2026-06-01T03:13:27Zhttp://your-public-oai-url.example.comoai:archivesspace:/repositories/2/archival_objects/11712021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/1http://127.0.0.1:8081/repositories/2/archival_objects/1171Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)1 (37), Thomson to Ledermann, 2 Feb 19372 Feb 19371 letter (1 leaf, 2 sides)engEnglishThomson acknowledges receipt of Ledermann's letter and manuscript, expressing pleasure at Ledermann's continuing interest in factor analysis.
Thomson draws parallels between a formula Ledermann uses and the work of Kelley, specifically his pentad criterion as discussed in Crossroads in the Mind of Man.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11722021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/2http://127.0.0.1:8081/repositories/2/archival_objects/1172Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)2 (37), Thomson to Ledermann, 10 Feb 193710 Feb 19371 letter (1 leaf, 1 side)engEnglishThomson acknowledges receipt of Kelley's book, Crossroads in the Minds of Man. He advises Ledermann with regards to referencing Kelley's pentad criterion in his paper, while still recognising Ledermann's shorter method for arriving at the same result.
Thomson cites Psychometrika as the best publication for the paper, and offers to send it there if Ledermann is in agreement.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11732021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/3http://127.0.0.1:8081/repositories/2/archival_objects/1173Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)3 (37), Thomson to Ledermann, 16 Feb 193716 Feb 19371 letter (1 leaf, 1 side)engEnglishThomson informs Ledermann that his secretary, Miss Matthews, is typing three copies of Ledermann's paper in order to submit to Psychometrika, and that these will be sent to him should he wish to make any changes before admission.
Thomson advises that he need not simplify the paper.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11742021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/4http://127.0.0.1:8081/repositories/2/archival_objects/1174Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)5 (37), Thomson to Ledermann, 5 Jun 19375 Jun 19371 letter (1 leaf, 2 sides)engEnglishThomson informs Ledermann that his leave of absence has been granted for 1937-1938, and tells him that he will be speaking with A C Aitken regarding the possibility of adding a mathematical computer to his team.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11752021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/5http://127.0.0.1:8081/repositories/2/archival_objects/1175Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)7 (37), Thomson to Ledermann, 28 Jun 193728 Jun 19371 letter (2 leafs, 3 sides)engEnglishThomson discusses his plans for summer, which include lecturing at the Bingley Training College, and staying at Glenapp, Ayrshire, and informs Ledermann that he is not sure where he will be based for winter.
He advises Ledermann to undertake preparatory reading, and attaches a short reading list which includes the work of T L Kelley, L L Thurstone, W P Alexander, and Cyril Burt.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11762021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/6http://127.0.0.1:8081/repositories/2/archival_objects/1176Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)8 (37), Thomson to Ledermann, 8 Jul 19378 Jul 19371 letter (1 leaf, 2 sides)engEnglishThomson asks Ledermann to meet him at the Thackeray Hotel in London. He suggests further publications for Ledermann to read, particularly in relation to matrix methods, including publications by G Udny Yule, R A Fisher, and T L Kelley.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11772021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/7http://127.0.0.1:8081/repositories/2/archival_objects/1177Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)9 (37), Thomson to Ledermann, 17 Jul 193717 Jul 19371 letter (6 leafs, 6 sides)engEnglishThomson discusses the difficulties of calculating correlations between persons, referring to Burt's article, Correlations Between Persons, from the British Journal of Psychology, Jul 1937; his own paper, On Complete Families, from the British Journal of Psychology, Jul 1935, in which he states he was the first person to suggest the idea of correlations between persons, as well as the many difficulties in the way of this; and a letter he received from Dr William Stephenson, which has not survived in the collection.
He refers to the work of Burt, specifically in relation to correlating two people who have been given different tests, illustrating his points with calculations throughout.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11782021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/8http://127.0.0.1:8081/repositories/2/archival_objects/1178Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)10 (37), Thomson to Ledermann, 19 Jul 193719 Jul 19371 letter (2 leafs, 2 sides)engEnglishThomson continues to discuss Burt's paper, The Correlation between Persons, from the British Journal of Psychology, Jul 1937, providing an alternative to Burt's formula, which he criticises as being unnecessarily complex.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11792021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/9http://127.0.0.1:8081/repositories/2/archival_objects/1179Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)11 (37), Thomson to Ledermann, 20 Jul 193720 Jul 19371 letter (1 leaf, 2 sides)engEnglishThomson continues to discuss Burt's article, The Correlation between Persons. He reproduces equations Ledermann sent in response to his previous letter, and asks him to clarify them.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11802021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/10http://127.0.0.1:8081/repositories/2/archival_objects/1180Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)12 (37), Thomson to Ledermann, 25 Jul 193725 Jul 19371 letter (1 leaf, 1 side)engEnglishThomson gives Ledermann his address at the Training College, Bingley, for the following fortnight, informing him he will be lecturing there and asking him to write. He also mentions an enclosed cheque, which has not survived in the collection, asking Ledermann to sign and return it.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11812021-05-26T16:29:28ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/11http://127.0.0.1:8081/repositories/2/archival_objects/1181Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)13 (37), Thomson to Ledermann, 6 Aug 19376 Aug 19371 letter (2 leafs, 4 sides)engEnglishThomson advises Ledermann to keep the letters he sends him for future reference. He discusses a paper he has written for the British Journal of Psychology, which regards the influence selection has over factorial analysis, and asks Ledermann if he should shorten it.
