He was educated at Queen's Park School in Glasgow and entered the University of Glasgow as a student in October 1918. At the end of his first year he was awarded the Sir Walter Scott Bursary in Arts and graduated M.A. with First Class Honours in Mathematics and Natural Philosophy in 1922. The following year he graduated B.Sc. (old regulations) with distinctions in these two subjects.
In October 1922 he was awarded the Euing Scholarship of £100 per annum for three years. Under the terms of the scholarship he was required to assist the Professor of Mathematics, the late Professor G A Gibson. At this stage in his career Robb's main academic interest was in astronomy. In 1926 he was awarded a Commonwealth Fund Fellowship and went to the University of Michigan, taking his M.Sc. degree two years later and then returning as a Lecturer to Glasgow. He was elected a Fellow of the Royal Society of Edinburgh in 1929 and of the Royal Astronomical Society in 1931. In 1936 he obtained the D.Sc. degree for a thesis entitled 'Studies in Stellar Statistics with particular reference to Type A stars'. Before this he had also spent some time as a postgraduate student at the University of Lund in Sweden.
As part of his duties in the Department of Mathematics, Robb gave lectures on statistics and, over the years, he expanded this subject by providing new courses. In 1935 he introduced statistical options for Honours students and in 1944 was appointed Mitchell Lecturer in Statistics. He was also instrumental in creating a new Honours combination of Political Economy and Statistics. By 1950 a sub-department of statistics under Robb had been formed and from then on his teaching duties were confined to this subject.
As the title of his D.Sc. thesis indicates, Dr Robb came into statistics by way of astronomy and he published a number of papers between 1930 and 1938 in which he applied statistical techniques to astronomical problems. When Professor Ludwig Becker died, and before the appointment in 1937 of the late Professor W M Smart to the Regius Chair of Astronomy, Robb acted as Head of the Astronomy Department.
In the years that followed it was not only to astronomical questions that he applied his knowledge of statistics. A constant stream of research workers in every branch of science, and particularly in medicine, came to him for advice and help, which he gave willingly without asking for recognition or even acknowledgement. His friends sometimes suspected that quite a number of articles and dissertations, that won their authors praise and preferment, represented work essentially done by Dr Robb. The Faculties of Arts and Science also benefited from his advice and from his analyses of the progress of students in relation to their entrance qualifications. All this work, together with the supervision of research students, was undertaken cheerfully by Dr Robb without complaint, although it left little room for the prosecution of his own scientific interests. He was appointed to a Senior Lectureship in 1948 and retired in 1966.
Dr Robb never thrust himself into the limelight, and some of his colleagues may not have realized that in his day he was a distinguished athlete. He participated in amateur athletics throughout his active working life. In 1928 he was a member of the British sprint team in the Olympic Games held in Amsterdam and he held several Scottish sprint titles. He won the Scottish 100 yards sprint, beating the favourite, Jimmy Walker of Queen's Park. He was essentially a track man. While in Michigan as a post-graduate student he was not permitted to compete, but assisted in the pacing of the negro Eddie Tolan, who later became an all-American champion. He also played hockey and was a member of the University First Eleven, obtaining his Blue in 1922. For over thirty years he took an active part in the affairs of the Glasgow University Athletic Club and was at one time Chairman of the Athletic Grounds Management Committee. He also served for a time as judge for the Scottish Amateur Athletic Association.
Dr Robb will be long remembered with gratitude by his colleagues and friends as a modest and cheerful man who was always willing to put his considerable talents at the disposal of others without stint and with a minimum of fuss.