Why Assessment Days Matter in 2025

If you’re chasing a graduate marketing role in the UK, chances are you’ll face an assessment day. Whether you’re applying to Omnicom, Dentsu, Havas, WPP, or a mid-size agency, assessment days have become the ultimate filter. Employers use them to test not just your CV skills, but how you think, communicate, and collaborate under pressure.

Recent research from the Institute of Student Employers (ISE, 2024) shows:

• 62% of graduate schemes use assessment centres.
• 41% of marketing agencies include group exercises and case studies.
• Candidates who actively prepare improve their pass rate by 35%.

Our guide gives you a battle-tested roadmap to stand out at every stage.

1. What to Expect on an Assessment Day

Assessment days often last half a day to a full day. Expect:

• Welcome & Icebreaker – meet other candidates, first impressions count.
• Group Task – usually a marketing problem to solve collaboratively.
• Case Study / Business Simulation – e.g., launching a product or planning a campaign.
• Presentation – pitch findings to assessors.
• Role-Play – client or stakeholder scenario.
• Aptitude/Psychometric Tests – numerical, verbal, situational judgement.
• Interview – final behavioural/competency round.

Recruiter Insight (Oxford Careers): “Recruiters aren’t looking for the loudest voice, but for those who balance confidence with collaboration.”

2. Group Exercises Explained (and What Recruiters Look For)

Group exercises test your ability to:

• Contribute ideas without dominating.
• Build on others’ points (active listening).
• Stay calm under time pressure.
• Work towards consensus.

Example:
You’re given a brief: “Plan a launch campaign for a new sustainable fashion brand with a £50K budget.”

Good behaviours:

• Suggest structure (“let’s split into channels: digital, events, partnerships”).
• Invite quieter voices to speak (“Alex, what’s your view on the social plan?”).
• Use numbers from the brief (“if TikTok ads are £5 CPM, £10K spend = 2M impressions”).

🚫 Avoid: dominating, ignoring instructions, being negative.

Checklist: Recruiters Score You On…

• Teamwork & leadership
• Problem-solving
• Communication clarity
• Commercial awareness
• Time management

3. Case Studies & Marketing Simulations

At Omnicom/Dentsu, expect marketing case studies.

Example Case Study Prompt:
“Your client is a UK food delivery start-up with £250K ad spend. Design a cross-channel plan to drive 10K new users in 6 months.”

Winning Approach:

• Situation/Task: Clarify objectives (CAC < £25, targeting Gen Z).
• Action: Propose a mix (TikTok ads, influencer partnerships, campus events).
• Result: Show potential ROI (TikTok 3M reach, CAC £20).
• Follow-up: Mention risk mitigation (diversify channels, A/B test).

Recruiter Note (Havas Group): “We don’t expect perfection, we want to see structured thinking and commercial logic.”

4. Role-Plays & Client Scenarios

Often, you’ll act as an Account Executive in a client meeting.

Example Role-Play:
A client is unhappy with low engagement on Instagram. You must present data and suggest improvements.

• Use data: “Your CTR is 0.7%, industry benchmark is 1.2%. By shifting £5K into Reels ads, we project 30% uplift.”
• Stay calm if client pushes back.
• Show empathy + solutions.

5. Psychometric & Aptitude Tests

These may include:

• Numerical Reasoning – interpreting campaign ROI tables.
• Verbal Reasoning – analysing text about market trends.
• Situational Judgement – “How would you handle a conflict with a teammate?”

Stat (SHL, 2024): Candidates who practice online beforehand score 25% higher.

6. Presentation Skills Under Pressure

You may need to present your case study in 5–10 minutes.

Tips:

• Use 3-part structure (Problem → Solution → Impact).
• Keep slides clean (max 6 words per line).
• End with ROI figures (“Campaign projected ROI: 3.5:1”).

Omnicom Recruiter Quote: “We’re less interested in flashy slides, more in how clearly you sell your story.”

7. Virtual vs In-Person Assessment Days

Since COVID, 60% of UK assessment centres run virtually (ISE, 2024).

Differences:

• Virtual → focus on camera presence, digital collaboration (Miro, Teams).
• In-person → body language, presence, networking at breaks.

8. Recruiter Insights: Havas, Omnicom, Dentsu

• Havas: Value creativity + storytelling.
• Omnicom: Assess structured problem-solving.
• Dentsu: Prioritise digital-first thinkers.

9. Common Mistakes Candidates Make

❌ Talking too much, not listening.
❌ Ignoring numbers/data.
❌ Forgetting time management in group tasks.
❌ Overcomplicating answers.

10. Templates, Checklists & Scripts

Assessment Day Checklist

• Practise case studies with timers.
• Prepare commercial awareness (latest TikTok, Meta, Google Ads news).
• Mock group exercise with friends.
• STAR/SHER stories ready.
• Presentation structure template.

Networking Script (after assessment day):
“Hi [Recruiter], thanks again for today’s assessment. I really enjoyed the group task on [topic] and learning how your team approaches [area]. I’d love to stay in touch regardless of the outcome.”

Conclusion

Assessment days are your chance to prove you’re more than a CV. By showing structured thinking, teamwork, and commercial logic, you’ll separate yourself from 90% of candidates.

Subscribes and get an Assessment Day Pack (Case Study Template + 10 Group Exercise Hacks + STAR/SHER sheet) 

References

• Institute of Student Employers (ISE) (2024). Graduate Market Report. London: ISE.
• Oxford University Careers Service (2023). Assessment Centres.
• Havas Group (2023). Graduate Careers Blog.
• Omnicom Media Group (2024). Recruitment Insights.
• Dentsu Aegis Network (2023). Graduate Programme Guide.
• SHL (2024). Psychometric Testing Trends.

Read previous: The Graduate Interview Bible for Marketing Roles (2025 Edition)

Read Job Hunting Series: Series 1: UK Job Market Glossary 2025: Essential Vocabulary Every Graduate and International Student Must Know