Expedia Inc has created a "usability lab" based in London, its first outside of the US.
The role of the lab is to study consumer behaviour in terms of how they research and book travel via Expedia websites and applications.
Research carried out by the group, which includes Expedia, Hotels.com and Venere, earlier this year reveals the stress of booking a holiday compares with being stuck in traffic or a bad day at work.
In addition, 28% of consumers feels the internet has made booking travel more confusing because of the huge choice.
Expedia says it is employing "scientific methodology" via eye-tracking and electromyography technology, whereby sensors are placed on the cheek and eyebrows of users to test changes in facial muscles.
The changes are then analysed to discover the impact on the booking.
The company has used similar technology at its lab in the US which opened earlier this year.
The lab will also enable Expedia to test new products such as its Scratchpad functionality, which was developed when the company noted people writing down prices.
A lab in Singapore is also planned this year.
NB: Test tubes image via FreeImages.