Map the directions around a small magnet

Place the magnet on one square and mark its orientation without moving it. Take a compass reading far away first to establish the background direction in the room.

Mark a magnet position and put compass readings at points on two sides of it. A useful prediction can say which direction an effect should move without specifying its exact size. Put that prediction next to the expected observation time or distance. If the pattern appears in the other direction, note how you would test whether it arose from a measurement condition or from your original explanation.

The needle can point in noticeably different directions at equally distant positions. Put the observations into order and keep the raw measurements or drawings. A result can be useful at more than one level. The direction of a change may be unmistakable while the exact size is uncertain. Describe the strongest pattern the records support and qualify measurements that depend on a faint boundary or a moving object.

Keep phones and metal tools away during the comparison. Wait for the needle to settle and note its direction at each selected position.

A metal desk fitting can alter the background reading before the magnet is added. Sketch your apparatus before you start and use the sketch to identify where each observation will be made. Write down the starting state before changing it. If another person repeats the trial, knowing the relative positions can matter more than the brand or appearance of the materials.

Make a baseline on the same grid without the magnet in place. End with a short account linking the changed condition, the observation, and its likely explanation. Include one uncertainty that would matter if you repeated it. This separates the physical idea explored by the demonstration from limits created by a household setup and gives another person a way to test the same claim.

Compare pairs of arrows after turning the magnet through half a turn. Use the empty setup once before introducing the change you want to study. A baseline can show motion from a loose support, light falling on the screen from another direction or variation in the way the sample starts. Record what you see at that stage as part of the experiment.

Write a row for each run and keep apparently odd results in the record. Mark things that went wrong, such as a shifted surface, uneven starting point or missed time, before judging the pattern. Changing how you record the behaviour halfway through can make two otherwise similar trials difficult to compare. Explain the outcome in a sentence that a reader can check against the figures or sketch. Use a second sentence for a proposed cause. If you can imagine a different cause that fits the same observations, describe a small test that would help distinguish the two. Comparing those predictions can make a follow-up clearer than simply repeating the same demonstration. Keep the compass several grid spaces from the magnet for the first reading. A strong effect at the starting point makes the background hard to establish. Write the independent change at the start of each row and keep the outcome beside it. Include anything about a failed run that would matter to somebody repeating the setup. If you later make a neat graph, keep the rough record as well so it remains possible to inspect the reasons for leaving out a point.

Rotate the magnet and survey several of the same points again to see which arrows respond most strongly. Observe the setup from the same place in each trial. A view from farther away can hide a shallow curve or make two positions look aligned. A short guide mark shows the place you used. Keep the recording method fixed as well when changing the setup itself is the point of the comparison.