The pros and the cons of the quantitative and qualitative approaches : when do we mix both? Two cases on modal choice DEST-INRETS Jean-Loup Madre Frédérique Prédali with the contribution of Anaïs Rocci COST Madrid - May 2007
OBJECTIVES • Advantages and Limitations of each approach: • exclusively quantitative • exclusively qualitative • Complementarity between these approaches • " We have to overpass the barrier between qualitative and quantitative methods… • … each of them has its own advantages, depending on the questions tackled" • Two exemples (PhD theses conducted at INRETS-DEST) • about Changing Behaviour for Modal Choice by the inhabitants of the Metropolitan Area of Paris • A sound distinction between : • Theoretical limitations • Usual Practice • e.g. the mean value does not sum up the whole distribution
EXCLUSIVELY QUANTITATIVE APPROACHES Jean-Loup MADRE Madrid – COST 355 May 2007
DIFFERENT DATA SOURCES • Administrative data (e.g. traffic counts) • Survey data • Optimising Sample Scheme and Confidence Interval calculation • Open or Closed questions • Different types of variables, depending on data accuracy: • Quantitative Variables (rounding) • Ordered Qualitative variable (for inaccurate measurement) • purely Qualitative variables (complex structures) • What dimensions of the question can be tackled through a quantitative approach ? • What kind of description is given (often too much simplified) ?
A case using exclusively the qualitative approach A study of Anaïs Rocci Madrid – COST 355 May 2007
Choice of methodology : Why qualitative is prefered? • The choice depends on the tackled questions : • Understand the modal choice and the hindrances to change mobility patterns: • Why most people are not prepared to refrain from using cars? • What are the limiting factors to a change and to an acceptability for more sustainable mobility practices? • The qualitative allows to understand : • the logics in daily life of each individual thanks to the experience described in the interviews • the deep motivations and how modal choice is progressively elaborated • the complexity of behavioural mechanisms : what discrepancies between actual behaviour and its description?
The sample and the method • 40 individuals living in Paris Region • Interviewed face to face lasting 2 hours with a semi-directive questionnaire • Chosen for the diversity of their modal habits : Exclusive with car, Alternative modes user, Multimodes users. And the diversity in the main types of trips : city to city, city to suburbs/suburbs to city, suburbs to suburbs. • The sample is not representative of the people living in Paris Region.The aim is to show: • A diversity of occurrences • Individuals’ complexity, logics and mechanism of action • Complementary insights to quantitative studies. • Some individuals were interviewed twice (or more) because they told they will sell their cars for example. • The repeated interviews allow to see the change or the difficulties of changing habits. • We can then analyze what is not possible to quantify.
Changing process Giving up the car :A move eventCyril, 27 years old. Banker. Main trip was suburb to suburb, now Paris to Paris Moving to the city makes him change his mind because of the image he had of the city where car is useless, and because of the constraining measures Living in the south of France, he moved to Paris suburbs Used to have a car from 18. Can’t imagine to move without a car His wife wanted to be closer to her work place Recently, move to Paris He finds a new job in Paris Changes: from the car use, to public transport and walk Work place at 10’ walking Keep using the old car to go to suburbs car seems to him useless in Paris Car too stressful and constraining Difficulties to sell the car Lost references and habits Has to try other modes Difficult for week end and holidays After selling it: difficulties to adapt himself to another way of moving
Results : criteria and strategies of car use • Justifications using the car for all trips and strategies adopted to avoid the obstacles: • Knowledge in mobility (capital of mobility): • car drivers do not often know how to use another mode but they know the shortest way or the best hours to avoid traffic jam… • Ready to accept some constraints, if they are compensated, controlled or known in advance (traffic jam, parking) • Selective memory : only the best is remembered, and constraints are forgotten. • Changing requires to learn and adapt itself to a new system of mobility, and to become familiar with a new practice, a new mode of transport. • All criteria are integrated in a global cost: • Social cost • Perception of the monetary cost, travel time and reliability • Gain in activities • Simplicity to get into the mode • Psychological cost • Feeling of control and power on one’s own mobility
The qualitative results • Show the importance of the modal experiences when people have to chose • Understand that the car users would not be ready to change their mobility patterns, not only because of car anchoring in mentalities and society, but also because : • they do not have other choices, other real alternatives or they do not know them. • People would not be sufficiently aware to environmental problems to make it a factor of change. • Drivers would be ready to change if they keep feeling control on their mobility.
