I don't understand...
Here are just three from the previously cited Wiki article.
I would suggest you read the article to gather more data.
Robert Grosseteste (/ˈɡroʊstɛst/ grohs-test) or Grossetete (/ˈɡroʊsteɪt/ grohs-tayt;[2] c. 1175 9 October 1253) was an English statesman, scholastic philosopher, theologian, scientist and Bishop of Lincoln. He was born of humble parents at Stradbroke in Suffolk. A.C. Crombie calls him "the real founder of the tradition of scientific thought in medieval Oxford, and in some ways, of the modern English intellectual tradition".
Pūr Sinɑʼ (Persian ابن سینا or ابو علی* سینا or پور سينا Pur-e Sina; [ˈpuːr ˈsiːnɑː] "son of Sina"; August c. 980 June 1037), commonly known as Ibn Sīnā, or in Arabic writing Abū ʿAlī al-Ḥusayn ibn ʿAbd Allāh ibn Al-Hasan ibn Ali ibn Sīnā[2] (Arabic أبو علي الحسين بن عبد الله بن سينا
or by his Latinized name Avicenna, was a Persian[3][4][5][6] polymath, who wrote almost 450 works on a wide range of subjects, of which around 240 have survived. In particular, 150 of his surviving works concentrate on philosophy and 40 of them concentrate on medicine.[7]
His most famous works are The Book of Healing, a vast philosophical and scientific encyclopedia, and The Canon of Medicine,[8] which was a standard medical text at many medieval universities.[9] The Canon of Medicine was used as a textbook in the universities of Montpellier and Leuven as late as 1650.[10] Ibn Sīnā's Canon of Medicine provides an overview of all aspects of medicine according to the principles of Galen (and Hippocrates).[11][12]
His corpus also includes writing on philosophy, astronomy, alchemy, geology, psychology, Islamic theology, logic, mathematics, physics, as well as poetry.[13] He is regarded as the most famous and influential polymath of the Islamic Golden Age.[14]
Roger Bacon[edit]
Roger Bacon was inspired by the writings of Grosseteste. In his account of a method, Bacon described a repeating cycle of observation, hypothesis, experimentation, and the need for independent verification. He recorded the way he had conducted his experiments in precise detail, perhaps with the idea that others could reproduce and independently test his results.
About 1256 he joined the Franciscan Order and became subject to the Franciscan statute forbidding Friars from publishing books or pamphlets without specific approval. After the accession of Pope Clement IV in 1265, the Pope granted Bacon a special commission to write to him on scientific matters. In eighteen months he completed three large treatises, the Opus Majus, Opus Minus, and Opus Tertium which he sent to the Pope.[35] William Whewell has called Opus Majus at once the Encyclopaedia and Organon of the 13th century.[36]
Part I (pp. 122) treats of the four causes of error: authority, custom, the opinion of the unskilled many, and the concealment of real ignorance by a pretense of knowledge.
Part VI (pp. 445477) treats of experimental science, domina omnium scientiarum. There are two methods of knowledge: the one by argument, the other by experience. Mere argument is never sufficient; it may decide a question, but gives no satisfaction or certainty to the mind, which can only be convinced by immediate inspection or intuition, which is what experience gives.
Experimental science, which in the Opus Tertium (p. 46) is distinguished from the speculative sciences and the operative arts, is said to have three great prerogatives over all sciences:
It verifies their conclusions by direct experiment;
It discovers truths which they could never reach;
It investigates the secrets of nature, and opens to us a knowledge of past and future.
Roger Bacon illustrated his method by an investigation into the nature and cause of the rainbow, as a specimen of inductive research.[37]