Very poor graduate recruitment process.
The main issue is that they request only those applying to the R&D and Engineering graduate schemes to travel to Mars for an interview prior to the main assessment centre. The reason for this is (as stated on the graduate schemes section of their website) so you can do a 'technical exercise'. Instead, this preliminary interview consists of performing a 10 minute pre-made presentation plus follow up questions, and then finally some general situational/behavioural questions. This preliminary interview is flawed for several reasons:
1) Conducting a short and relatively simple presentation is quite frankly NOT a proper technical exercise. It really isn't a good way to show the interviewers that you have the (presumed) technical ability required to succeed in an R&D/Engineering role. The 'technical exercise' should instead involve problem-solving, such as in a group exercise, which leads me on to my next point:
2) We were told in the email inviting us to the preliminary interview that there would be a group exercise during the day. This turned out to be a communication error, which quite frankly reflects Mars' general lack of care surrounding their graduate recruitment process. What made this incident even worse and unacceptable is that I learned during the day that one of the other candidates, who had been to the preliminary interview during the previous year, had assumed it was a mistake, and after calling up Mars to point out their potential error, received confirmation that it was a mistake. Despite the mistake being pointed out to Mars, no effort was made to inform the other candidates such as myself that it was a mistake, meaning we wasted valuable interview preparation time on group exercise research.
3) This penultimate stage of the recruitment process is accessed far too easily. Unlike most other blue-chip graduate schemes, you only have to do one aptitude test. This is a logic (patterns) test which is made far too easy as it is untimed, with no penalty for taking too long, as I took 2 hours to answer 12 questions and clearly wasn't punished for such a slow time. Mars should instead set at least 2 tests, i.e. numerical and logical, and have them timed. Rank candidates on time and number of correct answers so that you more accurately assess the technical ability of the candidates.
4) This stage should NOT be an on-site interview. It is financially irresponsible of Mars to request cash-strapped students to visit their Leeds/Slough site twice during the recruitment process. Nearly every other graduate scheme recruitment processes' penultimate stage is a video interview, which in general seem to be better at assessing candidates than Mars' preliminary interview. Many people live far away from Mars' sites and so require expensive train tickets and a night at a hotel. Mars' maximum reimbursement of £75 simply isn't enough, I have actually reached this interview stage twice and both times have been £70-80 out of pocket AFTER the reimbursement.
5) Mars are not at all clear with regards to how technical/sciencey you should base your presentation/answers on, which is unfair considering that you are applying to an R&D position. I say this because for my first application, the interview required a behavioural-based presentation, and then I was later asked to discuss an aspect of my degree. I didn't have a good answer prepared, and ended up being rejected which was fair enough. Conversely, for my second application, the focus of the presentation was a project you had worked on, and so the obvious topic was my final year science research project. I was assigned a main interviewer who several years ago did Maths (as opposed to Chemistry) at University. This seemed to have doomed my presentation from the start as despite watering down the theory to very basic concepts, the interviewer (quite surprisingly) couldn't seem to follow the theory. The fact that the interviewer was nodding in agreement at my further attempts to simplify the theory, despite the fact in hindsight they still didn't understand the concepts, was misleading and unprofessional.
6) Adding to point 5), I think overall the biggest flaw with this penultimate stage is that it is simply too short and basic, meaning there isn't much to assess candidates on, and so they are rejected for very minor/arbitrary reasons.
In summary, Test candidates more thoroughly before the interview stages, communicate more effectively, convert the penultimate stage interviews into more traditional video interviews with more relevant questions, and also clarify how scientific/technical your application should be (i.e. stressing to candidates that despite it being an interview for a Sciencey R&D role, your interviewers may well not understand relatively basic science as they [surprisingly] can't guarantee to give you an interviewer who did the same degree [one of Chemistry/Biology/Physics/Maths] as you!).
