Empleo en zonas con peligro de explosión

Different validity criteria have been proposed by different authors in the field of qualitative research methods including ethnography. Some criteria reflect the influence of the post positivist research perspective (e.g., Lincoln & Guba, 1985; Morrow, 2005), while other criteria, consisting of notions such as creativity, reflexivity, and congruence (Marshall, 1990; Popay et al., 1998) indicate a de- parture from this framework, aligning with interpretive perspectives. There is a variation also in how individual researchers select or develop validity criteria in specific research projects (Henry, 2015). Due to a lack of commonly shared criteria for ensuring validity of qualitative research projects, Henry (2005) and Maxwell (1996) argue that researchers should have discretion to creatively select and/or develop criteria consistent with the purpose of a specific research project and circumstances in which the project is conducted. In keeping with this argu- ment, the criteria considered suitable for this study were: credibility, transfera- bility, reflexivity, sensitivity, creativity, thoroughness, and congruence (Henry, 2015; Lincoln & Guba, 1985, 1994; Marshall, 1990; Maxwell, 1996; Popay et al., 1998).

Credibility is the extent to which the research findings reliably reflect the re- search participants’ experiences, meanings, and social context (Lincoln & Guba, 1994; Maxwell, 1996). In the present study, credibility was enhanced by pro- longing the fieldwork period to one year to allow an in-depth study and under- standing of the research participants, their mathematics learning context, ma- thematical identities and experiences. Different kinds of data (i.e., in the form of students’ narratives, observation field notes, official documents, and question- naire-based data) collected and analyzed during the fieldwork, aimed at ensuring consistence between research findings and students’ experiences, meanings, and the mathematics learning context. In addition, the notebook-based correspon- dence between the researcher and students allowed the researcher to ask addi- tional questions to let the students clarify what they had previously written.

Transferability, which refers to the applicability of the research findings to other contexts with similar characteristics (Lincoln & Guba, 1985), was en- hanced by presenting a thick description of the context in which the students learned mathematics, their mathematical identities and experiences, and by clearly describing the patterns defining the variation of mathematical identity and experiencing across the participants. These patterns were accurately de- scribed with a view to increasing the likelihood of their applicability to other mathematics learning contexts in Tanzania.

Reflexivity, a conscious process of self-criticism, can help researchers mi- nimize the influence of their preconceptions or bias that may reduce the validity of the research process and outcome (Maxwell, 1996; Patton, 1990). In this study, self-criticism of stereotypical thoughts and seeking context-based evi-

dence to prove or disprove pre-conceived ideas constituted strategies for mini- mizing the influence of these ideas especially in the beginning of the fieldwork. In addition, sensitivity refers to the researcher’s consciousness and considerate- ness of research participants’ views, culture, and context (Marshall, 1990). Based on this criterion, I built a rapport with students in the beginning of the fieldwork using a shared language (Swahili) to easily understand students’ con- cerns and feelings during the research process. Moreover, consistent with the local cultural expectations, I acknowledged the students’ help by thanking them and presenting each student with a notebook and a pen.

Creativity, another validity criterion, requires researchers to adapt and use methods, ideas, and principles appropriate to the circumstances of a specific research project to help them achieve their research goals without undermining the principles of scientific inquiry (Patton, 1990). In the present study, creativity was instrumental particularly during the fieldwork. For example, creativity was employed when determining a data collection method (the diary method) based on students’ preference and adapting it to the school’s tradition in which teach- ers communicated with students by writing in students’ notebooks. The other example of creativity was the development of a conceptual framework grounded in data for use in the interpretation of students’ narratives.

The thoroughness validity criterion generally refers to the attentiveness to de- tail and accuracy in the selection of research participants, data collection, and analysis (Morrow, 2005; Propay et al., 1998). Consistent with this criterion, the number of research participants was considered adequate because the data given by the participants addressed fully the purpose of the research, which was to describe and explain the characteristics and development of students’ mathemat- ical identity. Also, data collection and analysis proceeded together, employing methods relevant to interpretive ethnography.

Finally, congruence is a rather complex validity criterion. On the one hand, it refers to the harmonious relationship between research purpose, design, ques- tions, methods, procedures, and findings, but on the other, it refers to the relev- ance of research results to previous research findings and practice (Marshall, 1990; Morse & Richards, 2002). After establishing the purpose of research through preliminary data collection and analysis, congruence in this study was enhanced by developing a research design (interpretive ethnography), formulat- ing research questions, and selecting research methods and procedures, consis- tent with the research purpose. Congruence was also enhanced by evaluating the findings against the research purpose to ensure there was consistence between them. Moreover, this study extends the previous research scope by focusing on a classroom in which students varied greatly in their mathematical backgrounds (see Chapter 7). Also, since the study was grounded in data, it has evidence- based practical implications. For example, it stresses the use of pedagogical me-

These identity criteria—credibility, transferability, reflexivity, sensitivity, crea- tivity, thoroughness, and congruence—constituted an important basis for en- hancing the validity of the study. An evaluation of the trustworthiness of some of these criteria is detailed in section 7.5.1 of this dissertation.