NUR 648 Topic 7 Essay: Analyzing Test Data Essay
When a test is scored, the initial result is reported as a raw score, or the number of items that a student answered correctly on the test. Statistical analysis assists you with transforming the raw scores into test grades. Appendix B, “Basic Test Statistics,” provides an overview of the terminology of statistical analysis. Take the time to review some basic statistical references before examining the example of a statistical test report in Table 11.1.
Table 11.1 Sample Test Statistics
Number of items 100
Number of examinees 92
Mean 75.4
Median 77
Low score 52
High score 93 NUR 648 Topic 7 Essay: Analyzing Test Data Essay
Alpha 0.754
Standard deviation 7.7
Standard error of measurement (SEM) 3.8
Mean p value 0.754
Mean point biserial index (PBI) 0.36
Table 11.1 is a sample test analysis report that contains the typical data you would receive from a testing software program. In fact, this report presents more than enough data to help you make informed decisions about test results. Some programs provide even more comprehensive statistics. It is not necessary to make your review too complicated, however; this sample data report is more than sufficient for analysis of a classroom test. Generally, item statistics for small groups of students are relatively unstable. The stability of test analysis data increases as the number of test takers approaches 100. Therefore, when you have a very small group (50 or fewer), you must consider the relative instability of the data when you interpret the analysis. In fact, test and item analysis should not be interpreted dogmatically, no matter how large the number of students. As this discussion illustrates, analysis of test data requires a variety of interpretations, both qualitative and quantitative. The size of the sample is one of the factors you must consider. The first step in test analysis is to review the report to make sure that the data report is complete. Check the number of items and examinees and verify their accuracy. This sample has 100 items, which means the raw score is equal to the percentage correct, and 92 examinees had their answer sheets scored. Once you verify that these figures are correct, you are ready to analyze the results of the test.
- Explain what reliability is and whether this test is reliable based on the information in Table 11.1 (“Sample Test Statistics”). What evidence supports your answer?
Assessments are used in healthcare training and schools to assess the effectiveness of the approaches used in teaching. The findings of the assessment can be used to make appropriate adjustments. Reliability is a statistical term that tests how a particular measure is consistent when done repeatedly (Sürücü & Maslakçi, 2020). According to Yang et al. (2022), test reliability indicates the characteristic quality and dependency of performance. For instance, a reliable test can be likened to an instance that gets a similar result when a particular test is a student repeatedly, thus helping build trust in the obtained results and statistical analysis. The reliability coefficient is used to measure the reliability of specific data. Reliability coefficients between 0.70 to 0.80 are considered reliable, while coefficients below 0.70 are not (Sürücü & Maslakçi, 2020). Low reliability would indicate difficulty in reproducing similar results leading to decreased validity. On the other hand, high reliability indicates that the measurement system produces similar results under the same conditions. As the reliability coefficient approaches 1.00, the level of reliability nears 100%. NUR 648 Topic 7 Essay: Analyzing Test Data Essay
Assessing whether a test is reliable can be determined using various methods, including Test-retest, internal consistency, the split halves method, and the alternative form method. The test-retest method is done at two different times while offering a similar instrument as compared to internal consistency, uses one instrument administered once, and its assessment uses a coefficient alpha (Yang et al., 2022). The alternative form method utilizes two different tools with similar samples and results. Therefore, the reliability coefficient of 0.754 provided in this test shows that it is reliable.
- What is the range for this sample? What information does the range provide and why is it important?
The range is a statistical measure that evaluates variation between the lowest and the highest value in a test. The range provides a basic understanding of how numbers are spread out in the data set, making it easy for calculations using arithmetic. Correct and informed decisions can also be reached when the range is determined. For this data, the highest score is 93, while the lowest is 52. Therefore, the range is 41.
- What is the difference between standard deviation and standard error of measurement? How would the instructor use this information?
Standard deviation measures how values are spread out in a data set, while standard error is the standard deviation of the mean in repeated samples from a population. The standard error is to measure how precise the estimate is of the mean. The information on standard deviation and standard error of measurement is useful to the instructors when making decisions about inferential statistics for data analysis. Furthermore, measurement of central tendency would be possible to determine the distribution that the instructor uses during analysis. NUR 648 Topic 7 Essay: Analyzing Test Data Essay
- Explain the process of analyzing individual items once an instructor has analyzed basic concepts of measurement. Consider the three Ds (difficulty, discrimination, and distractors) in your response.
