Interactive Group Interviews

The most common form of in-depth interview in transport studies is the interactive group interview. These interviews usually take place in households where all members of the household take part in the interview. Jones (1985) provides an excellent comprehensive description of these techniques.

As noted by Jones, the interactive group surveys developed in transportation (of which Jones (1979a) and Brög and Erl (1980) are the best known) share three common features: interaction between participants, use of visual aids as a structuring device, and the development of gaming simulation techniques. With respect to interaction between participants, the interactive group survey is different, compared to a conventional structured personal interview travel survey, in that:

(a) interaction in the interview is exploited rather than suppressed;

(b) interviews are tape recorded, rather than recorded in written form during the interview, because the interviewer would not have enough time to conduct the interview and record the responses;

(c) interviewers are highly skilled and require a detailed understanding of the problem being studied;

(d) there is no formal questionnaire, although the interviewer may refer to a topic list during the interview;

(e) questions are framed during the course of the interview, in response to previous discussion; and

(f) probes and supplementary questions do not need to be phrased neutrally, as they would be in a structured interview; in some circumstances, the interviewer may act as a "devil's advocate" in order to elicit more detailed responses from the respondents.

Visual aids have an important role in a successful interactive survey methodology by introducing some element of structure into the discussion. In particular they may provide

- an aid to comprehension; - a (passive) prompt; - an aide memoir;

- a check on the feasibility of responses; - a means of dealing with complex issues; - a device for obtaining quantifiable data; and

- a means of contributing to a more relaxed interview environment.

As an example of the use of visual aids in an interactive survey, consider the interactive survey described by Jones (1979a, 1980) as the Household Activity- Travel Simulator (HATS). This technique employs the use of a display board, known as a HATS-board, as a central focus for the interactive survey (see Figure 3.2). Travel or activity diaries which have been completed by members of the household for a specified period before the interview are translated into a physical representation of a given day by means of coloured blocks along three parallel axes to indicate at-home activities, away-from-home activities and connecting travel activities. The spatial arrangement of these activities and trips is also shown on the HATS-board map. Household members are then given the chance to describe their activity-boards and to discuss possible interactions between the activity-boards of several members of the household. The HATS- board provides the focus for these discussions, by fulfilling the functions listed above.

The third element of interactive surveys is the use of a gaming simulation approach within the interview. The use of these "what-if" techniques enables the analyst to investigate the range of likely adaptations to a variety of policy options. For example, in the HATS survey, after the group members have finished discussing their current travel and activity patterns, they are asked to respond to various changes in policies which may affect either their activity or travel patterns. The responses are shown by rearrangement of the blocks on the HATS-board and/or rearrangement of the spatial patterns on the map. Problems which arise as a result of these responses immediately become visible on the activity-boards and map, in terms of gaps between blocks, overlapping blocks, no travel block linking at-home and away-from-home activities, and inconsistencies between activity-boards for various members of the household.

7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 NON- HOME ACTIVITIES HOME ACTIVITIES TRAVEL

TIME OF DAY ACTIVITIES REPRESENTED BY COLOUR-CODED BLOCKS MAP OF AREA WITH

COLOURED MARKERS TO SHOW LOCATION OF ACTIVITIES

Figure 3.2 A Completed HATS Display Board

(Source: Jones, 1985)

These inconsistencies result in individual adaptations being tested by one member of the household and then re-checked with other members' adaptations. In Monopoly-game fashion, the members of the household engage in conversation and trade-offs to find feasible household adaptations to the policy changes. In the process, numerous infeasible adaptations are suggested and

rejected. After a final adaptation is adopted by all members of the group, the HATS-board displays are coded onto new activity diaries and these, together with a tape recording of the discussion, form the basis for future analysis.

The HATS technique can be most effectively used to investigate the adaptation to forced changes (e.g. curtailment of a public transport route), but may also be used to investigate the effects of a permissive change (e.g. providing a new activity at an away-from-home location) which allows, but does not necessitate, a change to be made. In the later case, greater attention needs to be paid to the feasibility of any suggested adaptations.

