A1: Surveys for Behavioural Experiments Peter Jones, CTS, UCL Regine Gerike, TUD Giorgia Servente, Polito, TO

Workshop Context Many countries are considering using VBC programmes to influence (travel) behaviour How should such programmes be monitored and evaluated? Are there methodological problems unique to VBC? Are there best practice recommendations? What are the methodological research challenges?

Existing Travel and Consumption Patterns Voluntary Behaviour Change Intervention POST Travel and Consumption Patterns SURVEY DESIGN PROCESS ** Need for Change: Policy OBJECTIVES?

Existing Travel and Consumption Patterns Voluntary Behaviour Change Intervention POST Travel and Consumption Patterns What were the IMPACTS of the intervention? - On Subjects - On Others CONTROL Group SURVEY DESIGN PROCESS ** Need for Change: Policy OBJECTIVES?

Existing Travel and Consumption Patterns Voluntary Behaviour Change Intervention POST Travel and Consumption Patterns WHAT Led to the Observed Changes? = PROCESS What were the IMPACTS of the intervention? -On Subjects - On Others CONTROL Group SURVEY DESIGN PROCESS ** Need for Change: Policy OBJECTIVES?

Key Issues - 1 What are we trying to measure? –What are our objectives? (reduce car use, save energy, increase physical activity…) –What about secondary impacts? (local economy, traffic accidents…) –Are we seeking just to measure change or understand reasons for people to/not to change?

Key Issues - 2 Ways of measuring behaviour: –Take up of marketing information –Reported behaviour (trips, durations, etc) –Direct individual consumption measures (odometers, GPS, etc) – reported or relayed –Aggregate area measures (bus passengers, traffic, etc)

Key Issues - 3 How to identify ‘real’ change: –Need for ‘control’ groups – difficult! –Potential biases in reporting, especially with VBC programmes  Retrospective vs. pre-determined  Key importance of question framing  Greater risks where respondents associate survey with VBC programme –Dangers of using panel surveys

Key Issues - 4 How to assess statistical significance: –Systematic vs. random errors –What level of significance do we really need? –Large samples are expensive to collect  Possible scope for meta analysis? –Importance of % response rate:  Higher % => lower mean trip rate

Key Issues - 5 When should impacts be measured? –Allow time for effects to settle down (e.g. after expiry of free bus tickets) –Match ‘before’ and ‘after’ seasonally How long do impacts last? –May increase over time (snowball effect)..?

Key Issues - 6 How can we understand causes of changes and willingness to change? –Trips as multi-dimensional packages –Need to ground in psychological theory (e.g. Theory of Planned Behaviour) –Important role for qualitative research …..All of which can help inform best type of VBC interventions

Some Key Research Areas Accuracy/role of ‘meter’ readings How best to integrate data sources Defining effective control groups Cultural effects (survey and behaviour) Deeper understanding of change processes Importance of ‘interviewer’ effects? Greater use of experimentation (reduced need for precision in evaluating practical applications?) ‘Tool kit’ for VBS evaluation: low cost options for developing countries