Traditional interviews by senior managers and senior technical staff have emerged as the best way to choose recruits, according to a new BCS book, Professional Issues in IT.
A variation on this theme is panel interviews, but these tend to favour smooth-talkers, said author Frank Bott, who has worked in the software industry and as a professor of computing science in the UK and the US.
"The panel may contain a majority of people who are neither professionally competent nor operationally involved," he said. "Independent panel members are thought to help prevent nepotism and corruption but evidence suggests they are often responsible for bad appointments."
References are being used less often, said Bott, because legislation allows people to see what has been written about them and sue for damages. Employers who feel they have been misled by a reference can also sue.
Bott also raised questions over psychometric tests. These fall into three categories:
lAbility tests measure verbal, numerical and general skills.
lAptitude tests measure potential to learn skills needed for the job and have been used widely for recruiting trainee programmers. These tests can be "fairly effective," said Bott, but the results are questionable if candidates have had the chance to practice, which he said is usually the case. In addition, it is difficult to design good tests for higher-level skills.
lPersonality tests aim to assess characteristics that significantly affect how someone might behave in relationships with other people. "Unfortunately there are several competing theories of personality and although the tests are widely used their value is far from clear," said Bott.
Situational assessments are often used by big companies when recruiting graduates. Shortlisted candidates are put through various situations together and are assessed. This is expensive, said Bott. He believes a variation on the theme can be used in traditional interviews, with the interviewer asking what the candidate would do in a particular situation.
Task assessment is a variation on situational assessments and aptitude tests. Candidates are asked to carry out some of the job tasks, such as writing a program.
"This works very well if the tasks lend themselves to being assessed in this way," Bott said. "The trouble is that where a job involves some skills that can be assessed in this way and some that cannot, the former tend to be over-emphasised. So ability to write a short program can be easily assessed but ability to write a 2,000-statement program cannot: it would take too long."
To the list of formal methods of recruitment Bott adds nepotism and cronyism. "Cronyism in particular should not be rejected as unfair or ineffective," he said. "If one has worked with a person before and seen they are effective in the role one is looking to fill, then offering them the job is a low-risk way of filling it."
Top of Bott's list for recruiting staff is a series of traditional individual interviews with senior management and senior technical staff. The drawback is that this approach makes it difficult to show whether equal opportunities legislation has been complied with. But, Bott said, "This can be a very reliable method of selection, particularly if records are kept so you can go back and see how effective each interviewer's judgement has been."
Professional Issues in IT covers topics including the nature of a profession, financing a start-up company, intellectual property rights and data protection. It costs £20, or £15 to BCS members.