What are the four levels of measurement?

Levels of measurement tell you how precisely variables are recorded. There are 4 levels of measurement, which can be ranked from low to high:

Nominal: the data can only be categorised.
Ordinal: the data can be categorised and ranked.
Interval: the data can be categorised and ranked, and evenly spaced.
Ratio: the data can be categorised, ranked, evenly spaced and has a natural zero.

What Is Nominal Data? | Examples & Definition

What Is Ordinal Data? | Examples & Definition

What Is Interval Data? | Examples & Definition

What Is Ratio Data? | Examples & Definition

Levels of measurement: Nominal, ordinal, interval, ratio

Frequently asked questions: Statistics

How do I decide which level of measurement to use?: Some variables have fixed levels. For example, gender and ethnicity are always nominal level data because they cannot be ranked.

However, for other variables, you can choose the level of measurement. For example, income is a variable that can be recorded on an ordinal or a ratio scale:

At an ordinal level, you could create 5 income groupings and code the incomes that fall within them from 1–5.

At a ratio level, you would record exact numbers for income.

If you have a choice, the ratio level is always preferable because you can analyse data in more ways. The higher the level of measurement, the more precise your data is.
Why do levels of measurement matter?: The level at which you measure a variable determines how you can analyse your data.

Depending on the level of measurement, you can perform different descriptive statistics to get an overall summary of your data and inferential statistics to see if your results support or refute your hypothesis.
What is statistical analysis?: Statistical analysis is the main method for analyzing quantitative research data. It uses probabilities and models to test predictions about a population from sample data.
What symbols are used to represent null hypotheses?: The null hypothesis is often abbreviated as H₀. When the null hypothesis is written using mathematical symbols, it always includes an equality symbol (usually =, but sometimes ≥ or ≤).
What symbols are used to represent alternative hypotheses?: The alternative hypothesis is often abbreviated as H_a or H₁. When the alternative hypothesis is written using mathematical symbols, it always includes an inequality symbol (usually ≠, but sometimes < or >).
What happens to the shape of Student’s t distribution as the degrees of freedom increase?: As the degrees of freedom increase, Student’s t distribution becomes less leptokurtic, meaning that the probability of extreme values decreases. The distribution becomes more and more similar to a standard normal distribution.
What happens to the shape of the chi-square distribution as the degrees of freedom increase?: When there are only one or two degrees of freedom, the chi-square distribution is shaped like a backwards ‘J’. When there are three or more degrees of freedom, the distribution is shaped like a right-skewed hump. As the degrees of freedom increase, the hump becomes less right-skewed and the peak of the hump moves to the right. The distribution becomes more and more similar to a normal distribution.

Types of editing	Available at Scribbr?
Proofreading Correction of superficial mistakes, such as typos, misspellings, punctuation errors and consistency errors.	Yes! This is the “proofreading” in Scribbr’s standard service. It can only be selected in combination with editing.
Copy editing Focus on grammar, syntax, style, tone and the conventions of the field. The editor also considers the internal logic of the text and flags any obvious contradictions.	Yes! This is the “editing” in Scribbr’s standard service. It can only be selected in combination with proofreading.
Line editing Focus on language, style, concision and choices. The editor helps you strengthen your story, polish your sentences and ensure that your use of language drives home your ideas.	Yes! Select the Structure Check and Clarity Check to receive a comprehensive edit equivalent to a line edit.
Developmental editing (i.e. content editing, substantive editing) This is the first step of the editing process and applies to very early drafts. The editor helps you structure your ideas, decide what story to tell and find direction for your writing.	No. This kind of editing involves heavy rewriting and restructuring. Our editors cannot help with this.

Types of editing

Available at Scribbr?

Proofreading
Correction of superficial mistakes, such as typos, misspellings, punctuation errors and consistency errors.

Yes!
This is the “proofreading” in Scribbr’s standard service. It can only be selected in combination with editing.

Copy editing
Focus on grammar, syntax, style, tone and the conventions of the field. The editor also considers the internal logic of the text and flags any obvious contradictions.

Yes!
This is the “editing” in Scribbr’s standard service. It can only be selected in combination with proofreading.

Line editing
Focus on language, style, concision and choices. The editor helps you strengthen your story, polish your sentences and ensure that your use of language drives home your ideas.

Yes!
Select the Structure Check and Clarity Check to receive a comprehensive edit equivalent to a line edit.

Developmental editing (i.e. content editing, substantive editing)
This is the first step of the editing process and applies to very early drafts. The editor helps you structure your ideas, decide what story to tell and find direction for your writing.

No.
This kind of editing involves heavy rewriting and restructuring. Our editors cannot help with this.

Have a thesis expert improve your writing

Check your thesis for plagiarism in 10 minutes

Generate your APA citations for free!

Have a thesis expert improve your writing

Check your thesis for plagiarism in 10 minutes

Generate your APA citations for free!

What are the four levels of measurement?

Related posts

Frequently asked questions: Statistics

Questions?

Ask our team

Frequently asked questions

How does the sample edit work?