Year 12 ยท Student investigation
Does a neat decomposition preserve the behaviour we care about?
Keep an individual record even when you investigate in pairs. Record the exact settings, source and data split.
Will keeping all 10 components with zero edit reproduce the original model? Could a small matrix error hide a large group error?
What did you change? What stayed the same? What did you notice?
Check exact reconstruction at rank 10 and edit 0. Compare ranks 1, 5 and 10, then edit the leading component. Inspect Kiki and other-query denominators before changing the assumed population share.
A paired model-edit report with rank, edit, group loss, exact answers and population assumptions.
This activity can show _ . It cannot tell us _ . A new case I would test is ____ .
Use fictional data. Download or print your work before leaving.