Inter-rater reliability was

You usually follow this phrase with a statistical value or a descriptive word. For example, you might say it was high or was calculated using Cohen’s Kappa. It acts as the subject of your sentence. You are introducing a quality check for your work. Think of it as showing your receipts. You are telling your audience, "Hey, don't just take my word for it!"

Use this in any situation where people are grading or judging. It is most common in university papers or lab reports. You might use it when discussing a job interview process where three managers scored one candidate. It is perfect for professional presentations. Use it when you want to sound objective and thorough. It turns a subjective guess into a scientific fact.

Do not use this at a casual dinner party. If you tell your spouse, "Our inter-rater reliability on this pizza is low," they might roll their eyes. It is too heavy for simple personal opinions. Avoid it if only one person did the judging. You need at least two 'raters' for the phrase to make sense. Don't use it for things that are purely factual, like the height of a building.

This phrase comes from the world of psychometrics and social sciences. In Western academia, there is a huge emphasis on 'objectivity.' We worry that individual bias ruins results. This phrase became a 'gold standard' in the mid-20th century. It reflects a culture that values data over gut feelings. It is the language of the skeptical, evidence-based mind.

You might hear inter-observer agreement or inter-coder reliability. If you are looking at just one person over time, it becomes intra-rater reliability. In casual office talk, people might just say, "Are we on the same page?" But in a report, always stick to the formal version. It makes your findings look much more professional and trustworthy.