The research instruments

3.6.1 Tests

The achievement test consisted of ten items or questions that assessed learner’s mathematical knowledge and skills in the concept of linear functions. The questions were closed - ended questions. The test questions were given to three educators who had more than ten years of teaching experience in Mathematics to moderate and evaluate the content of the test (Table 3.1). There was also a pilot study conducted at another school to detect any errors and ambiguities before the actual study. Table 3.6 (Appendix C) shows the results of the pilot study.

3.6.1.1 The pre-test

The similarity of the two groups was compared using a pre-test. This was administered prior to conducting the experiment (Wiersma & Jurs, 2009). The focus was on the drawing and interpretation of graphs. Pre-test (Appendix A) shows the content of this test.

3.6.1.2 The post-test

The post-test was administered at the end of the intervention to the learners on both groups. The experimental group used computers as the intervention, while the control group used the traditional pen and paper method. Their test scores were analysed. Post-test (Appendix B) shows the content of this test.

3.6.2 The Questionnaire

The questionnaire (Appendix C) for this study was compiled by the researcher. Cronbach‘s alpha was calculated for reliability (Table 3.1), detailed calculation is shown in Appendix B1. A ten-item questionnaire, with closed-end questions was used. The questionnaire was only administered to the experimental group after the experimental period. A Likert four type scale was used to measure the degree at which learners agree or disagree to an item on the questionnaire. This scale measure one item at a time and provides a range of answers to a question. The rating on the scale ranged from strongly agree to strongly disagree (Neuman, 2011) The questionnaire was employed to measure the attitude of learners towards Mathematics after learning linear functions using computers. The questionnaire measured the general attitude of learners towards Mathematics, both positive and

negative. Moreover, a pilot study was done for the questionnaire to check clarity of questions, the layout and the instructions.

In a study such as this study it is imperative to take cognisance of reliability, which is presented below.

3.6.3 Reliability

Reliability has to do with the consistency of the measurements obtained. Additionally, consistency is concerned with the similarity of the scores overtime (Arthur, Waring, Coe & Hedges, 2012). The reliability of the questionnaire can be monitored by asking similar questions in different parts of the questionnaire, to check the extent at which respondents are consistent in their answers. Reliability for this study was calculated on the results of the pilot study (n=10) and yielded the alpha value as α=0.911. This indicates a high reliability of the questionnaire (Table 3.3); therefore the questionnaire could be used in this empirical study. The detailed reliability for the questionnaire responses may be seen in Appendix B1.

Table 3.1 Reliability Statistics of the questionnaire

Cronbach's

Alpha Cronbach's Alpha Based on Standardized Items N of Items

.911 .918 10

This study ensured the internal reliability of the test items, whereby the Cronbach alpha was calculated using SPSS Version 22 (SPSS 2013). No item was removed; this means the test remained at 10 items (Table 3.2), detailed calculation is shown in Appendix B2. The alpha value for the test was 0,807 which indicated a high reliability. The reliability accepted alpha value is 0.7. Therefore the test was reliable and it was used in the study. Furthermore reliability was improved by asking experts to moderate the tests. A detailed reliability for the test may be found in Appendix B2. Table 3.2 Reliability Statistics of the test

Cronbach's Alpha

Cronbach's Alpha Based on

.807 .807 10

Closely related to reliability is validity and the onus rests upon the researcher to ensure validity.

3.6.4 Validity

Validity means the extent to which scientific concepts match the reality and the degree to which explanations are accurate (McMillan & Schumacher, 2010). There are different types of validity, according to Tomal (2010). Content validity refers to the test to measure subject content and may be done by experts in the field who gave their expert opinions whether tests are valid. Internal validity focuses on the viability of causal links between independent and dependent variables. The link refers to the relationship between the intervention and test scores while external validity refers to the generalizability of the results.

The validity for these instruments was ensured, firstly, through the pre-test and post- test that was taken to experts for moderation. The panel of experts consisted of the Deputy Principal for curriculum; Departmental Head in Mathematics, and Grade10 to 12 post-level 1 teacher, all have more than ten years of teaching experience in Mathematics. The experts were asked to independently judge whether the test items reflected the content domain of the study. This is to determine whether the task represents the exact content related to the topic. They examined the content of the questions items for the test (Table 3.3) shows the results of validity of the test.

Table 3.3 Validity of the test

QUESTION HOD TEACHER 1 TEACHER 2

1 Y Y Y 2 Y Y Y 3 Y Y Y 4 Y N N 5 Y Y Y 6 Y Y Y 7 Y Y Y 7.1.1 Y Y Y 7.1.2 Y N Y 7.1.3 Y Y Y YES-Y NO-N

The experts’ opinions and suggestions were considered for the amendments that were made. Furthermore, the style of the testing used in these instruments was familiar to the learners. Secondly a pilot study was conducted, and this helped the researcher to be aware of the unforeseen problems that could emerge during investigation. Finally, all mistakes were corrected before the tests were used.

The researcher calculated the Content Validity Index (CVI) which was computed using the following formula:

The content validity index (CVI) was therefore computed as follows:

𝑻𝒐𝒕𝒂𝒍 𝒏𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝒊𝒕𝒆𝒎𝒔 𝒊𝒏 𝒕𝒉𝒆 𝒕𝒆𝒔𝒕 𝒅𝒆𝒄𝒍𝒂𝒓𝒆𝒅 𝒗𝒂𝒍𝒊𝒅 𝒃𝒚 𝒂𝒍𝒍 𝒇𝒐𝒖𝒓 𝒓𝒂𝒕𝒆𝒓𝒔 𝑻𝒉𝒆 𝒕𝒐𝒕𝒂𝒍 𝒏𝒖𝒎𝒃𝒆𝒓 𝒐𝒇 𝒕𝒉𝒆 𝒊𝒕𝒆𝒎𝒔 𝒊𝒏 𝒕𝒉𝒆 𝒕𝒆𝒔𝒕

For the learners’ test, the CVI was found to be 0.80, which is greater than the acceptable value of 0.7.

The same panel of experts were also asked to assess the items in the questionnaire. Their results were used to calculate the validity of the questionnaire. Amendments were made were necessary. Table 3.4 shows the results from the experts.

Table 3.4 Validity of the questionnaire

ITEMS HOD TEACHER 1

A Y Y B Y Y C Y Y D Y N E Y Y F Y Y G Y Y H Y N I Y Y J Y Y

For the learners’ questionnaire, the CVI was found to be 0.80, which is greater than the acceptable value of 0.7.