05. Types of Data

In order to demonstrate a cause and effect relationship between and IV and a DV we must first learn about the nature of the data we are working with.

Primary data is collected directly by the researcher for their specific purpose and has not been collected before. If you conduct an experiment in your classroom you are collecting primary data

Secondary data is not collected by the researcher and is likely to have already been used in some research before. An example of this is if you were to collect some data from the Australian Bureau of Statistics.

Quantitative data is information that is expressed numerically. As suggested by the term, it is information about the ‘quantity’ or amount of what is being studied; that is, how much or how many of something there is.

This type of data is usually expressed in the form of units of measurement or numbers, such as raw scores, percentages, means, standard deviations and so on. For example, the height or age of a participant is considered quantitative data as both of these characteristics can be expressed in units of measurement (centimetres or years). Similarly, the percentages of participants who respond with ‘Agree’ or ‘Disagree’ to interview questions, or the mean time taken to solve a problem in an experiment, are quantitative data.

Quantitative data may also take the form of a direct reading of brainwave activity, Heart Rate, Respiratory Rate etc.

Quantitative data is preferable to other types of data as it allows us to organise, arrange and evaluate the data in a statistical manner. We can look at the mean, the mode, the standard deviation as well as some more detailed means of data assessment such as T-Tests or Chi Square tests.

Sometimes it is not possible to collect numeric data though.

Qualitative data is information that is not expressed numerically. As suggested by the term, it is information about the ‘qualities’ or characteristics of what is being studied.

It may be in the form of descriptions, words, meanings, photos, pictures, audio or video recordings, and so on. It can describe any aspect of a person’s mental experience or behaviour; more specifically, what something is like, how something is experienced or whether it was an X or Y type of experience.

Both qualitative and quantitative data can fall under the objective or subjective categories sepending on how it was collected

Objective data is information that is observable, measurable, verifiable and free from the personal bias of the researcher. For example, the data can be seen, heard or touched (observable), counted or precisely described (measurable), can be confirmed by another researcher (verifiable) and is factual (free from personal bias). In science, there is a strong preference for objective data.

Data collected through a strictly controlled experiment in which observations and measurements are planned, precise and systematic is considered objective. So is data collected using an assessment device that yields a score, such as an intelligence or personality test.

Subjective data is information that is based on personal opinion, interpretation, point of view or judgment. Unlike objective data, this data is determined by the research participants and often cannot always be verified by the researcher. It is often biased, can vary from person to person, day to day from the same person, and is not always entirely accurate.

When using subjective data, researchers assume that participants are honest, can accurately recall what they are asked to describe and are able to give detailed accounts about their thoughts, feelings or behaviour.

While objective data is usually Quantitative, its not always the case, for example, if I asked you to rate the quality of your sleep on a scale of 1 to 10, its still quantitative, but also subjective as there is no finite rating system for sleep that we all use.

Objective, quantitative data can be preferable in order to begin a statistical analysis of the relationship between an IV and a DV, but often Subjective and qualitative data can provide us with a greater insight into the specifics of what is being observed.