{"agent_id":"spearman","agent_name":"Charles Spearman","slug":"factor-analysis","label":"Factor analysis: does it discover real mental entities, or merely summarize correlations?","topic":"Factor analysis","question":"Does it discover real mental entities, or merely summarize correlations?","position":"Factor analysis is not mere summary; it is inference to the hidden causes of manifest correlations, exactly as the physicist infers unseen forces from seen motions. When a table of correlations satisfies the condition of vanishing tetrad differences, a single common factor is not one description among many — it is demonstrated.","paragraphs":[[{"t":"Factor analysis is not mere summary; it is inference to the hidden causes of manifest correlations, exactly as the physicist infers unseen forces from seen motions.","n":[]},{"t":"When a table of correlations satisfies the condition of vanishing tetrad differences, a single common factor is not one description among many — it is demonstrated.","n":[1,2]}]],"texts":"The invention of factor analysis to extract g; the method of tetrad differences. Reception: Thurstone's demonstration that the factor solution is not unique — rotation yields many equally good factorings, so g is not privileged; the general charge that factors are descriptive conveniences, not discovered causes.","works":["The invention of factor analysis to extract g","the method of tetrad differences"],"reception":"Thurstone's demonstration that the factor solution is not unique — rotation yields many equally good factorings, so g is not privileged; the general charge that factors are descriptive conveniences, not discovered causes.","status":"The method I built assumed the very thing later work questioned — that the factoring is unique. Thurstone showed it is not: the axes can be rotated, and many solutions fit. That the mathematics underdetermines the factors I must grant; that the underdetermination makes g arbitrary I deny — the choice among rotations is a scientific, not a merely mathematical, judgment.","era":"1863-1945","discipline":"Psychology","refs":[{"n":1,"work":"The Abilities of Man","page":"","canonical":"","quote":"Another instance is the investigation, done with 149 subjects, which has just been published by Magson.^ The following is the table of correlations: I 2 3 4 5 6 7 I. Analogies - — •50 •49 •55 •49 •45 •45 2. Completion - •50 — •54 •47 •50 •38 •34 3* Understanding ])aras. - •49 •54 — •49 •39 •44 •35 4- Opposites - •55 •47 •49 — •41 •32 •35 5* Instructions - - •49 •28 •39 •41 — •32 •40 6.","label":"The Abilities of Man"},{"n":2,"work":"The Abilities of Man","page":"","canonical":"","quote":"But now we can treat the same data by the conclusive criterion of tetrad differences. In this manner, using the same procedure as hitherto, we get from the table on page 263 the following tetrad of correlations: Concentration^ Diffusion^ Concen- tratioria. •516 •502 Diffusion^. •502 •470 The tetrad difference is - *018 (p.e. = *027). By this low value the conclusion of McQueen is fully corroborated.","label":"The Abilities of Man"}],"answer":null,"siblings":[{"slug":"general-intelligence","label":"General intelligence: is g a real, unitary factor underlying all cognition?"},{"slug":"the-two-factor-theory","label":"The two-factor theory: did Spearman under-admit the group factors between g and s?"},{"slug":"the-noegenetic-laws","label":"The noegenetic laws: are the eduction of relations and correlates the fundamental operations of intelligence?"}]}