Quantitative research questions:

What do I have to think about?

If your dissertation is attempting to answer one or more quantitative research questions, there are a number of factors you need to think about before getting started. These factors include: (a) the types of quantitative research questions you are trying to answer; (b) the variables you want to measure, manipulate and/or control; (c) how you should structure your research questions; and (d) whether you should use research questions as opposed to research hypotheses. Understanding these factors is important before reading some of the other articles on quantitative research questions on this website, which go into each factor in more detail.

This article addresses the following questions, which are an important starting point to understand what is required when creating quantitative research questions:

Each of these questions is addressed in more detail in the sections that follow. If you are interested in a particular section, click on the links below:

What type of quantitative research question are you trying to answer?

Dissertations that are based on a quantitative research design attempt to answer at least one quantitative research question. However, there is more than one type of quantitative research question that you can attempt to answer [see the article, Types of quantitative research question, for a more comprehensive look at these types of quantitative research question].

Quantitative research questions are based on one of three basic approaches to examining the variables you are interested in. These three basic approaches involve either describing, comparing or relating.

Let's imagine we are interested in examining Facebook usage amongst university students in the United States.

These three approaches to examining the variables you are interested in (i.e., describing, comparing and relating) are addressed by setting descriptive, comparative or relationship-based research questions. Understanding the difference between these three types of quantitative research question is important for a number of reasons. For example:

To learn more about these three types of quantitative research question (i.e., descriptive, comparative and relationship-based research questions) in more detail, see the article: Types of quantitative research question.

What variables are you trying to measure, manipulate and/or control?

Having established the quantitative research questions you want to answer, it is important to identify the variables that you intend to measure, manipulate and/or control. This is a critical component of experimental, quasi-experimental and relationship-based research designs [see the section on Quantitative research designs to learn more]:

In order to identify the variables that you intend to measure, manipulate and/or control, you also need to be able to recognise the different types of variables (i.e., independent and dependent; categorical or continuous variables) you intend to study. Whilst we describe these types of variables in detail in the article, Types of variables, you need to be aware of the differences between independent and dependent variables, and categorical and continuous variables.

At this stage, you should now know:

Armed with this knowledge, you now need to think about how to structure your quantitative research questions; that is, how you can write out your research questions in a way that the reader can clearly understand what you are trying to achieve.

How should you structure your quantitative research question?

There is no "one best way" to structure a quantitative research question. However, we recommend an approach that is based on three steps:

  1. Choose the type of quantitative research question you are trying to create

    The type of quantitative research question that you use in your dissertation (i.e., descriptive, comparative and/or relationship) needs to be reflected in the way that you write out the research question; that is, the word choice and phrasing that you use when constructing a research question tells the reader whether it is a descriptive, comparative or relationship-based research question. Therefore, in order to know how to structure your quantitative research question, you need to start by selecting the type of quantitative research question you are trying to create: descriptive, comparative and/or relationship.

  2. Set out the first words that start the research question

    Quantitative research questions tend to start with words like "What are", "How do", "Does", "How often", amongst others. Which words you start with will depend on the type of quantitative research question you are trying to create (i.e., descriptive, comparative and/or relationship) and the goal of the question.

  3. Determine the correct order for the variables you are investigating

    The type of quantitative research question you are trying to create (i.e., descriptive, comparative and/or relationship) and the choice of variables you are trying to measure, manipulate and/or control (i.e., independent, dependent and/or control variables) influence how you structure the research question. As a general rule, we suggest that independent variables are set out first, followed by dependent variables, and then control variables (if there are any).

In the section, How to structure quantitative research questions, we discuss these three steps in more detail, providing examples along the way.

Should you use quantitative research questions or research hypotheses?

Quantitative research questions and research hypotheses are designed to accomplish different tasks:

Sometimes dissertations should include both research questions and research hypotheses although this is not always the case:

If you choose to use research hypotheses, whether instead of research questions or in addition to them, these should be written differently to research questions. However, if you are using quantitative research questions, we have articles that can help you learn about the different types of quantitative research questions and how to structure quantitative research questions.