The HATS technique, or variations of it, has been used in a variety of situations including the assessment of the attitudes of bus driver's towards a variety of patterns of shift work (Bottom and Jones, 1982), the reactions of households to various policy measures aimed at reducing transportation energy consumption (Phifer et al., 1980), the identification of transportation needs of disabled people (Faulkner, 1982), and possible reactions to congestion management strategies (Ampt and Jones, 1992).

A slightly different approach to the use of simulation in interactive surveys has been adopted by Brög and Erl (1980). In their methods, they adopt the concept of the "situational approach" which assumes that an individual's travel patterns are not simply a function of that individual's preferences, but also depend on the social and environmental situation in which that individual exists. Once again, they use the idea of an in-depth survey in which an interactive "what-if" simulation is employed, but they present the results of the simulation in terms of a hierarchical decision-tree which illustrates the effects of situational constraints on that individual. An example of such a decision-tree is given in Figure 3.3, which demonstrates the potential for usage of a new transit route in Melbourne, Australia (Ampt et al., 1985). It can be seen that although a large proportion of the population under study had the new mode objectively available to them (25% in Reservoir and 75% in Kingsbury), most of these potential users were subsequently eliminated from consideration by a variety of situational and perceptual filters. This method of presenting the results of an interactive group survey have been found to be highly effective in explaining the results of such a survey to a non-technical client. The method has been used in a range of applications, including studies of the potential of bicycle travel (Brög and Otto, 1981), long distance personal travel (Brög, 1982), and urban public transport (Brög and Erl, 1981).

Objective Option Constraints Information Time Cost Comfort Subjective Willingness

Final Potential Market

Suburb of Reservoir Suburb of Kingsbury

100

73.8

26.2

12.8

11.8

0.7

11.1

0.0

11.1

2.3

8.8

0.3

8.5

100

24.6

75.4

38.2

23.6

5.6

18.0

0.0

18.0

6.2

11.8

3.0

1.6

24.6

13.6

61.8

8.8

No

Yes

No

Yes

Y

N

Y

N

Y

N

N

Y

N

Y

N

Y

N

Y

N

Y

N

Y

N

Y

N

Y

N

Y

Figure 3.3 Decision Trees in the Situational Approach Survey

While interactive survey techniques have been found to possess a number of distinct advantages when attempting to understand travel behaviour, they do have a number of limitations, including:

(a) The interactive survey method is expensive. The cost per interview may be three to four times more expensive than a structured personal interview survey;

(b) Interactive surveys must be carried out by experienced interviewers who have a good knowledge of the subject matter of the survey. Often it is the researcher or principal investigator who must conduct the interview. This is necessary because only a person in this position will have enough detailed understanding of the topic to be able to follow up avenues of thought which arise spontaneously in the interview and which appear to be most productive. Thus, as well as being costly, interactive surveys, because of their limited manpower base, can also be very time consuming;

(c) Because of their time and cost requirements it follows that, within a limited budget, only a relatively small number of interactive surveys may be completed for any one study. This may pose problems when attempting to make generalisations from such a small sample; and

(d) Interactive surveys do not yet provide data in a form that is amenable to the construction of detailed mathematical models of travel behaviour or traffic flows. While progress has been made in this direction (e.g. the CARLA simulation model developed at Oxford University (Clarke, 1984)), the end-product of interactive surveys is not the production of seemingly precise estimates of traffic flows or transit patronage. Rather, they seek to provide a better basic understanding of travel behaviour. On the other hand, there are many advantages to these methods. Although there are some cases where interactive methods may form the main approach to studying a transport problem or issues, most of the application of this method lies in using it in the context of a more conventional, quantitative travel study. Jones (1985) suggests that there are three broad roles which interactive techniques can perform in this context, as shown in Figure 3.4.

