3 Discuss the advantages and disadvantages of rolling group discussions where a large number of respondents enter and leave the group as it progresses and their departure time arrives. What other ways are there of gathering such data?

Birmingham International Airport (BIA) has enjoyed consistently high levels of customer satisfaction since measurement began. Passengers have always rated BIA more highly than its nearest serious competitors – Manchester, Heathrow and Gatwick –
on all key measures: ease of access, staff attitudes, speed of processing and the provision of facilities. BIA has become the airport of choice for many in the West Midlands and from further afield.
The measurement of customer satisfaction has been taken in the traditional UK airport way: specially trained and security-passed interviewers circulate in the airport, interviewing a representative sample of passengers, asking them to rate their satisfaction with each factor. All major airports in the UK operate exclusive fieldforces, providing a data collection facility for internal purposes that remains consistent and sensitive to the special circumstances of airports and their customers.
It became clear, however, that BIA risked becoming a victim of its own success.
Increasing numbers of passengers were keen to use BIA as their preferred gateway, airlines had seen the benefits of offering services direct to the UK’s second city, and the local authority that controlled the airport at the time was keen to benefit from the increased revenue opportunity such expansion offered. This was a compelling case, and plans for expansion were made.