Three guesses

About this video

Zara's notebook shows that her bean plant leans a little more towards the window every day. Now it is time for ideas about why. Maybe it grows towards the light coming through the window. Maybe towards the warmth of the radiator under the window. Or maybe towards the fresh air coming in at the gap under the frame. Each is a possible answer, and none is known to be true yet.

What makes them good starting points is that each one could be checked: Zara could move the light, switch off the radiator or close the gap, and the world could show the idea to be right or wrong. A possible answer to a question about the world that the world could show to be right or wrong is called a hypothesis. "The plant leans because it is sad" isn't one: nothing Zara could look at would ever tell her.

A hypothesis isn't a wild guess, since it comes from what was observed, and it isn't an answer either. It is where the finding out starts. Most hypotheses turn out to be wrong, and that is fine: one checked and thrown away still teaches you something, because one possible answer is gone. This video goes with the A Guess You Can Test lesson of Science Level 1 on Knaph.

Transcript

1. 0:00Zara's bean plant leans towards the window. Why?
2. 0:05Maybe the light. Maybe the warm radiator. Maybe fresh air from the gap.
3. 0:11Each one could be checked. Move the light, switch off the heat, close the gap.
4. 0:17But it leans because it is sad? Nothing could ever show that.
5. 0:23Most guesses turn out wrong. Each one ruled out still teaches you something.
6. 0:29A hypothesis is a guess about the world that you could check.