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Qualitative Research: Case Study Guidelines

The following guidelines are provided for submissions reporting case study research aimed at understanding a bounded phenomenon by examining in depth, and in a holistic manner, one or more particular instances of the phenomenon. Case study research in TESOL and second language acquisition (SLA) has its origins in psychology and linguistics (e.g., Hatch, 1978), with a focus on the development of L2 syntax, morphology, phonology, and so on, as analyzed by an ostensibly objective researcher. More recently, TESOL case studies have adopted the more subjective and interpretive stance typical of case studies in education and other fields (Gall, Borg, & Gall, 1996; Johnson, 1992; Stake, 1994, 1995), with less emphasis on the acquisition of discrete linguistic elements and more emphasis on such issues as learners' and teachers' identities, skill development and its consequences for learners, teachers' professional development experiences, and the implementation of language policies in programs and countries. Both approaches are legitimate but require sufficient detail and contextualization.


  1. In TESOL, a case typically refers to a person, either a learner or a teacher, or an entity, such as a school, a university, a classroom, or a program (see Faltis, 1997; Johnson, 1992; Nunan, 1992). In language policy research, the case may be a country. Case studies may be included in larger quantitative or qualitative studies to provide a concrete illustration of findings, or they may be conducted independently, either longitudinally or in a more limited temporal period. Unlike ethnographic research, case studies do not necessarily focus on cultural aspects of a group or its members. Case study research may feature single cases or multiple cases (e.g., often two to four).
  2. Acknowledging multiple realities in qualitative case studies, as is now commonly done, involves discerning the various perspectives of the researcher, the case/participant, and others, which may or may not converge (Yin, 1994). As an interpretive, inductive form of research, case studies explore the details and meanings of experience and do not usually attempt to test a priori hypotheses. Instead, the researcher attempts to identify important patterns and themes in the data. The richness of case studies is related to the amount of detail and contextualization that is possible when only one or a small number of focal cases and issues are analyzed. The writer's ability to provide a compelling and engaging profile of the case, with suitable examples and linkages to broader issues, is also very important.


Context. Provide sufficient contextual information about the case, including relevant biographical and social information (depending on the focus), such as ESL learning/teaching history, L1 background, years of residence in a new country, data collection site(s), or other relevant descriptive information pertaining to the case and situation.

Sampling. Purposeful sampling is generally used in case study research; therefore, explain sampling procedures and case selection, and the defining characteristics and typicality or atypicality of the case: Note whether the case in question is a deviant or extreme case, a critical case, a convenience case, a politically significant case, and so on (Creswell, 1998; Miles & Huberman, 1994). Because attrition may deeply affect longitudinal case studies based on just one or two participants, sampling carefully is crucial. If multiple cases are used, researchers often provide a detailed account of each and then some form of cross-case comparison, either in prose or in a tabular summary (Creswell, 1998). Multiple cases are often preferable to single cases, particularly when the cases may not be representative of the population from which they are drawn and when a range of behaviors/profiles, experiences, outcomes, or situations is desirable. However, including multiple cases limits the depth with which each case may be analyzed and also has implications for the structure and length of the final report.

Data. Draw data either from one primary source (e.g., oral interviews, journals, or essays) or from multiple sources. As in ethnography, bringing together (triangulating) multiple perspectives, methods, and sources of information (e.g., from interviews, observations, field notes, self-reports or think-aloud protocols, tests, transcripts, and other documents) adds texture, depth, and multiple insights to an analysis and can enhance the validity or credibility of the results. Observations and data collection settings may range from natural to artificial, with relatively unstructured to highly structured elicitation tasks and category systems, depending on the purpose of the study and the disciplinary traditions associated with it (Cohen & Manion, 1994). Data in SLA studies may be somewhat more restricted (either interviews, tests, writing samples, think-aloud protocols, or grammaticality judgments), and the analytic focus may be narrower and more technical as well, such as the development of linguistic or rhetorical structures in oral or written L2 production. Establishing a trusting relationship with research participants, using multiple elicitation tasks (data collection procedures), obtaining adequate relevant background information about case participants and sites, and having access to or contact with the case over a period of time are, in general, all highly desirable.

Analysis and Interpretation

Analysis. Case study data analysis generally involves an iterative, spiraling, or cyclical process that proceeds from more general to more specific observations (Creswell, 1998; Palys, 1997; Silverman, 2000). Data analysis may begin informally during interviews or observations and continue during transcription, when recurring themes, patterns, and categories become evident. Once written records are available, analysis involves the coding of data and the identification of salient points or structures. Having additional coders is highly desirable (but is less common in qualitative research than in quantitative research), especially in structural analyses of discourse, texts, syntactic structures, or interaction patterns involving high-inference categories leading ultimately to the quantification of types of items within categories. Data reduction may include quantification or other means of data aggregation and reduction, including the use of data matrices, tables, and figures (Miles & Huberman, 1994).

In multiple case studies, each case may represent a different thematic finding, such as a different type of learner, teacher, or program (e.g., highly successful vs. less successful, domestic vs. international), which you may also portray as a clustering of properties or even a metaphor; alternatively, you may analyze and discuss each of the cases in terms of a small number of pervasive and important themes that run across them to varying degrees.

