a. Explain four reasons why a researcher needs to sample during research. (12 marks) Use the problem statement to answer question 1b . 'The purpose of the study was to investigate the impact of systematic cooperative learning and test-taking strategies on one component of academic performance, the recall of text material'. b. i. Which type of research was done? ii. What is the dependent variable? iii. What is/are the independent variable(s) in the study? (2 marks) (2 marks) iv. What scale of measurement is the variable 'academic performance'? (2 marks) (2 marks) a. Enumerate four criteria for evaluating research hypotheses. (8 marks) b. i. Differentiate between null and alternative hypotheses. (4 marks) ii. State two examples each of null and alternative hypotheses. (4 marks) iii. State two sources of research problems. (4 marks) Page 1 of 2

<p> <br />1. a. Sampling is essential in research for various reasons. Firstly, it allows researchers to obtain a subset of the population that is representative, ensuring that the findings can be generalized. Secondly, sampling can save both time and resources, as studying the entire population might be impractical. Thirdly, it ensures the research is feasible, especially when dealing with large populations. Lastly, accurate and reliable findings can be obtained through sampling if done correctly.<br />2. b. i. The type of research done is descriptive as it aims to investigate the impact of certain strategies. <br /> ii. The dependent variable is what is being measured or observed. In this case, it is the recall of text material.<br /> iii. The independent variables are the factors or conditions that are manipulated or categorized to determine their effect on the dependent variable. Here, they are systematic cooperative learning and test-taking strategies.<br /> iv. The variable 'academic performance' is measured on an ordinal scale as it involves ranking or order, such as grades or class ranks.<br />3. a. Research hypotheses should be clear, meaning they should be easily understandable. They should be relevant to the study and contribute to the existing body of knowledge. They should also be testable, meaning they can be empirically tested using appropriate methods. Lastly, they should be specific, detailing the expected relationship or difference.<br />4. b. i. The null hypothesis (often denoted as H0) is a statement that there is no significant difference or relationship. In contrast, the alternative hypothesis (often denoted as H1 or Ha) states that there is a significant difference or relationship.<br /> ii. An example of a null hypothesis might be stating that there is no significant difference in the performance of students taught using two different methods. The corresponding alternative hypothesis would state that there is a significant difference.<br /> iii. Research problems can arise from various sources. One common source is a literature review, where gaps in existing research are identified. Another source is observations or personal experiences that highlight a particular issue or phenomenon that requires investigation.<br /></p>