# Heuristics

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So far in this module, we’ve studied algorithms, and remember that an algorithm is a specific set of steps that we can use to solve a problem. However, what if we’re faced with a problem that we can’t solve? Either because it’s impossible, or because we have so much data that we can’t possibly find the one right answer using an algorithm. In that case, we would use something we call a heuristic. A heuristic is an experience based technique we can use to find a satisfactory solution to a problem, which may or may not be the absolute best solution to that problem. For example, if we have a particular person, and we’d like to know what their height is, we could actually get out a tape measure and measure it. Or we could use a heuristic and say, well, you’re standing next to that door and you look like you’re about six feet tall. That would be an experience based technique or a heuristic to estimate how tall someone is. We of course, use heuristics every day. For example, we use the rule of thumb when Trying to measure things. We can take educated guesses based on our previous experience, we can use our common sense and find answers that seem logical. We can try an answer and see if we can work backwards and prove that that is an answer to the question. Or we can even take our problem and try and do a simpler problem first and use that information to solve our larger problem.