Declarative knowledge

Declarative knowledge is the kind of knowledge that includes facts and information you can explain using words. If you know that Paris is the capital of France or that water boils at 100 degrees Celsius, you are using declarative knowledge.^[1] It is called "declarative" because you can declare or state it out loud. This type of knowledge is different from knowing how to do something, like riding a bike or tying your shoes, that kind is called procedural knowledge.^[2] In school, much of what students are taught, like dates in history, math rules, or science facts, is declarative knowledge.^[3] There are two main types of declarative knowledge: semantic memory and episodic memory. Semantic memory includes general facts about the world, such as knowing that cats are animals or that 2 + 2 equals 4. Episodic memory, on the other hand, is about personal experiences, like remembering what happened on your first day of school or what you had for lunch yesterday. Both types can be described with words, but one is more about facts and the other is about events in your life.^[4]

Declarative knowledge can be expressed using declarative sentences stored in books.

Declarative knowledge is stored in specific parts of the brain, especially in an area called the hippocampus.^[5] Scientists know this because of famous medical cases, like a man known as patient H.M., who lost his ability to make new memories after part of his brain was removed. He could still do tasks like drawing or riding a bike, but he could not remember facts he had just learned. This shows that the brain stores declarative and procedural knowledge in different ways.^[6] When you study to remember facts, it helps to use techniques like making connections to things you already know, creating pictures in your mind, or practicing by testing yourself.^[7] These strategies are better than just repeating something over and over, which does not usually help you remember for long.^[8] In school tests, multiple-choice and short-answer questions often check your declarative knowledge because they ask you to recall facts.^[9]

In computers and artificial intelligence, declarative knowledge is also important. Programmers use special languages to put facts into machines so they can “know” things, like what animals live in the ocean or what causes a fever.^[10] These systems can then figure out new information using logic, kind of like solving puzzles with the facts they already have. Subjects like math and philosophy rely a lot on declarative knowledge because they involve understanding and working with ideas and statements.^[11] But even though knowing facts is important, focusing only on memorizing can sometimes make it hard to see the bigger picture. That is why teachers today often use learning methods that mix memorizing facts with using them in creative or thoughtful ways, such as solving problems or explaining ideas.^[12]

When you have a lot of declarative knowledge stored in your brain in an organized way, it helps you think faster and more clearly. This is especially true in difficult tasks. For example, doctors use their medical knowledge to understand symptoms quickly, and chess players spot familiar patterns that help them plan their next move.^[13] Sometimes, people know things without realizing it. For example, you may speak correctly using grammar rules without being able to explain them. These are examples where knowledge is partly declarative but not fully conscious until someone teaches it to you.^[14]