DISCUSSION

Questions put to Mr Aitchison during the evening dealt mainly with the method of his SDI investigation. In reply to Mr C. S. Sabel (Central Electricity Generating Board) Mr Aitchison said that progressive modification of user profiles would be attempted. In answer to a point made by Mr D. V. Arnold (ICI Heavy Organic Chemicals Division) he affirmed his belief that co‐operation with librarians was essential. Mr P.E.Colinese (Central Electricity Generating Board) asked about the method of assessment of relevance by users. Mr Aitchison indicated that this would become more stringent as the study progressed. In reply to Mr D.H. Barlow (McGraw Hill) he said that three indexers would be required for indexing a maximum of 15,000 documents a year. To questions on the amount of computer time required and the percentage of key word match which would enable him to regard a document as relevant to a user, he replied that they hoped to have answers within the next four months. Mr C. S. Sabel (Central Electricity Generating Board) wondered what was the best way for work on mechanization to be co‐ordinated. Mr Aitchison thought that since so few people were working in this field there was little risk of fruitless duplication of effort.