A lot does come down to how the company in question defines what they want from a test. I agree with some of your views Paxboy that if a company sets a requirement for every candidate to be of a specific type then they are in danger of getting a workforce which is particularly, how shall I put it, 'bland'.
What they are trying to do is weed out those that are totally unsuitable due to their results, thus getting the numbers down to a sensible level for taking the process further. I can't see any problem in that, just like I can't see any problem in them rejecting candidates due to low scores in an aptitude test or interviewing badly. It's all part of the process.
Here's an extract from jobs.financialdirector.co.uk which I think explains the processes quite effectively;
Psychometric testing
An introduction
Psychometrics is a loosely used word that has created a whole industry of occupational testing and employee assessment. It covers a variety of tests that are used to assess the character strengths and weaknesses of a candidate, providing accurate profiles of their suitability for a position.
What are psychometric tests?
Psychometric tests are often used by employers as part of their selection process. Basically, psychometric tests are tools for measuring the mind ('metric' = measure; 'psycho' = mind). There are two types of psychometric tests:
Aptitude tests: which assess your abilities
Personality questionnaires: which help to build up a profile of your characteristics and personality
How are they used by employers?
Employers can use these tests at any point during the selection process. Sometimes they are used at the beginning, as a way of screening out unsuitable candidates. Other employers prefer to use them towards the end of a selection process.
But don't panic; psychometric tests are almost always used in conjunction with more traditional selection methods, such as a one-to-one interview. This means that even if you don't do brilliantly with psychometric tests, you can still impress the selectors in other ways.
Why are they used?
Many employers believe that psychometric tests give an accurate prediction of whether you are able to do the job and whether your character is suited to the work. Research shows that, statistically speaking, psychometric tests are one of the most reliable forms of revealing whether or not a candidate is suitable for a job.
How can I prepare for the tests?
Unlike GCSEs and 'A' levels, psychometric tests are not testing your knowledge or memory. They are testing your aptitude for various tasks or trying to reveal a more accurate assessment of your personality and temperament in the workplace. However, it does pay to familiarise yourself with typical questions, particularly in aptitude tests. Quite often a mediocre score can be vastly improved with practice.
Aptitude tests
Also known as cognitive, ability or intelligence tests, these do not examine your general knowledge but test your critical reasoning skills under strictly timed conditions. There are many different types of tests depending on the type and level of job you're applying for. However, a typical test might have three different sections each testing a different ability e.g. verbal reasoning, numerical reasoning and diagrammatic or spatial reasoning. Typically, the test would allow 30 minutes for 30 or more questions.
Your score on these tests is compared to a 'norm group' which is usually made up of current jobholders who have done this test in the past. Employers can set their own standard in terms of how well you have to do in comparison with the 'norm group' in order to 'pass'. But as a general rule of thumb you should try to complete 70 – 80 per cent of the questions and aim to correctly answer at least two thirds of those which you've answered.
Personality questionnaires
Even if you score well in aptitude tests, this doesn't necessarily mean that you will be suited to a job. You can be good at something, but hate doing it! Success in a job also depends on your personal characteristics and qualities. Personality questionnaires can measure these.
Questions focus on a variety of personality aspects such as:
How you relate to other people
Your work style
Your ability to deal with emotions (your own and other people's)
Your motivation, determination and general outlook
Your ability to handle stressful situations
Unlike aptitude tests, there are no right and wrong answers, although occasionally there is a time limit. Selectors will not be looking for a particular type of 'profile' but certain characteristics which are suited to the job.
How should I answer the questions?
Many employers want candidates with a balance of personal qualities: for example, being able to get on with people, take charge and organise, and being focused on achievement. But don't try and second guess the answers that they want. There are often checks within questionnaires to detect whether you are giving a false picture of yourself. Corny as it sounds, it's probably best just to be yourself: ultimately neither you nor the employer will be happy if the real you is not on display at work.
So again I'll say it, like it or not these tests do give results which an employer who is using them can base part of his 'suitability' decision on. I'm sure you can give the impression that you are something that you are not, but lets face it, people have been doing this for years in interviews. The psychometric test is just another tool to try and weed these candidates out and to find what they are really like, yes I agree, maybe by using a slightly more scientific method. Why should you have a problem with that? You don't have a problem with the doctor using ever more scientific methods to ascertain your health every 12 months?
A good candidate is a good candidate and will do well in a selection process. I'm sure you'd agree that a good candidate is prepared for what they are going to face during selection through preparation and someone who oozes natural ability but doesn't bother preparing only to not show their best can only be classed as an unsuitable candidate. What we have to remember, especially in our industry is that the competition for flying jobs is intense and the supply outstrips the demand. All the time that this prevails (and I'm lead to believe by the older and bolder that this is always the case in aviation) then there will be a plentiful supply of suitable candidates, even when the chaff have been removed by these selection tests, so you really must do yourself justice by giving yourself the best chance of success.
PP