Psychometric tests- what are they?

In the last 20 years there has been a massive explosion in the use psychometric tests in organisations, but what are they and why do people have to do them? The words broken down mean psycho is the Greek word for mind and metric- is the Latin word for measure, therefore the word psychometric is a way to measure the ability of an individuals mind. Psychometric tests have been used increasingly in the  They have  twentieth century, from career counselling  to military selection and it is said that over 100,000 of such tests are used in the west everyday.

So what's the is the purpose of them? These tests give organisations an additional way to distinguish between normal candidates and exceptional candidates, also they are supposed to be (when used in combination with other methods) the best prediction of job performance. They are divided into 3 groups, tests of ability ( general mental ability/ intelligence) Interest (career development/ career choice) and Personality assessments (trying to distinguish personality traits and behaviour).

They are a big business and immensely popular, soon trainee teachers will be doing them as part of PGCE assessments soon, most graduate jobs use them to differentiate between candidates. However, they aren't without problems, they have been criticised for being culturally and racially biased in terms of "intelligence tests" (Read about Hernstein and Murry's book the bell curve). Also Some personality assessments have been criticised for being "fake-able". However I cannot deny these are extremely common place in many organisations and my advice to you is to get savvy, and practice, practice,  practice.

Here are some links to some information and practice sites:
http://www.psychometricadvantage.co.uk/
http://www.psychometric-success.com/
Prospects