--- title: "What is Type-1 Error?" url: https://fibr.ai/glossary/type-1-error description: "A Type-1 error occurs when you falsely conclude a change had an impact, leading to incorrect decisions that can harm trust and sales in the long term." last_updated: 2026-05-05T11:57:06.951154+00:00 --- A Type-1 error happens when you wrongly conclude that a change made an impact when it didn’t. In testing, this means rejecting a true null hypothesis (false positive). Example: thinking a new button increased sales when, in reality, it was just random chance. This error often occurs when tests are run without enough data or statistical rigor. Reducing this error requires careful test design, larger sample sizes, and sticking to planned test durations. Businesses must watch out, as false positives lead to rolling out changes that don’t truly help. For instance, launching a new checkout flow based on misleading results may lower trust or sales in the long term. ### Explore more Glossary terms ##### Type-2 error A Type-2 error occurs when you fail to detect a real effect or improvement. In other words, you accept the null hypothesis when it’s false (false negative). Example: missing the fact that a new layout actually improves sign-ups. This often leads to lost opportunities because useful changes go unnoticed. Read More ##### Type-1 Error A Type-1 error happens when you wrongly conclude that a change made an impact when it didn’t. In testing, this means rejecting a true null hypothesis (false positive). Example: thinking a new button increased sales when, in reality, it was just random chance. Read More ##### Trust Badges Trust badges are small icons or symbols displayed on websites to build credibility and reassure users about safety, authenticity, or quality. Examples include SSL certificates, payment security icons, and more. They reduce hesitation during checkout by showing that the site is safe and reliable. The right trust badge placed at the right time can improve conversions. Read More ##### Title Tag A title tag is an HTML element that defines the clickable headline shown in search engine results and browser tabs. It describes the page content in about 50–60 characters. Title tags play a key role in SEO because they help search engines understand the topic and attract users to click. A good title tag is clear, descriptive, and includes the main keyword naturally. Read More ##### Testing in Production Testing in production means running experiments or deploying features directly on the live environment where real users interact. Instead of using a staging setup, teams test in the actual system to see how features behave under real-world conditions. While it provides accurate insights, it also carries risks like bugs or downtime affecting customers. Read More ##### Test Hypothesis A test hypothesis is a clear statement predicting what you expect to happen in an experiment. In CRO or usability testing, it outlines the change being tested, the expected impact, and the reason behind it. A good hypothesis is measurable, specific, and based on user research or past data, not just guesswork. Read More Delaware, USA Subscribe to our newsletter for exclusive updates and insights.