The first of these is exploratory. Before the main study is begun, interactive measurement can be used as an aid to define transport problems and/or policy issues, and to help formulate the appropriate quantitative methodology. This can include content and wording of the questionnaires, the hypothesis formation or the provision of guidelines for appropriate modelling structure. This is probably the best developed and most frequently used role of the interactive interview.

Figure 3.4 The Roles of Interactive Interviews

(Source: Jones, 1985)

The second role for interactive surveys is investigative. Once a conventional travel survey has been completed, the analysis may raise a number of issues which cannot be answered by the data in a statistical way. This occurs often when the survey concentrated on what was happening in the study area, not why it happened - as is frequently the case in travel surveys. Interactive interviews can be employed in these situations to exploring certain issues in greater depth with respondents, or as a means of communicating findings and their implications to decision makers.

Finally, interactive surveys may be used as investigative tools. Rather than being

confined to a role in preparation or conclusion of a survey, they may actually be used as a component of the main study phase (e.g. Ampt and Jones, 1992), as one means of investigating the subject matter. This is often achieved by using in- depth interviews or group discussions alongside structured surveys as a complementary means of obtaining information about behaviour. In some cases the association may be even close, with interactive methods being used to inform model development through the use of gaming simulation to guide model inputs, structures and forecasts (e.g. Brög and Zumkeller, 1983).

3.3 SUMMARY OF SURVEY METHOD SELECTION

The final choice of survey method will depend upon a matching of the characteristics of the individual survey methods, as outlined above, with the objectives of the survey. This will be tempered by the resources available for the conduct of the survey. Stopher and Banister (1985) summarise the issues to be faced in the selection of a survey method and Table 3.2 builds on this to include the survey types discussed in this chapter.

Table 3.2 Uses of Each Survey Method

Data Type

Survey Type Factual Travel _DemographicsFactual Attitudes, Opinions

Documentary searches Yes Yes Yes

Observational surveys Yes No No

Household self-

completion Yes Yes Limited

Telephone surveys Household Individual Validation No Yes Yes Yes Yes Yes Limited Limited Yes

Intercept surveys Limited Yes No

Household personal

interview Yes Yes Yes

Group surveys Limited Limited Yes

In-depth surveys Limited Limited Yes

In line with the "Total Design" concept proposed by Dillman (1978), several authors have suggested the need for a dual or multiple survey mechanisms for the collection of data. In such a process, a battery of survey methods would be used to collect data, with each method being used in its most appropriate context. For example, as noted earlier, Sheskin and Stopher (1980) used a combined on- board questionnaire survey and a take-home questionnaire survey for gathering data on public transport users. Stopher (1985a) suggests the combination of personal interviews with mail-back questionnaire surveys, and telephone surveys with mail-out/mail-back surveys (Stopher, 1982). Shaw and Richardson (1987) report on the combination of an activity centre interview with a mail-back questionnaire survey. Brög and Erl (1980) point to the need to use a variety of methods within an overall study design and offer the following general guidelines:

(a) Structured questionnaires are appropriate for obtaining socio- demographic data at a person and household level;

(b) Diaries are the best means of obtaining activity and travel

information (otherwise respondents tend to recall typical behaviour rather than provide an accurate record for the survey period); (c) Land-use and transport system information is best obtained from

(d) Face-to-face, in-depth unstructured interviews are appropriate for exploring perceptions and attitudes;

(e) Group discussions are a better means of obtaining information about household organisation, decision rules, etc. than direct questioning, since household members are often unaware of their own

organisational structures; and

(f) Simulation techniques are a useful means of exploring response to change, as they make explicit the constraints, options and decision rules which contribute to the observed adaptation.

In general, after reading this chapter, we think it becomes clear that the selection of the survey method can only sensibly take place after a careful period of preliminary planning to ensure that the survey method chosen is best suited to measuring what is needed to fulfil the study and survey objectives. Furthermore, we hope it also becomes clear that the selection of a survey method is vital to ensuring that the highest quality data is collected in the most cost effective way.

In document Survey Methods for Transport Planning (Page 75-84)