PREPARATION FOR THE STUDY

2.6.1 Obtaining written, informed consent

The researcher firstly obtained written, informed consent from the Free State Department of Education (Appendix F). Subsequently the principals of the selected schools were contacted to discuss the intended research project and to obtain written, informed consent from each school principal (Appendix G). The tuck shop managers were contacted next to obtain consent (Appendix H). Parental consent forms were given to selected learners, two weeks before the study and these forms were collected from the school one week before data collection. The return of signed consent forms from both schools was very poor; therefore

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the date for submission of consent forms was extended until the day of the study. Parental consent forms were available in Afrikaans, English and Sesotho to provide them with the necessary information about the research in their preferred language (Appendix I). All learners who agreed to participate completed the assent form for learners (Appendix C).

2.6.2 Standardisation of researchers

The researcher trained a research assistant to ensure that procedures followed during the study were standardised in accordance with the research protocol. The assistant had to be able to speak Afrikaans fluently, have at least a matric qualification and had to enjoy working with learners. The assistant received a training manual indicating the aims and objectives of the study, information on the participants, location of selected schools, procedures to be followed during data collection and methods to ensure validity and reliability. She was also instructed about the correct manner to conduct focus group discussions and she was provided with the discussion guide for the focus groups. The process of obtaining informed consent from parents and informed assent from learners was discussed in detail. The research assistant assisted the researcher during the focus group discussions and helped during the administration of the questionnaires.

2.6.3 Pilot study

To ensure content validity of the questionnaire four experts (two primary school teachers and two dietitians) gave recommendations regarding the relevance of the contents, the level

of difficulty and the appropriateness for the target group.89 The primary school teachers

noted that learners of all age groups between grades 2 to 7 would be able to complete the questionnaire on their own, but they recommended that questionnaires should be filled in step-by-step with grades 2 and 3 learners since some of them struggle to read with comprehension. They also noted that younger learners tend to write very big and are used to writing between two lines at once. Some questions were rephrased but in general both dietitians noted that the questionnaire touched on all aspects in order to measure learners’

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perceptions, attitudes and behaviour towards healthy eating. The dietitians were concerned about the word “snackwich” as they felt that all learners might not understand the word. The picture of the snackwich was therefore replaced with a picture of a pie in the final questionnaire (Appendix B).

To ensure validity and reliability of the questionnaires and processes for the main study, the researcher and assistant conducted a pilot study at school C in November 2010, where 36 learners were selected by means of random sampling. Six learners in each of the participating grades (grades 2 to 7) were recruited and learners in grade 2 and grade 4 were asked to take part in two separate focus group discussions.

The same procedures were followed as for the main study. The researcher recorded the time needed to complete questionnaires. It was determined that older learners completed the questionnaire in more or less 10 minutes while younger learners took about 20 minutes. The focus group discussions lasted between 15 and 20 minutes. The researcher and assistant kept notes of the questions in the questionnaire that learners misunderstood. The questionnaire was re-administrated to the same sample of learners after two weeks to obtain internal reliability of the questionnaire. Cronbach’s alpha statistics indicated that the questionnaire is reliable for measuring attitude and behaviour. The internal reliability of the perception questions was inconsistent thus the questionnaire was adapted after the pilot study was completed and the adapted questionnaire was used for the main study (Appendix B). Phrases of questions in section D of the questionnaire was re-written so that both older and younger learners could understand them. A negatively worded question was omitted in the final questionnaire and the sequence of questions 10 to 12 was changed, since most learners were unable to mark only one choice of food, beverage and a snack for their lunchbox after marking all the fruits and vegetables that they liked in the previous questions. With the exception of the questions about pocket money and the amount spent at the tuck shop, which was removed, the focus group discussion guide was kept the same for the main study (Appendix D).

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2.6.4 Validity

To assess the validity of the questionnaire, face validity and content validity were tested. Face validity is the extent to which an instrument looks like it is measuring a particular

characteristic.90 This type of validity is defined by the researcher’s subjective judgement and

it is an assessment of whether the question truly measures behaviour, attitude or opinion.91

To ensure face validity, statistical results obtained from the pilot study were assessed. Content validity is a way of assessing validity by ensuring that all the components of a

variable are measured.92 To ensure content validity, the researcher asked four experts

consisting to scrutinise the content of the questionnaire to determine the validity of the questionnaire for measuring the perceptions, attitudes and behaviour of primary school

learners towards healthy eating.90

Internal validity (credibility) refers to the “trueful picture” the researcher sketches, whether it “rings true”, or whether the researcher and participants would agree on the description and interpretation of what has been seen or said, i.e. a type of mutual understanding or

agreement between them.72,93 In this study, strategies to improve the internal validity

included triangulation in data collection and analysis, auto recording of data and the use of

participant language in reporting.72,93 Detailed transcriptions were also made to assist with

the interpretation in the data analysis process. To further ensure internal validity, an independent person was appointed to code some of the data that could be used for a

comparison and verification of the coding done by the researcher.94

As in quantitative research, external validity in qualitative research has to do with the generalisability or the extension of the findings. Because qualitative research largely depends on the specific context or environment of the study, generalisability is not the goal, but researchers must ensure that the findings are generalisable to the target population. The careful selection of participants (random sampling in the case of this study) and detail in the

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2.6.5 Reliability

In this study, several measures were taken to ensure reliability. To determine the internal reliability of the questionnaire, data obtained from the pilot study was evaluated statistically per construct by using Cronbach’s alpha. Cronbach’s alpha is a measure of internal consistency of the items per construct and a coefficient close to +1.00 would reflect a high internal reliability of the questionnaire.95 To further evaluate reliability, the questionnaire was re-administrated to the same sample of learners in school C after two weeks.

In qualitative studies the researcher is the instrument of data collection and interpretation. A possible disadvantage is therefore the possibility of subjectivity and bias which has to be

dealt with.72,93 The detailed records kept of the data collected and the data analysis

procedure was an additional measure for ensuring reliability. All these measures assisted in addressing possible researcher bias and subjectivity.