Ibn al-Haytham prioritized direct observation of natural phenomena as the starting point for scientific inquiry. His work was characterized by detailed and systematic observations, which formed the basis for his hypotheses and theories.

Ibn al-Haytham was a pioneer in using controlled experiments to test his theories. He designed and conducted experiments to investigate the behavior of light, vision, and other phenomena. His experimental approach was rigorous and systematic.

Ibn al-Haytham integrated mathematics into his scientific investigations, using mathematical principles to analyze experimental data, formulate theories, and make predictions. He believed that mathematics was essential for understanding the natural world.

Ibn al-Haytham emphasized the importance of skepticism and critical thinking in scientific inquiry. He was willing to challenge established theories and question assumptions, advocating for evidence-based reasoning.

Implicitly, Ibn al-Haytham's detailed descriptions of his experiments allowed others to replicate and verify his findings, which is a cornerstone of modern scientific methodology.