You will not be surprised to hear that tests form a major part of the application process for graduate jobs. Still, different companies and industries challenge you in particular ways, so one major skill is adapting to the situation, which will definitely come with practice.
Companies have historically asked candidates to take verbal reasoning and numerical tests. In this ever evolving digital age, tests are now usually online, but as you progress through the application stages, you will be invited to the office to do other exercises. The activities could test how well you work in groups, your leadership skills and how efficiently you respond to emails in your inbox (sometimes referred to as 'in-tray' or 'e-tray' exercises). In a way the in-tray exercise is the easiest since you can practise using online tests in advance and at least gain some idea of what to expect.
A more recent trend has been the rise in situational judgment psychometric tests. The aim of these tests is to provide hypothetical situations that require decisions to be taken and selection of one of the different possible responses. The key is to settle on the most appropriate course of action using both your judgment and a logical way of thinking. This is one of the most representative tests in the application process, since it really puts you in the shoes of an employee. Once you progress to the latter stages, you will be able to use this experience in practice. Still, group and leadership exercises will be harder to anticipate and to an extent depend on how you work with other people on the day.
In all careers, you need to work well with other people, often those who you do not know that well at first, and then develop a good working relationship. Also, as you gain experience, you will have the chance to coach junior staff and so the interviewers want to see that you have both the right skills and attitude to lead a team and resolve any conflicts within it. Thinking on the spot will be difficult, especially under the pressure of an assessment day, but you need to ensure that you voice your own point of view without being too domineering. Leaders give consideration to opinions from all team members and then decide on the necessary way forward. Not taking enough notice of others will make an unfavourable impression on the whole.
Overall, the key to success is really imagining that you actually work for the company and you are making decisions to resolve issues that you would encounter on a daily basis. If you provide sensible answers and work well in a team, then there is no reason why you can't impress the interviewer and make a success of your application tests and assessment centres!
Arnab Datta