He advises Ledermann to make use of some of the concepts for a paper of his own regarding matrix notation, and refers him to work of Hotelling, Thurstone, and Aitken, particularly Aitken's paper, Note on Selection from a Multivariate Normal Population, from Proceedings of Edinburgh Mathematical Society, 1935.
Thomson also discusses the possibility of locating a copy of Darmois’ Statistique Mathematique, and informs Ledermann of his plans for the next few weeks, which include returning to Edinburgh then possibly staying at Glenapp in Ayrshire.Open.Papers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11822021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/12http://127.0.0.1:8081/repositories/2/archival_objects/1182Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)14 (37), Thomson to Ledermann, 14 Aug 193714 Aug 19371 letter (2 leafs, 2 sides)engEnglishThomson refers to a proof or article which he had enclosed. This has not survived in the collection. He does not name the author, but suggests to Ledermann that he may want to contact him, either sending the letter by the fastest ship or communicating by cable, charging the costs to the Carnegie fund.
He refers to his British Journal of Psychology article discussed previously; highlighting that he wishes it to be understood by less mathematical readers, and encouraging Ledermann to follow it with a more mathematical one.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11832021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/13http://127.0.0.1:8081/repositories/2/archival_objects/1183Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)15 (37), Thomson to Ledermann, 16 Aug 193716 Aug 19371 letter, (1 leaf, 2 sides)engEnglishThomson informs Ledermann that he has submitted his paper to the British Journal of Psychology, and has included a referral to a future article of Ledermann's.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11842021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/14http://127.0.0.1:8081/repositories/2/archival_objects/1184Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)16 (37), Ledermann to Thomson, 18 Aug 193718 Aug 19371 letter (3 leafs, 3 sides)engEnglishThomson tells Ledermann how pleased he is that he is that Ledermann is going to follow up his [Thomson's] paper for the British Journal of Psychology, and asks him to include material regarding multivariate selection.
He talks about the various reading he has undertaken, referring to work by Bocher, Hotelling, and Turnbull; and discusses the connection between the correlation of orthogonal vectors produced by selection in the population, and the correlation of orthogonal vectors produced by estimating them from insufficient equations.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11852021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/15http://127.0.0.1:8081/repositories/2/archival_objects/1185Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)17 (37), Thomson to Ledermann, 25 Aug 193725 Aug 19371 letter (1 leaf, 1 side); 1 handwritten manuscript, (14 leafs 14 sides)engEnglishThomson informs Ledermann that he has sent Ledermann's paper to the British Journal of Psychology, with some minor corrections. He tells Ledermann he should take some time off when his Mother visits him, and apologises for not being able to invite him to Glenapp.
Also includes a manuscript, numbered 17a (37) which Thomson sets a problem for Ledermann, asking him in his letter if he can provide a proof.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11862021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/16http://127.0.0.1:8081/repositories/2/archival_objects/1186Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)18 (37), Thomson to Ledermann, 29 Aug 193729 Aug 19371 letter (6 leafs, 6 sides)engEnglishThomson thanks Ledermann for his response to his previous letter, stating how neat his proofs are and discussing them at length. He refers to a paper of Aitken's published in the Edinburgh Mathematics Society, series 2, vol. 4, part II, and explores how the formula therein can assist them. The letter is unsigned, so appears to be incomplete.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11872021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/17http://127.0.0.1:8081/repositories/2/archival_objects/1187Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)19 (37), Thomson to Ledermann, 14 Sept 193714 Sept 19371 letter (6 leafs 6 sides)engEnglishThomson stresses that he does not wish Ledermann to reply to the letter while his Mother is visiting. He refers to a manuscript he sent Ledermann regarding the connection between estimation and selection, outlining a point he can add to it and referring to matrices of Aitken's.
