Análisis detallado de los artefactos existentes en el mercado

A pilot study was conducted before the final implementation of the questionnaire in order to ensure the effectiveness and clarity of the questions and the validity of research instrument (Bryman, 2008; van Teijlingen & Hundley, 2001). The pilot study was also conducted to discover any weaknesses in the research design, and to assess the appropriateness and ease of use of the proposed research instruments or data collection methods (van Teijlingen & Hundley, 2001). Pre-testing the research instrument helps increase the success of the study, although there is no guarantee that successfully completing a pilot study will result in success of the full-scale survey (van Teijlingen & Hundley, 2001). Thus, a pilot study creates an opportunity to enhance the validity and reliability of the research.

3.3.5.1 Pretesting of the questionnaire

Initially, the first draft of the questionnaire was tested with 21 migrants who were recruited from the Migrant Resource Centres, ethnic associations and by snowball sampling. The recruitment started with a few migrants who had agreed to distribute the information sheet and to explain the project background and survey process to their network of migrants. The participants that were first approached were from the researcher’s own social network. As a result, 21 participants were recruited in the pilot study.

3.3.5.2 Validity

“Validity refers to when a test is measuring what is intended to be measured” (Matthews & Kostelis, 2011, p. 184). Simply, validity is the match between the construct and the measurement; whether the results of the measurement process are accurate (Huck, 2012). A research instrument is valid if it measures what it means to measure. In quantitative research, measurement validity is concerned with how well the research instrument fits with the construct that is being measured (Neuman, 2011a). In the social sciences, two approaches appear to establish the validity of a research instrument: logic and statistical evidence (Kumar, 2011). As stated by Kumar (2005),

Establishing validity through logic implies justification of each question in relation to the objectives of the study, whereas the statistical procedures provide hard evidence by way of calculating the coefficient of correlations between the questions and the outcome variables. Establishing a logical link between the questions and the objectives is both simple and difficult. It is simple in the sense that you may find it easy to see a link for yourself, and difficult because your justification may lack the backing of experts and the statistical evidence to convince others. (p. 154)

Hence, establishing a logical link between questions and objectives is easier when the questions relate to tangible matters. In this study validity issues were addressed through the care taken to construct the quantitative research instrument (the questionnaire), and by data checking through validation strategies such as member

checking and consultation with an experienced researcher. In this study, content validity of the research was reached.

Content validation was applied to “determine the appropriateness of categories or factors and the completeness of the corresponding questionnaire items to the categories or factors in the cognitive or affective domains” (Matthews & Kostelis, 2011, p. 186). Research can be said to have content validity if it covers all possible dimensions of the research topic (Sarantakos, 2013). Content validation of the questionnaire was carried out with three experts in this field of research and 21 migrants.

In the pilot study, the questionnaires were attached with feedback forms so that the participants could provide their suggestions on the content of the questions and their own personal experiences for the final version of the questionnaire. Through the feedback and comments from participants, and then discussion with supervisors and experts, the draft questionnaire was revised and improved before final

implementation (Teddlie & Tashakkon, 2009). The conclusion was that the content of the questionnaire covered the research interests that the study intended to examine. However, some amendments and corrections were needed. The details of the adjustments made in the questionnaire are discussed as below.

Some questions needed to be re-worded and arranged in a more logical sequence. For example, question 44 which asked about how migrants obtain food ingredients that they cannot buy from shops, was adjusted to make it clearer and more concise; while question 43 ‘Do you have other alternatives to get food ingredients you cannot buy from local food outlets or supermarkets?’ was removed to avoid repetition with question 44. One participant suggested that a wider range of options should be provided in question 12 which asked about income. There was also one request to provide examples for the option given in question 20 in order to make the option clearer.

3.3.5.3 Reliability

The concept of reliability is related to consistency or dependability. Four factors affect the reliability of an instrument: the wording of questions, the physical setting,

the participant’s mood and the regression effect of the instrument (Kumar, 2011). Clear conceptualising constructions, a precise level of measurement and the use of a pilot study are required in order to improve and ensure the reliability of the quantitative approach (Neuman, 2011b). The questions in the questionnaire

developed for this study were purposely and consistently designed and arranged. A pre-designed outline with the titles of each subsection was used as a guideline when designing the questionnaire: the outline contained the issues that the study intended to investigate. Questionnaire items were then designed according to the outline which ensured that the questionnaire was focused and well-organised to meet the research objectives.

Eleven scale questions in the questionnaire were tested for reliability using

Cronbach’s alpha which is an index of reliability to measure the internal consistency of a test or scale (Tavakol & Dennick, 2011). The higher the score is, the more reliable the scale gets. The value of Cronbach’s alpha for the values tested ranged from 0.70 to 0.95, which is considered good and acceptable. The results of the internal reliability of the two components indicate a high degree of reliability as presented in Table 3.2.

Table 3.2: Cronbach’s alpha reliability coefficients of components

Components Cronbach’s alpha Number of items Number of cases

Views on food security 0.885 5 21

The factors which influence food security

0.768 6 21

3.3.5.4 Final version of questionnaire

After the pilot study and subsequent modification, the final questionnaire with 49 questions was established. The questionnaire was divided into five parts, A, B, C, D and E. The last part (E) invited participants to give their suggestions on the

improvement of food security in Tasmania in order to provide more valuable qualitative data. The structure of the final questionnaire is presented in Table 3.3 (overleaf).

Table 3.3: Structure of the Questionnaire (see Appendix 6 for detail)

Part A: About you Items 1-15 - Gender. - Age group. - Country of origin.

- Language normally spoken at home.

- English proficiency. - Marriage status.

- Number of people in household. - Town/place of residence.

- Length of stay in Tasmania. - Education level.

- Employment status.

- Family or personal income per week.

- Mode of transportation. - Food spend per week.

- Rating of general health status.

Part B: Experiences of food security in Tasmania

Food availability: Items 16-25. Food accessibility: Items 26-28. Food affordability: Items 29-30. Food consumption: Items 31-35.

Part C: Views on food security in Tasmania

Items 36-42.

PartD: Attitudes on coping strategies Items 43-48.

Part E: Own comments Suggestions on how to improve access to healthy food in Tasmania.