A hypothesis is a proposed idea or explanation that can be tested. In simple terms, it is an educated guess, but one based on observation, existing knowledge, or a question you want to investigate.
In science and research, a hypothesis is more specific than a casual guess. It predicts what you expect to happen, and it should be written in a way that can be checked through observation, an experiment, or data analysis.
What it means
A hypothesis usually starts with a question. For example, if someone asks whether more sunlight helps plants grow faster, a hypothesis might be: "Plants that get more sunlight will grow taller than plants that get less sunlight." That statement can be tested, which makes it useful in research.
A good hypothesis is clear, specific, and testable. It should point to a relationship between things you can measure, such as cause and effect, or comparison between groups.
How it differs from a theory
A hypothesis is not the same as a theory. A hypothesis comes first, before testing. A theory is broader and is usually built after lots of evidence has been collected over time.
So a hypothesis is the starting point for investigation, while a theory is a more established explanation. In other words, a hypothesis asks, "What do I think will happen?", and then research checks whether that idea holds up.
Simple examples
- "If plants receive more water, they will grow faster."
- "Students who study longer will score higher on a quiz."
- "Sleeping less than seven hours will reduce concentration."
Each of these can be tested, measured, and possibly proven wrong, which is exactly why they count as hypotheses.
In everyday use
Outside science, people sometimes use "hypothesis" to mean a smart guess or a possible explanation. In formal writing, though, it usually means a testable statement meant to guide research.
In short, a hypothesis is a careful, testable idea about what might be true. It helps turn curiosity into something you can actually investigate.