Interpretation. Establishing the significance or importance of themes or findings is crucial; the discussion should ideally link these themes explicitly to larger theoretical and practical issues. However, generalization to populations is not appropriate or desirable in most case studies. Be cautious about drawing unwarranted inferences because of the small sample size, particularly if the case is not typical of others in the same set. L2 researchers frequently propose models or principles based on their results to be supported, tested, compared, or refuted by themselves or others in subsequent research (e.g., Schmidt, 1983; Schmidt & Frota, 1986).

Data may be analyzed and interpreted through a variety of ideological lenses (e.g., positivist, poststructuralist, feminist, or critical (Duff, 2002; Merriam, 1998; Yin, 1994), although descriptive/interpretive approaches are still the most common in TESOL. Provide sufficient evidence for your claims or interpretations to make them clear, credible, and convincing to others. Consider alternate explanations, and account for results that run contrary to the themes that emerge or for differences among triangulated sources. It may be worthwhile to consult case participants for their interpretation of (nontechnical) data or findings. Young L2 learners or others who are not highly proficient in their L2 may not have the maturity or the linguistic competence to convey their perspectives easily; in some cases, an assistant who can speak the participant's L1 to explain the research purposes and elicit the participant's views in their L1 may be helpful, depending on the focus of the study (Duff, in press).

The Case Study Report

Reports of case studies submitted to TESOL Quarterly should include the following elements:

  • a statement of the study's purpose and the theoretical context
  • the problem or issue being addressed
  • central research questions
  • a detailed description of the case(s) and explanation of decisions related to sampling and selection
  • context of the study and case history, where relevant
  • issues of access to the site/participants and the relationship between you and the research participant (case)
  • the duration of the study
  • evidence that you obtained informed consent, that the participants' identities and privacy are protected, and, ideally, that participants benefited in some way from taking part in the study
  • methods of data collection and analysis, either manual or computer-based data management and analysis (see Weitzman & Miles, 1995), or other equipment and procedures used
  • findings, which may take the form of major emergent themes, developmental stages, or an in-depth discussion of each case in relation to the research questions; and illustrative quotations or excerpts and sufficient amounts of other data to establish the validity and credibility of the analysis and interpretations
  • a discussion of factors that might have influenced the interpretation of data in undesired, unanticipated, or conflicting ways
  • a consideration of the connection between the case study and larger theoretical and practical issues in the field

References and Further Reading on Case Study Research

Cohen, L., & Manion, L. (1994). Research methods in education (4th ed.). London: Routledge.

Creswell, J. W. (1998). Qualitative inquiry and research design: Choosing among five traditions. Thousand Oaks, CA: Sage.

Duff, P. (2002). Research approaches in applied linguistics. In R. A. Kaplan (Ed.), The Oxford handbook of applied linguistics (pp. 13-23). Oxford: Oxford University Press.

Duff, P. (in press). Case study research in applied linguistics. Mahwah, NJ: Erlbaum.

Faltis, C. (1997). Case study methods in researching language and education. In N. Hornberger & D. Corson (Eds.), Research methods in language and education (pp. 145-152). Dordrecht, Netherlands: Kluwer.

Gall, M. D., Borg, W. R., & Gall, J. P. (1996). Educational research: An introduction (6th ed.). London: Longman.

Hatch, E. (Ed.). (1978). Second language acquisition: A book of readings. Rowley, MA: Newbury House.

Johnson, D. M. (1992). Approaches to research in second language learning. New York: Longman.

Merriam, S. B. (1998). Qualitative research and case study applications in education. San Francisco: Jossey-Bass.

Miles, M. B., & Huberman, A. M. (1994). Qualitative data analysis: A sourcebook of new methods (2nd ed.). Thousand Oaks, CA: Sage.

Nunan, D. (1992). Research methods in language learning. Cambridge: Cambridge University Press.

Palys, T. (1997). Research decisions: Quantitative and qualitative perspectives (2nd ed.). Toronto, Ontario, Canada: Harcourt Brace Jovanovich.

Schmidt, R. (1983). Interaction, acculturation and the acquisition of communicative competence: A case study of an adult. In N. Wolfson & E. Judd (Eds.), Sociolinguistics and second language acquisition (pp. 137-174). Rowley, MA: Newbury House.

Schmidt, R. W., & Frota, S. N. (1986). Developing basic conversational ability in a second language: A case study of an adult learner of Portuguese. In R. R. Day (Ed.), Talking to learn: Conversations in second language acquisition (pp. 237-322). Rowley, MA: Newbury House.

Silverman, D. (2000). Doing qualitative research: A practical handbook. Thousand Oaks, CA: Sage.

Stake, R. E. (1994). Identification of the case. In N. K. Denzin & Y. S. Lincoln (Eds.), Handbook of qualitative research (pp. 236-247). Thousand Oaks, CA: Sage.

Stake, R. E. (1995). The art of case study research. Thousand Oaks, CA: Sage.

Weitzman, E. A., & Miles, M. B. (1995). Computer programs for qualitative data analysis: A software sourcebook. Thousand Oaks, CA: Sage.

Yin, R. K. (1994). Case study research: Design and methods. Thousand Oaks, CA: Sage.

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