Five basic reports are available for each test submitted: Item Statistics, Respondent Statistics, Frequency Distribution, Test Statistics and Item Analysis. The reports are described further below. Definitions for some of the terms can be found in the glossary of test statistics terms.
Item Statistics (Sample PDF)
The Item Statistics report shows various statistics for the test. Statistics listed in the report arethe following.
- Sample Size. The total number of forms in the data set.
- Number Missing. The number of responses that are missing (blank).
- Mean. The average of the values in the population.
- Variance. A measure of how spread out a distribution is. It is computed as the average squared deviation of each number from its mean.
- Standard Deviation. A statistic used to characterize the dispersion among the measuresin a given population. It is calculated by taking the square root of the variance.
- Standard Error. The standard deviation of the sampling distribution of that statistic.Standard errors reflect how much sampling fluctuation a statistic will show.
- Point Biserial. A measurement of the discrimination of an item. It indicates the relationship between a response for a given item and the overall test score of the respondent.A high value indicates that the students scoring well on the test scores chose this response.The point biserial statistic applies to grading only.
Respondent Statistics (Sample PDF)
The Respondent Statistics report provides a variety of statistics based on the current scoringoperation.
- T Score. Standard score having a mean of 50 and a standard deviation of 10 (T=10z+50). The standard normal distribution is sometimes called the z distribution. A z score reflects the number of standard deviation above or below the mean a particular score represents.
- Number Correct. The number of correct responses.
- Number Missing. The number of responses that are missing.
Frequency Distribution (Sample PDF)
The Frequency Distribution report illustrates the dispersion of students over the selected interval. The table displays the selected interval, the start range, the end range, and the number of studentsthat fall within that range. In some cases, the range may be a single score. Typically the interval hasa range of 1.
Test Statistics (Sample PDF)
The Test Statistics report provides an overview of the test results, contained in one table.
- Number of Tests Graded. The total number of tests that were graded.
- Number of Graded Items. The number of items on the test that were graded.
- Total Points Possible. The total number of points on the test.
- Maximum Score. The highest score from the graded tests.
- Minimum Score. The lowest score from the graded tests.
- Range of Scores. The distance between the highest and lowest score.
- Mean Score. The average score of all the graded tests.
- Variance. The amount that each score deviates from the mean squared.
- Standard Deviation. A statistic used to characterize the dispersion among the measures in a given population. It is calculated by taking the square root of the variance.
- Kuder-Richardson Formula 20. An overall measure of internal consistency.
Item Analysis (Sample PDF)
The Item Analysis report provides an in-depth look at individual question statistics. Each item displays in a separate table. The correct answer per item (question) is listed in red. If printed on ablack monochrome printer, the correct answer will appear a little darker and in italics.
- Label. The output label designated in the template.
- Value. The corresponding numeric value of each output label.
- Weight. The points assigned to correct, incorrect and missing responses. The weight statistics applies to grading only.
- Frequency. The number of times a particular label was chosen (appears in the data set).
- Percent. The corresponding percentage of the frequency.
- Point Biserial. A measurement of the discrimination of an item. It indicates the relationship between a response for a given item and the overall test score of the respondent. A high value indicates that the students scoring well on the test scores chose this response. The point biserial statistic applies to grading only.
Results Spreadsheet File
A CSV (comma-delimited) spreadsheet file, containing the raw scores of each student in the test, is available for those instructors electing to have the results uploaded to a BlackBoard course. The file contains the student's name (as listed on the bubble sheet), then the student's Identification Number (as listed on the bubble sheet), and the test score.
Grade Reports (Sample PDF)
The Grade Reports provide a detailed student grade report for each student included in the grade operation. You may print these reports and give them to your students. The report gives a table of basic statistics. Be aware that printing this report could generate a lot of paper since at least onepage is printed for each student who took the test.
- Total Score. Total raw score.
- Responses. The questions and student's answers are displayed. For an incorrect answer, the correct answer is also displayed
For More Information
If the above reports do not meet your needs, contact Test & Evaluation Services (515-294-1832 or ) for your special needs or clarification of the above reports.
For assistance in interpreting or analyzing the test statistics, contact the Statistics Help Room (114 Snedecor Hall, 515-294-8927) for a referral to an appropriate consultant.
Glossary of Test Statistics Terms
These definitions have been reprinted from the Remark Classic OMR documentation for the system used by Test and Evaluation Services.
|The total number of tests that were graded.|
|The number of items on the test that were graded.|
|The total number of points on the test.|
|The highest score from the graded tests.|
|The lowest score from the graded tests.|
|The median of the scores from the graded tests.|
|The distance between the highest and lowest scores.|
|Values that divide a sample of data into one hundred groups containing (as far as possible) equal numbers of observations. For example, 25% of the data values lie below the 25th percentile.|
|The difference between the 75th percentile and the 25th percentile.|
|The average score of all of the graded tests.|
|The amount that each score deviates from the mean squared(by multiplying it by itself).|
|A statistic used to characterize the dispersion among measures in a given population.|
(1, 5, 95, and 99%)
|A confidence interval gives an estimated range of values that is likely to include an unknown population parameter, the estimated range being calculated from a given set of sample data. If independent samples are taken repeatedly from the same population, and a confidence interval is calculated for each sample, then a certain percentage (confidence level) of the intervals will include the unknown population parameter. Remark Classic OMR calculates Confidence Intervals of 1%, 5%, 95% and 99%.|
|An overall measure of internal consistency.|
|A coefficient that describes how well a group of items focuses on a single idea or construct.|