Consider, for example, how a physician makes his diagnosis--his inductive interpretation. If he is scientifically trained, he suspends--postpones--reaching a conclusion in order that he may not be led by superficial occurrences into a snap judgment. Certain conspicuous phenomena may forcibly suggest typhoid, but he avoids a conclusion, or even any strong preference for this or that conclusion until he has greatly (_i_) _enlarged_ the scope of his data, and (_ii_) rendered them more _minute_. He not only questions the patient as to his feelings and as to his acts prior to the disease, but by various manipulations with his hands (and with instruments made for the purpose) brings to light a large number of facts of which the patient is quite unaware. The state of temperature, respiration, and heart-action is accurately noted, and their fluctuations from time to time are exactly recorded. Until this examination has worked _out_ toward a wider collection and _in_ toward a minuter scrutiny of details, inference is deferred. [Sidenote: Summary: definition of scientific induction] Scientific induction means, in short, _all the processes by which the observing and amassing of data are regulated with a view to facilitating the formation of explanatory conceptions and theories_. These devices are all directed toward selecting the precise facts to which weight and significance shall attach in forming suggestions or ideas. Specifically, this selective determination involves devices of (1) elimination by analysis of what is likely to be misleading and irrelevant, (2) emphasis of the important by collection and comparison of cases, (3) deliberate construction of data by experimental variation. [Sidenote: Elimination of irrelevant meanings]