A case which mixes both approaches Frédérique Prédali Madrid – COST 355 May 2007
How to explain the methodologic choice? • The subject of the study (PhD) : Understand the specificities and the evolution of middle-aged women’s mobility(in Paris Region) • The question deals with activity patterns and modal choice in daily life. It is a cross-disciplinaries field. • The Institute has the data of the household mobility surveys but is this sufficient to cover the subject ?
What do we do with qualitative approach? • The subject is sociologic, that means qualitative approach is needed : but do we begin the research with interviews or by exploring statistical way? • The qualitative approach was privileged to begin the research "by the experiences of life". We can then have an overview of women’s mobility patterns. • It’s also useful when we need to go further in the interpretation of the statistical results. So new statistical treatments can be done.
Determination of the qualitative sample • 20 women (from 25 to 49 years old) living in Paris Region • Found step by step (the first woman interviewed had identified another one to potentially interview, and so on) • Chosen for the diversity of situations : • Family environment • Professional environment • Modal choice (no car for ex.) • Residential area… • Interviewed (face to face during 1 hour at least) with a semi-directive questionnaire.
Building a typology • The interviews were analyzed by contrast (facing situations) : • Does the woman live with a partner or not? • Does she live with (a) child(ren) or not? • Is she working or not? If she works, is it a full or a part-time job ? • Living in the city of Paris/ in the surburbs / outskirts • Is the household motorized or not? Etc. • The qualitative way offers a tremendous amount of informations on the individuals but does not allow to generalize the results. • So the typology has been based on the quantitative sample.
Working on household mobility survey • The survey of Paris Region (EGT – 1992) has been exploited through the structure of the households : • woman living alone (“single”) • woman living with a man, without child (“couple”) • woman living with a man and minor children (“traditional family”) • woman living without man and with minor children (“single-parent family”) • In order to give travel measures (motorization, driving license, travel card, number of trips, purposes, average journey length…) • Then, new ideas of treatments were drawn thanks to the analysis of qualitative survey : • The schedules of trips • The time use (daily average) : at home, for tripsand other activities outside home such as work, shopping
Results on the modal choice :Incidence of family structure on the public transport use • Women which are working and living with a working partner have more often a travel card than men. But the most significant differences are between the types of households (EGT). • The « single » women feel the trips in public transport as self-centered moments whereas mothers feel tired and wasting time. The PT consumers have a good perception of their mode, faster and more reliable than car (qualitative survey). Women are greater consumers of public transport than men, even for the home-to-work trips. Possession rate of monthly travel card among the working population sample Field : women (25-49 years old) and their partners Source : EGT 92
Results on the modal choice :Incidence of family structure on the motorization • The car is an essential tool for mothers, in particular when the children are in low-aged. Mothers feel safier with a car close to their home. Even low-income families want a car for these reasons (qualitative survey). • Having a partner and a job are two others reasons explaining the level of motorization (EGT). The level of households’ motorization increases with the presence of child(ren) Level of motorization of the double-waged households Field : women (25-49 years old) and their partners Source : EGT 92
The car use does not only depend on the driving license and the access to a car : some of the interviewed women told they do not like to drive. As they do not drive, their partners have to drop them and the children every day. Incidence of family structure on the car use Distance driven by car (in km) Field : Man and woman of 25-49 years old, having driving license Source : EGT 92
About mixed methodology • A qualitative approach requires a long time of analysis: • Each individual is unique • No figures, no means • No help from any software to cross the informations • This kind of topic is analized through gender studies (mainly in the USA) with a quantitative approach. We could go deeper in the analysis with a mixed methodology.
Conclusions • A mixed approach: • For exploring a new field, a qualitative survey for elaborating hypothesis and questionnaire • Quantification of findings for generalizing them • Qualitative phasis afterwards for illustrating the results and a deeper analysis • Overpassing the quali/quanti barrier : • Two valid points of view on the same behaviourial changes. • Avoid misinterpretations from the surveyor or the analyst • No generalizable figures can be derived from Quali, • But results can be checked (real and not unique situations) • Building a typology is difficult from a wide variety of individual situations • Not enough for policy making because not representative at macro level