社会科学“案例研究”究竟需要多少个“案例”？(英文).pdf

http:/ http:/ online version of this article can be found at:DOI:10.1177/1466138108099586 2009 10:5EthnographyMario Luis Smallfield-based researchHow many cases do I need?:On science and the logic of case selection in Published by:http:/ can be found at:EthnographyAdditional services and information for http:/ Alerts:http:/ University of Missouri-Columbia on January 16,Downloaded from How many cases do I need?On science and the logic of case selection infield-based researchMario Luis SmallUniversity of Chicago,USAA B S T R A C TToday,ethnographers and qualitative researchers infields such as urban poverty,immigration,and social inequality face anenvironment in which their work will be read,cited,and assessed bydemographers,quantitative sociologists,and even economists.They alsoface a demand for case studies of poor,minority,or immigrant groups andneighborhoods that not only generate theory but also somehow speak toempirical conditions in other cases(not observed).Many have respondedby incorporating elements of quantitative methods into their designs,suchas selecting respondents at random for small,in-depth interview projectsor identifying representative neighborhoods for ethnographic casestudies,aiming to increase generalizability.This article assesses thesestrategies and argues that they fall short of their objectives.Recognizingthe importance of the predicament underlying the strategies todetermine how case studies can speak empirically to other cases itpresents two alternatives to current practices,and calls for greater clarityin the logic of design when producing ethnographic research in a multi-method intellectual environment.K E Y W O R D Sethnographic methods,generalizability,representativeness,validity,case study,sequential interviewing,extendedcase method,sciencegraphyCopyright The Author(s),2009.Reprints and permissions:http:/www.sagepub.co.uk/journalsPermissions.navhttp:/ Vol 10(1):538DOI:10.1177/1466138108099586A R T I C L E005-038 099586 Small(D):156x234mm 11/02/2009 14:16 Page 5 at University of Missouri-Columbia on January 16,Downloaded from Probably the most memorable of the lectures of Nobel-prize winning physi-cist Richard Feynman was his 1974 commencement address at Caltech,where he described what he calls cargo cult science.Feynman,worriedabout the preponderance of what he believes are pseudo-sciences,comparesthese practices to the cargo cults of the South Pacific:In the South Seas there is a Cargo Cult of people.During the war they sawairplanes land with lots of good materials,and they want the same thing tohappen now.So theyve arranged to make things like runways,to put firesalong the sides of the runways,to make a wooden hut for a man to sit in.the controller and they wait for the airplanes to land.Theyre doing every-thing right.The form is perfect.It looks exactly the way it looked before.But it doesnt work.No airplanes land.So I call these things Cargo CultScience,because they follow all the apparent precepts and forms of scien-tific investigation,but theyre missing something essential,because the planesdont land.(Feynman,1999:2089)Feynmans lecture was devoted largely to practices such as ESP,but the hintsabout social science were difficult to miss.(In fact,he criticized a psychol-ogists advice to his student not to replicate the studies of others.)Pseudo-scientists were expert imitators but terrible practitioners,adopting the formof science but nothing else.In this respect,his analogy might have beenstronger had he noted that some New Guinean cargo cultists had fashionedtheir own airplanes out of logs,sticks,and leaves,remarkably accuratereplicas that,lacking engines and a foundation in aerodynamics,wouldnever fly(Harris,1974;Worsley,1968).While Feynman probably underestimated the successes of social science,his observations are worth noting by at least one major segment of contem-porary ethnographers,for whom the temptations of imitation have neverbeen stronger.The problem of imitation is not new to social scientists,whofrom the start have argued heatedly(and repeatedly)over the merits ofemulating the natural sciences in pursuit of social scientific methods(Dilthey,1988;Lieberson and Lynn,2002;Saiedi,1993).But today,animportant subset of ethnographic researchers and of qualitativeresearchers more generally faces its own version of that dilemma:whetherto emulate basic principles in quantitative social sciences in establishingstandards of evidence for qualitative work.Some background is necessary.1The predicament of ethnographic work in multi-method contextsThe predicament arises from what might seem to be an unqualified accom-plishment,the simmering of the counterproductive debates,which reacheda boiling point during the 1980s,over the relative merits of quantitativeEthnography 10(1)6005-038 099586 Small(D):156x234mm 11/02/2009 14:16 Page 6 at University of Missouri-Columbia on January 16,Downloaded from versus qualitative research.Todays calmer waters have