Central Location Testing (CLT)
Controlled conditions. Senior expertise on site. Every single study.
When Kantar and Ipsos need flawless on-site execution, they trust us to run the room. CLTs only works when the environment is right, the product handling is precise, and the team on the ground knows exactly what they’re doing. That’s why every single CLT study has a senior Zest project manager on site, no exceptions, and the operational infrastructure to match.
How We Deliver
A CLT has one fundamental promise: controlled, consistent, repeatable conditions that give you data you can trust. Delivering on that promise means owning every variable, the venue, the setup, the product preparation, the respondent flow, the protocols, and the people managing all of it on the day.
We take full ownership of every element, from the first venue search to the last unit of excess product leaving the building.
One team, one standard, zero handoffs.
01Recruitment & Participant Management
02Venue Sourcing & Setup
03On-Site CLT Delivery
04Post-Trial Wrap-Up
Recruitment & Participant Management
CLT recruitment demands more than standard qual criteria. Participants need to be reliable, punctual, and genuinely right for the study, because in a controlled environment, the wrong person in the wrong slot disrupts everything.
- Targeted recruitment including niche categories
- Allergy & safety screening
- Validation calls for behaviour, articulation, and reliability
- Product ownership checking (photos, videos & experience)
- Clear briefings, reminders, and ongoing comms
- Dropout management & respondent retention
- Management of survey hosting platforms
Venue Sourcing & Setup
The right venue isn’t just a room, it’s a controlled environment designed around the study. We source, book, and set up venues that fit the specific demands of every trial.
- Venues sourced to fit trial logistics and methodology
- Organisation of refrigeration & specialist equipment
- On-site room setup for ideal test conditions
- Signage, flow planning & controlled respondent movement
On-Site CLT Delivery
This is where the operation lives or dies, and it’s where Zest is at its strongest. Every study has a senior project manager on site. No exceptions.
- Senior Zest Project Manager present at every CLT day. No exceptions.
- Protocol enforcement (temperature, prep, rotations)
- Briefing and managing CLT staff
- Monitoring test timings and respondent flow
- Troubleshooting issues instantly
- Multiple location management
Post-Trial Wrap-Up
A clean close matters as much as a clean start. We handle everything after the last respondent leaves.
- Excess product storage or returns
- Certified destruction and recycling of products
- Incentive management
Zest Spotlight: Central Location Testing
100 premium beer drinkers. A temperature-sensitive product. A mid-session protocol adjustment that could have derailed everything. It didn’t. 95 of 100 completed take-home follow-ups, exceeding the client target. The Ipsos team celebrated by taking us out for beers. The next brief landed within weeks.
30 participants. One day. A testing process rigorous enough for Clearcast approval. We designed and delivered every element — recruitment, scripting, session management, and day-after follow-up — so i-BRATE had the proof they needed to take their product to TV.
220 participants screened, scheduled, and seen across two UK locations in five days, every one of them swallowing a pill under the supervision of a first aid trained Zest team. Complex, sensitive, high-stakes. Exactly the kind of brief we’re built for.
1,200 UK consumers. Three cities. A hard seltzer category about to launch. Ipsos needed flavour data they could trust at scale, so Zest built a hospitality-grade operation from the ground up, piloted it at The White Rooms in St Albans, and delivered it across London and Leeds without a session going off-track.
