Last edited 06 Oct 2021

Quantitative v qualitative

The word ‘quantitative’ refers to objective measures of definable factual characteristics such as numbers and statistics that are capable of being analysed – that is, 'quantities'. Quantities are properties that can exist as a multitude or magnitude and can be given a numerical value or compared in terms of more, less or equal.

Quantitative research can be used deductively to test a theory that can be presented in one of two ways:

A hypothetical statement such as ‘if x then y’.
An educated ‘guess’.

The word ‘qualitative’ refers to more subjective descriptions, views and opinions - that is 'qualities'. Qualitative properties are typically observed and cannot be assigned a numerical value.

Qualitative research generally uses a smaller sample size than quantitative research, but the information obtained can be more personal and in-depth.

Broadly, the two categories of qualitative research are exploratory and attitudinal:

Exploratory research is used primarily to gain a greater understanding of a particular subject. It is useful for diagnosing a situation, considering alternative ideas and discovering new ones that haven’t been previously considered. The most common method of exploratory research is interviewing, where the raw data will be the transcribed answers. Another common method is a questionnaire (usually with open-ended questions).
Attitudinal research is used to evaluate the opinions or views of individuals in a way that is subjective. Examples are questions that ask the individual to express their level of agreement with a statement, or to rank preferences.

NB Guide for Effective Benefits Management in Major Projects, published by the Infrastructure and Projects Authority in October 2017, defines qualitative as: ‘Whereby something is better measured through its quality rather than a quantitative measure. Something which is subjective or difficult to verify but is useful in understanding experiences and attitudes.’