been especiallyregenerative for the fields of urban poverty,social inequality,and immi-gration,where both quantitative and qualitative works flourish,and whereexperts in one methodological tradition frequently cite those in others.Infact,several major studies in these fields have employed,with varyingdegrees of integration,both quantitative and qualitative data,the latterbeing at times interview-based and at times ethnographic.Examples arePortes and Rumbauts recent studies of the children of US immigrants(Portes and Rumbaut,2001;Rumbaut and Portes,2001),Wilson and hiscolleagues studies of urban conditions in Chicago(Wilson,1996;Wilsonet al.,1987),and England and Edin and their colleagues studies of urbansingle mothers in the US(see England and Edin,2007).These fields standin contrast to others where,for epistemological,political,or historicalreasons,most practitioners work within a single method or set of methods,as in symbolic interactionism or the interpretive work on culture.But the more cooperative spirit in urban poverty,social inequality,andimmigration has only spread so far.Despite the more methodologically openenvironment,research in these fields remains dominated by quantitativesociologists,demographers,and even economists(Wacquant,1997;see alsoBurawoy,2005).While important ethnographies in these fields continue tobe published and highly cited(e.g.Duneier,1999;Levitt,2001;Pattillo,1999;see Newman and Massengill,2006),most articles in these fieldspublished in the top generalist journals,such as American Journal of Sociology,the American Sociological Review,and Social Forces,remainquantitative in nature.2The preponderance of statistical research stems inpart from the steady and continuous supply of easily accessible quantita-tive data,such as the decennial US Census,the Current Population Survey,the Panel Study of Income Dynamics,and the National Longitudinal Surveyof Youth,all of which contain many variables related to poverty,immi-gration,urban conditions,neighborhoods,and socio-economic status.Inaddition,urban poverty,social inequality,and immigration(along withcriminology,education,and public health)remain among the most highlyfunded fields in US social science,and the largest funders in these fields nonprofit organizations and government agencies such as the Russell SageFoundation,the Ford Foundation,the National Science Foundation,the USDepartment of Housing and Urban Development,and the National Insti-tutes of Health have exhibited a greater inclination to fund quantitativeprojects.The edited volumes generated by these funding streams bearevidence to this claim.Consider a few highly cited collections:Goering andFeins(2003)recent volume on the effects of neighborhood poverty,fundedby HUD;Neckermans(2004)volume on social inequality,funded byRussell Sage;and OConnor et al.s(2001)study of urban inequality inmultiple cities,funded by both Russell Sage and the Ford Foundation.EachSmallCase selection in field-based research7005-038 099586 Small(D):156x234mm 11/02/2009 14:16 Page 7 at University of Missouri-Columbia on January 16,Downloaded from of these volumes,while demonstrating deference to ethnographic research,overwhelmingly reports quantitative findings.3These circumstances have produced at least two consequences.First,incontrast to other fields where ethnographers work,ethnographic studies inurban poverty,inequality,and immigration are often evaluated evenon methodological grounds by quantitative researchers.Thus,whileethnographers doing work on,for example,narrative and culture can confi-dently expect their work to be reviewed primarily,if not exclusively,byother qualitative researchers,those in the aforementioned fields must countamong the potential reviewers of their work,demographers,quantitativesociologists,and even economists scholars who are experts on the subjectmatter without necessarily being experts on the method.Inevitably,thereviews will cover issues not traditionally addressed in closed ethnographicintellectual communities.For example,my Villa Victoria,an ethnographicstudy of a predominantly Puerto Rican housing complex in Boston,wasreviewed in Contemporary Sociology by a demographer,who,in a gener-ally balanced article,covered both theoretical and methodological issues.Yet the methodological discussion did not center on the extent to which Iattained an empathetic understanding of my informants,on the level ofreflexivity in the work,or on the extent to which the history of the neigh-borhood informed the analysis;instead,it focused on one of demographyscentral concerns,whether the neighborhood was representative:While the conditional approach is an asset from a theoretical stand point,itis a limitation from a methodological perspective.The generalizability of thefindings is a concern.Since theories are based on generalizations,focusingon exceptions as advocated by the conditional approach makes us questionthe applicability of these findings to other neighborhoods.