guess what they meant.

Standardisation of responses

When you're looking at survey results, you need to compare answers to glean insights. If everyone says something completely unique, it's more challenging to spot patterns. Structured questions solve this problem. They make sure everyone answers in the same format.

Let's say you want to know how respondents feel about a new phone. With structured questions, you might find that 80% rate it 4 or 5 out of 5 stars. That's a clear sign that they like it! But if everyone goes on a tangent about which features are present or missing, you might not necessarily get the info you're looking for.

Efficient for large-scale surveys

Unstructured answers are usually longer and more detailed. That's great, but it takes time to write and analyse them. Analysing 100 long answers might be doable. But what about 10,000 or 100,000? That's a lot of reading!

Structured questions save time and resources. They're perfect for big surveys such as larger enterprise projects or citizen engagement feedback, because the answers are quick to process. There are even tools to help, like those at SmartSurvey.

Higher completion rate

Even your most loyal customers are busy individuals. They might want nothing more than to help you refine your offering, but their time remains precious, and long surveys can be off-putting. A structured survey is short and snappy. This means more people are likely to finish it.

What are unstructured questions?

Unstructured questions are the opposite of what we just defined. They are open-ended, allowing respondents to answer however they want in free-form writing. Common examples include:

• Open-ended questions: These let respondents write whatever they want. Like "What do you think about our new product?"
• Probing questions: These often come after a structured question to get more info. For example, "Why did you choose that rating?"
• Hypothetical questions: Ask what would you do in a made-up situation. Such as "If you were in charge for a day, what would you change?"
• Essay-style responses: These are for longer, more detailed answers. Like "Describe your ideal vacation and why you'd enjoy it."

Unstructured questions lead to qualitative, detailed responses with more context. But they make standardising and analysis more difficult.

Advantages of using unstructured questions

These answers can be long - from a few words to several paragraphs, making them harder to analyse than structured responses. So why bother with them? They can offer some significant advantages:

Rich, qualitative insights

At the end of the day, we're after data. Unstructured questions give you rich, detailed info. You'll understand what people really think and feel.

For example, asking, "How was your experience with our customer service?" might reveal issues you never knew existed. Maybe lots of people mention how friendly the staff are, but wish responses were quicker. With a simple scale rating, it would be impossible to uncover that insight.

Flexibility in responses

Structured questions can be limiting. If the answer someone wants to give isn't an option, they might feel stuck. Even worse, they might pick an answer that doesn't really match what they think.

Unstructured questions let respondents express themselves freely using their own words, leading to more nuanced, meaningful answers.

Discover new ideas

With structured questions, you have to think of all the possible answers in advance. But what if there's something you didn't consider? Unstructured questions can lead to new discoveries. Respondents might bring up ideas or issues you never thought of. This can spark new discussions or research areas for your business.

Comparing structured and unstructured questions

So, we've looked at both types of questions. But how do they stack up against each other?

The main difference is in how people answer and what kind of data you get. Structured questions give you neat, easy-to-analyse numbers. Unstructured questions give you detailed, varied responses. So, quantitative vs qualitative research in other words.

Think of it like a school test. Structured questions are like multiple-choice - quick to answer and easy to mark. Unstructured questions are like essay questions - they take longer but give a deeper understanding.

Both have their strengths and weaknesses. Knowing these helps you decide when to use each type. Let's look at that next.

When to use structured questions

Structured questions excel at:

• Quantitative research: If you want numerical data to quantify outcomes, metrics, or opinions - use structured questions. For example, customer satisfaction rating scales.
• Standardised data collection: If you need to easily compare/contrast responses across a population, use consistent structured questions. For example, brand awareness metrics.
• Large respondent samples: Structured questions make it feasible to gather and process data from thousands of respondents.

Structured questions are popular in many fields. Market research often uses them to get quick feedback on products. Political polls use them to gauge public opinion quickly. Customer satisfaction surveys often use rating scales to measure how happy clients are with a service.

When to use unstructured questions

Structured questions might be more common, but unstructured ones shine in certain situations. They're great when you need:

• Exploratory research: If you're still developing a concept and want detailed, contextual insights on user perspectives, use open-ended questions. This is common in product development research.
• Capturing detailed personal experiences: Let respondents tell their full story by using unstructured questions when you want rich, qualitative details on a personal experience. For example, customer service feedback.
• Small to medium-sized respondent samples: When you have time to read and analyse detailed responses.

Unstructured questions are often used in fields like psychology and sociology. They're great for understanding complex human experiences. Product development teams might use them to get detailed feedback on new ideas. Journalists often use open-ended questions to get the full story in interviews.

Combining structured and unstructured questions

Rather than choosing one or the other, many surveys combine structured and unstructured questions to get the best of both worlds.

Using both types gives you the best of both worlds. You get easy-to-analyse data from structured questions and detailed insights from unstructured ones. But be careful! Too many questions, especially open-ended ones, can make your survey too long.

Here are some tips for using both types:

1. Start with structured questions to get basic info
2. Use unstructured questions to dig deeper into interesting topics
3. Keep your survey balanced - don't overload it with too many open-ended questions
4. Put the most important questions first in case people don't finish the survey
5. Only add open-ended questions when additional detail is truly needed

Potential challenges and considerations

While powerful, unstructured survey questions also pose some challenges:

• Respondent fatigue: Too many open-ended questions lead to survey drop-off. Keep them short and focused.
• Depth vs. analysis: More detail increases insights but makes large-scale analysis less feasible over thousands of free-form responses.
• Survey platform capabilities: Ensure your survey software has features to easily collect, organise and analyse unstructured data. SmartSurvey is ideal for both structured and unstructured questions.
• Ethical concerns: Take steps to protect privacy, as open-ended responses can reveal sensitive information.

Wrapping up

By using the right mix of structured and unstructured questions, you can get the best possible information. Each format serves a purpose in quantifying metrics and capturing personal insights.

Thoughtfully combining closed and open-ended questions will lead to rich, actionable data to drive business success.

Key takeaways

Understanding question types: Surveys primarily use two types of questions: structured (closed-ended) and unstructured (open-ended). Structured questions offer predefined response options, making data easy to categorise and analyse, while unstructured questions allow for free-form responses, providing richer, more detailed insights.

Benefits of structured questions: Structured questions are efficient for large-scale surveys, offer higher completion rates, and make it easier to standardise and analyse responses. They are ideal for quantitative research, standardising data collection, and gathering data from large respondent samples.

Benefits of unstructured questions: Unstructured questions excel in capturing detailed, qualitative insights and offer flexibility for respondents to express their thoughts freely. They are particularly useful in exploratory research, understanding personal experiences, and discovering new ideas that structured questions might miss.

When to use structured questions: Structured questions are best used when seeking numerical data, conducting quantitative research, or when you need standardised responses across large populations. They are commonly employed in market research, political polling, and customer satisfaction surveys.

When to use unstructured questions: Unstructured questions are ideal for exploratory research, capturing detailed personal experiences, and when working with small to medium-sized samples. These questions are often used in fields like psychology, sociology, and product development to gather in-depth feedback.

Combining both question types: Many surveys benefit from a combination of structured and unstructured questions. This approach allows for the collection of easy-to-analyse data alongside more nuanced insights. However, it's important to balance the survey design to avoid respondent fatigue, especially with open-ended questions, and ensure that the survey platform can handle both question types effectively.

(See also: our collection of sample survey questions for common use cases)