How to know better if it will rain

We have made big computers that tell us if it will rain, or be hot, or be windy in the next days. To know what will happen in the future we need lots of information about what the air is like now. This information comes from many machines, like cameras flying around the world in space, that can tell us many different things. Some machines can tell us how hot the air is, others how wet, and others how fast the wind is. But the problem is, that not all information the machines give us help the same. Sometimes adding some kinds of information about the air now even makes the computer tell us the wrong things about the future. Finding out how much different kinds of information help is not easy, so people have had many ideas to guess how much which machines help. In this talk I will look at some different ideas people had on how to guess which information helps. I use a very simple computer and many strange numbers to show that other people did things wrong. But the good news is that we managed to fix their broken ideas, and now they work well.