(Morales,2006:284)Consider another example.Fordham and Ogbus(1986)highly cited studyof acting white among black students in a Washington,DC middle schoolhas been rediscovered over the last 10 years by sociologists and economistsinterested in culture and urban inequality,a rediscovery oriented towardmethodological and empirical issues.But this attention centered on none ofthe core issues identified in Burawoys(2003)recent review of types ofethnographic revisits,such as reconstructing the theory after returning tothe school or assessing the structural forces at play in US cities during thelate 1980s.Instead,the new critiques focused on whether the few dozenstudents interviewed by Fordham and Ogbu were statistically representa-tive of black students in US society(Ainsworth-Darnell and Downey,1998;Cook and Ludwig,1997).Consider a third example,from the literatureon transnationalism,where ethnographies,such as Levitts(2001)studyamong Domincan migrants to the US,have confirmed the prevalence ofEthnography 10(1)8005-038 099586 Small(D):156x234mm 11/02/2009 14:16 Page 8 at University of Missouri-Columbia on January 16,Downloaded from transnational practices among immigrants in all continents.In an import-ant recent study evaluating these works,quantitative researchers critiquedthe latter on methodological terms but not by focusing on the authorsability to conduct multi-site ethnography,or on the challenges of establish-ing rapport quickly and effectively in different countries.Instead,thecritiques focused on the questions that worry demographers,even employ-ing explicitly the language of variable selection:This emerging literature on immigrant transnationalism is characterized byan empirical base consisting exclusively of case studies.Qualitative casestudies consistently sample on the dependent variable,that is,they documentin detail the characteristics of immigrants involved in transnational activi-ties but say little about those who are not.(Portes et al.,2002:279;italicsadded)We may set aside for the moment whether any of these critiques is valid inorder to highlight the larger predicament:ethnographers in these fields canexpect to be assessed on their methods by quantitative researchers.Second,ethnographic studies in urban poverty,social inequality,andimmigration operate in an environment at once thirsty for in-depth casestudies that describe conditions in poor,minority,immigrant,or otherwisenon-mainstream groups,neighborhoods and communities,and either skep-tical or uncertain about the relationship between these small-n studies andthe larger population of groups,neighborhoods,and communities that thecase studies are expected to represent(Lieberson,1991).Consider acontrast.When Geertz(1973)wrote on the cockfights in a small Balinesevillage,many expected his theoretical model(of how games can embodysocietal power relations)to be applicable to other sites,but few expectedthe empirical findings to be so applicable that is,for cockfights to looksimilar or to follow the same rules in other villages throughout or outsideof Indonesia.The latter would be wholly beside the point.4But ethnogra-phers in the aforementioned fields work in a professional,intellectual,andpolicy environment that demands empirical findings applicable to othercases.When ethnographers today describe conditions in,for example,onepoor black neighborhood in St Louis,MO,many of their readers in theurban poverty literature expect to be learning about the conditions in poorblack neighborhoods in general in Boston,Los Angeles,New York,andperhaps even London and Rio de Janeiro not merely that neighborhoodin St Louis.In fact,ethnographies of single neighborhoods are often citedto argue that conditions in the ghetto,the underclass,the immigrantenclave,or other similar categories exhibit some set of empirical charac-teristics,such as desolation,graffiti,street disorder,gang presence,streetentrepreneurship,etc.(on the perils of this practice,see Small,2007,forth-coming b).Similar expectations surround the interpretation of in-depthSmallCase selection in field-based research9005-038 099586 Small(D):156x234mm 11/02/2009 14:16 Page 9 at University of Missouri-Columbia on January 16,Downloaded from interview studies with small numbers of respondents.When interpreting astudy of,for example,40 immigrant low-income women in San Diego,CA,researchers expect to learn something empirical about the conditions oflow-income immigrants in other cities and regions,not merely about those40 women.In sum,in fields such as urban poverty and immigration in theUS,ethnographic case studies are often explicitly expected to representlarger entities.Nevertheless and this is key the precise relationshipbetween such cases and the larger populations they are expected to represent remains unclear.It is in this context that imitation,as described earlier,arises.The corepredicament that many ethnographers face is deceptively straightforward:how to produce ethnographic work that keeps at bay the critiques expectedfrom quantitativ