Item analysis is an essential tool that upholds the effectiveness and fairness of a test. Individual learner responses to individual exam questions are analyzed to evaluate the quality of the exam. The pattern of student errors is also assessed. The analysis highlights the test quality by assessing difficulty, discrimination, and distractors. Item difficulty assesses whether the test was too hard or too easy based on what students get right or wrong. In case everyone correctly gets a particular answer, then it is difficult to understand whoever understood the knowledge deeply as opposed to if everyone gets it wrong. The p-value represents item difficulty. Discrimination assesses the varying levels of knowledge based on percentages by different learners. Comparing the correct answers to the total test score can be used to show desirable discrimination. Item distractors play a vital role in multiple-question exams. The use of appropriate and effective distractors is vital in assessing knowledge.
- If one of the questions on the exam had a p-value of 0.100, would it be a best practice to eliminate the item? Justify your answer.
P value is used as an alternative to the rejection point to provide the least significance at which the null hypothesis would be rejected. It measures the significance of observational data. A p-value < 0.05 is statistically significant as it indicates strong evidence against the null hypothesis (Andrade, 2019). Questions with lower p values than 0.05 are mostly tough and cannot provide a true reflection of learners and should be removed. A p-value of 0.100 would mean that specific questions were answered easily and correctly by learners (Andrade, 2019). Such a question is simple and should be removed as it does not effectively assess learners’ knowledge. Such questions make it hard to differentiate between performing high versus those with low scores. NUR 648 Topic 7 Essay: Analyzing Test Data Essay
- If one of the questions on the exam has a negative PBI for the correct option and one or more of the distractors have a positive PBI, what information does this give the instructor? How would you recommend that the instructor adjust this item?
The mean point biserial index (PBI) in an exam setup is used to measure the consistency of the learner`s overall mark to the candidate’s item mark. It indicates whether getting a question correct correlate either negatively or positively with good performance on the whole exam. The performance of all students is incorporated using PBI. A negative PBI on a question would indicate that learners who had overall poor performance in an exam got the correct response to that particular item. A positive PBI indicates that those scoring high on the total exam answered a test item correctly more frequently than low-scoring students (Andrade, 2019). An item whose distractors have a positive PBI would indicate that majority of learners who had good performance in the whole test failed in this particular item by providing wrong answers (Sajjadi et al., 2021). This information could be used by instructors to make several decisions. The instructor could either list the positive distractors in other questions or eliminate the particular item from the examination. Furthermore, instructors could also choose to use the information to guide teaching, identify learners with poor performance, and scale them to greater heights through training. NUR 648 Topic 7 Essay: Analyzing Test Data Essay
In summation, assessment results provide a broader outlook of learning and determine if learners are making progress in various areas. Therefore, carrying out analysis after an assessment is vital to understanding learners and guiding the next course of action, including assessments to follow.
References
Andrade, C. (2019). The P value and statistical significance: Misunderstandings, explanations, challenges, and alternatives. Indian Journal of Psychological Medicine, 41(3), 210–215. https://doi.org/10.4103/IJPSYM.IJPSYM_193_19
Sajjadi, N. B., Terry, L., & Price, J., III. (2021). Performance metric distribution characteristics of medical school exam items. https://shareok.org/handle/11244/329486
Sürücü, L., & Maslakçi, A. (2020). Validity and Reliability in quantitative research. Business And Management Studies An International Journal, 8(3), 2694–2726. https://doi.org/10.15295/bmij.v8i3.1540
Yang, C. M., Wang, Y.-C., Lee, C.-H., Chen, M.-H., & Hsieh, C.-L. (2022). A comparison of test-retest reliability and random measurement error of the Barthel Index and modified Barthel Index in patients with chronic stroke. Disability and Rehabilitation, 44(10), 2099–2103. https://doi.org/10.1080/09638288.2020.1814429 NUR 648 Topic 7 Essay: Analyzing Test Data Essay
