Routes to Measurement

Many events organisers will already have access to attendance data. The key consideration when assessing the scope to measure attendance is in determining whether it is a ticketed or non-ticketed event, as this strongly influences the approach required.

For ticketed events, organisers will have access to box office and ticket distribution data, although this may only provide an indication of sales and distribution. This may need to be cross-referenced with other sources that determine actual number of attendees, and which many organisers may already need to monitor linked to health and safety requirements.

For non-ticketed events, the approach is more complex and may require some primary research using a methodology to estimate crowd sizes. See below for further information.

Measuring Attendance at Ticketed Events

Attendance at ticketed events can be monitored by ticket sales, or tickets surrendered on entrance to gain admission. Where technology permits, other measures such as the total number of clicks on turnstiles can also be used as there can be no guarantee that all of those people who purchase a ticket for an event actually use them. The purpose of analysis is first to estimate the total number of attendances at an event, and then to down-weight it to the number of unique attendees by using a repeat viewing factor. We restate the requirement to differentiate between attendees and attendance, which applies not only to non-ticketed events but also ticketed events.

For some types of monitoring and evaluation (such as economic impact assessment) it may be necessary to distinguish between those whose attendance at the event is their primary motivation for being in the local area and those who are 'casuals', that is, people who are in the locality for some other primary purpose and their attendance at the event is a secondary consideration. It is conventional practice to exclude casuals from calculations such as economic impact and carbon footprint estimates because the impacts made by such attendees cannot be attributed to the event.

Suggested considerations when measuring attendance at ticketed events

• Primary data source will be box office data, ticket sales and ticket distribution
• The number of tickets distributed or sold does not always equal the attendance at the event
• Ticket buyers may not be the people who use them (i.e. group bookings and one person not always representative of the group)
• Some of the larger ticketed events may operate a reuse policy whereby people who leave an event early would relinquish their tickets, to be sold on to other spectators wanting to watch the action.

Ticket sales and distribution may provide a broad indication of the nature of the audience attending, however, primary research is required to provide more detailed information on those attending.

Measuring Attendance at Non-Ticketed Events

Having explained the importance of crowd sizes, it is perhaps worth explaining an 'open access' methodology in more detail. The approach has been developed as a result of the increasing number of open access events at which monitoring and evaluation work has been undertaken, particularly economic impact studies.

The methodology is based on crowd densities along the 2.5m crash barriers found on linear routes; the assumption being that these accommodate five people side by side. If barriers are on both sides of a 1km route and the crowd is one deep for its entirety then there would be 800 barriers (400 on each side of the road) and 4,000 spectators (5 x 800). Clearly this is the approach in simplistic terms, however, the final estimate is refined according to the experience of the research team at an event and with reference to their photographs and video footage at the event (and from event websites, blogs etc.). Moreover, where available, any recorded TV footage of the event plus aerial stills (where in some instances it is possible to count the people attending); is also used to derive crowd densities.

The 'no-stadium' methodology is particularly useful as a test of reasonableness for the estimates put out by event organisers. For example, if organisers claimed that an event attracted 100,000 spectators around a 1km course, it would be reasonable to expect crowd densities of around 25 deep on both sides of the road. If photographic and other evidence refute the expected crowd densities, then it is likely that crowd numbers have been overstated. In the case of large scale events, it is possible to derive a reasonably accurate estimate of attendance levels by surveying the community concerned after the event.

Some events report attendance figures on the basis of police estimates. We have interviewed two senior officers from the Metropolitan Police who have advised us that the police do not make any scientific estimates of crowd sizes and ideally do not like to have figures attributed to them. Any estimates attributable to the police are based on little more than hunches. Finally, any repeat viewing factor derived from primary research amongst spectators will be applied to derive an estimate of the number of different people en route. The 'open access' methodology can be adapted for crowds in open spaces such as free concerts based on the number of people per square metre.