He discusses orthogonal projection, estimation of regression, the selection formulae, and how these can be seen as one; as well as the division of factorial analysis after selection into two parts.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11882021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/18http://127.0.0.1:8081/repositories/2/archival_objects/1188Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)20 (37), Thomson to Ledermann, 15 Sept 193715 Sept 19371 letter (12 leafs, 12 sides)engEnglishThomson writes to Ledermann regarding the method of sums of differences, which Thomson uses frequently in his work but with which Ledermann is unfamiliar.
He refers Ledermann to a 1909 paper of Spearman's in which the method was first used, and explains the form of the method he himself has used since, which he refers to as the pooling square. He goes on to discuss Hotelling's paper on the most predictable criterion in the Journal of Educational Psychology.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11892021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/19http://127.0.0.1:8081/repositories/2/archival_objects/1189Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)21 (37), Thomson to Ledermann, 26 Sept 193726 Sept 19371 letter (1 leaf, 2 sides)engEnglishThomson thanks Ledermann for his letters, and discusses his study of the problem of estimation, referring to the work of Bartlett. He also informs Ledermann that he has ordered Darmois' book, Methodes d’ Estimation, and asks him if he thinks it worthwhile buying a copy of Cullis’ Matrices and Determinoids.
Thomson advises Ledermann to keep account of postage and expenditure so he can be reimbursed for these, and informs him of his whereabouts for the next few months in order to arrange a meeting time.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11902021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/20http://127.0.0.1:8081/repositories/2/archival_objects/1190Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)22 (37), Thomson to Ledermann, 30 Sept 193730 Sept 19371 letter (10 leafs, 10 sides)engEnglishThomson discusses M S Bartlett's proposed method of estimating factors as given in his British Journal of Psychology articles of Oct 1935 and Jul 1937. Thomson interprets the method, with the letter containing several pages of working for Ledermann's comments.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11912021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/21http://127.0.0.1:8081/repositories/2/archival_objects/1191Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)23 (37), Thomson to Ledermann, 1 Oct 19371 Oct 19371 postscript (3 leafs, 3 sides)engEnglishPostscript following on from Thomson's previous letter in which he expounds further upon his interpretation of M S Bartlett's proposed method of estimating factors.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11922021-05-26T16:29:36ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/22http://127.0.0.1:8081/repositories/2/archival_objects/1192Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)24 (37), Thomson to Ledermann, 4 Oct 19374 Oct 19371 letter (7 leafs, 7 sides)engEnglishThomson discusses his way of calculating what values may be given to the elements of Vpp in a hierarchical matrix, illustrating this with several pages of working for Ledermann's comment.Open.Glenapp Ayrshire ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11932021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/23http://127.0.0.1:8081/repositories/2/archival_objects/1193Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)25 (37), Thomson to Ledermann, 4 Oct 19374 Oct 19371 small postcard (2 sides)engEnglishSmall postcard regarding Ledermann's comments on Thomson's use of the auxiliary matrix.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11942021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/24http://127.0.0.1:8081/repositories/2/archival_objects/1194Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)26 (37), Thomson to Ledermann, 8 Oct 19378 Oct 19371 postcard (2 sides)engEnglishPostcard acknowledging Ledermann's letter regarding Bartlett's estimates, which Thomson doubts have the minimum standard error. He discusses the error variances of the regression estimates, referring to a numerical example he has sent.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064oai:archivesspace:/repositories/2/archival_objects/11952021-06-08T11:33:24ZUniversity of Edinburgh Library Heritage CollectionsUniversity of EdinburghColl-1064/25http://127.0.0.1:8081/repositories/2/archival_objects/1195Thomson, Godfrey Hilton, Sir, 1881-1955 (psychologist and Bell Professor of Education, University of Edinburgh)27 (37), Thomson to Ledermann, 16 Oct 193716 Oct 19371 letter (3 leafs, 3 sides)engEnglishThomson asks Ledermann for his opinion on Thomson first draft of his section of their multivariate paper. He asks for Ledermann's advice on a few areas in particular, listing them and any potential problems he thinks may arise.Open.Edinburgh -- ScotlandPapers of Professor Walter Ledermann, Coll-1064eyJtZXRhZGF0YV9wcmVmaXgiOiJvYWlfZGMiLCJmcm9tIjoiMTk3MC0wMS0wMSAwMDowMDowMCBVVEMiLCJ1bnRpbCI6IjIwMjYtMDYtMDEgMDM6MTM6MjYgVVRDIiwic3RhdGUiOiJwcm9kdWNpbmdfcmVjb3JkcyIsImxhc3RfZGVsZXRlX2lkIjowLCJyZW1haW5pbmdfdHlwZXMiOnsiUmVzb3VyY2UiOjAsIkFyY2hpdmFsT2JqZWN0IjoxMTk1fSwiaXNzdWVfdGltZSI6MTc4MDI4MzYwODIzMX0=