Below is a discussion on interpreting item statistics from classical test tehory, adapted from the iteman manual. The immediate purpose of item analysis is to determine the difficulty and discriminatory power of each item. Item analysis of in use multiple choice questions in pharmacology. Item analysis interpretation real statistics using excel. Apr 02, 2015 transposing the difficulty and discrimination index for analysis.
A measure of whether an item was too easy or too hard. How well did my test distinguish among students according to the how well they met my learning goals recall that each. The distractor analysis provides a measure of how well each of the incorrect options contributes to the quality of a multiple choice item. We considered the following criteria in constructing a new pool of questions. Spss is a powerful statistical tool for measuring item analysis and an ideal way for educa tors to create and evaluate valuable, insightful classroom testing tools.
Item analysis is the process of collecting, summarizing and using information from students responses to assess the quality of test items. When normreferenced tests are developed for instructional purposes, to assess the effects. Classical test theory for item analysis is most followed. Interpreting the item analysis report stony brook university. For items with one correct alternative worth a single point, the item difficulty is simply the percentage of students who answer an item correctly. Understanding item analyses office of educational assessment. Factor analysis a statistical tool useful in determining whether. Difficulty index, discrimination index and distractor. Item analysis basic concepts real statistics using excel. Correct responses as a percentage of the total group. Jun 29, 2016 the immediate purpose of item analysis is to determine the difficulty and discriminatory power of each item. When normreferenced tests are developed for instructional purposes, to assess the effects of educational programs, or for educational research purposes, it can be very important to conduct item and test analyses. Item analysis examples so, a test item may have an item difficulty of.
Item analysis procedures refer to a set of statistical measures used by testing. It investigates the performance of items considered individually either in relation to some external criterion or in relation to the. An additional analysis that is often reported is the distractor analysis. The following tables show the results from a 5thgrade math exam. Pttexam analysis individual exam item analysis for each item, you will receive a report on how many students selected each response, the item difficulty, and the item discrimination. So we need to transpose the current table to facilitate analysis. The proportion of students answering an item correctly indicates the difficulty level of the item. The proportion of students choosing the correct response is termed item difficulty. Nov, 20 item difficulty item difficulty is simply the percentage of students who answer an item correctly. The current study aimed to carry out a postvalidation item analysis of multiple choice questions mcqs in medical examinations in order to evaluate correlations between item.
Count the number of students who got the correct answer. These problems can be corrected, resulting in a better test, and better measurement. The following item analysis statistics are available. There are several methods of item analysis described in various texts exclusively based on construction of tests. Application of item analysis to assess multiplechoice examinations. Spss is a powerful statistical tool for measuring item analysis and an ideal way for educa tors to create and. When an item analysis is performed on a test, one is almost certain to gain. Difficulty index proportion of students who got an item correct. Below is a discussion on interpreting item statistics from classical test tehory. Within psychometrics, item analysis refers to statistical methods used for selecting items for inclusion in a psychological test. You can access a previously run analysis in the available analysis section.
Difficulty index teachers produce a difficulty index for a test item by calculating the proportion of students in class who got an item correct. Item analysis of in use multiple choice questions in. Tutorial microsoft excel test item analysis sorting the test result. Index match explained an alternative to vlookup duration. Classical test theory and item analysis describes techniques which evaluate the effectiveness of items in tests. The difficulty, discrimination indices and cronbachs alpha were calculated for every exam and then mean values for each index were calculated by lertal 5. Item analysis an effective tool for assessing exam quality.
Item analysis and alpha factor analysis with spss imagine that you are using forsyths ethics position questionnaire click the link to see the questionnaire in some of your research. When an item analysis is performed on a test, one is almost certain to gain additional important insight into the examinees thinking, understanding and testtaking behavior. We have calculated the difficulty and discrimination index for all 30 questions. Assessmentquality test constructionteacher toolsitem. Evaluation of item difficulty index for item analysis. When formalized, the procedure is called item analysis. The correct answer for each item is noted with an asterisk. In addition, item analysis is valuable for increasing instructors skills in test. Careful examination of each of these is critical, as you will use this information to determine the quality of the item. The discrimination index was used as a measure of how well the item.
An item analysis provides three kinds of important information about the quality of test items. When entering the scores, do not type commas, periods, or other special characters. Enter teacher, class information, student names etc. The two principal measures used in item analysis are item difficulty and item discrimination. A measure of whether an item discriminated between students who knew the material well and students who did not. The mean value of the item score test score biserial correlations. Item difficulty pvalue item difficulty is a measure of the proportion of studentssubjects who have answered an item correctly and is most commonly referred to as the pvalue. Select the new reports link in the available analysis section or select view analysis in. Quantitative item analysis utilizes two main values. The maximum item total correlation bound is almost always 1. Now we need to categorise them and prepare a frequency table. Such an item does not discriminate at all between good and poor students, and therefore does not contribute statistically to the effectiveness of. Original research article relationship between difficulty.
Item analysis item response analysis ncss statistical. The item analysis results were then combined with program participant feedback to. Item analysis discrimination and difficulty index 1. In psychometrics, item response theory irt also known as latent trait theory, strong true score theory, or modern mental test theory is a paradigm for the design, analysis, and scoring of tests. The principal measure of item discrimination is the discrimination index. The current study aimed to carry out a postvalidation item analysis of multiple choice questions mcqs in medical examinations in order to evaluate correlations between item difficulty, item discrimination and distraction effectiveness so as to determine whether questions should be included, modified or discarded. These analyses can often be performed for students by personnel in the computer services office. Calculating difficulty, discrimination and reliability index. In the item analysis section, you can view statistics for specific questions in an assessment. Calculating difficulty, discrimination and reliability. Oct 01, 2015 item analysis discrimination and difficulty index 1.
Item analysis can help you evaluate how well your objective items are actually working. Item analysis technique to improve test items and instruction. Sep 10, 2016 tutorial on item analysis in testing, including item discrimination, using the discrimination index, and item difficulty. Algorithm determining item difficulty analysis in computer based test cbt proceedings of 65th thiserd international conference, mecca, saudi arabia, 23rd24 january 2017, isbn. Mean for difficulty index, discrimination index and distractor efficiency were 38. Item difficulty pvalue item difficulty is a measure of the proportion of studentssubjects. Transposing the difficulty and discrimination index for analysis. Item analysis of multiple choice questions at the department. Our psychometric software is widely used around the world, and i often receive questions on how to interpret the output. Tabbed graphs report students scores and item analysis data. This index is equal to the product of the itemscore standard deviation s and the correlation r between the item score and the total test score.
Difficulty index, discrimination index, reliability and. Difficulty index, discrimination index, distracter efficacy, item analysis, multiple choice questions i ntroduction multiple choice questions mcqsitems are the most common method of assessing the knowledge capabilities of undergraduate, graduate, and postgraduate students in medical colleges. Item6 has a high difficulty index, meaning that it is very easy. An item analysis provides three kinds of important. To determine the difficulty level of test items, a measure called the difficulty index is used. This document is prepared to help instructors interpret the statistics reported on the item analysis report and improve the effectiveness of test items and the validity of test scores.
An item analysis is a valuable, yet relatively easy, procedure that teachers can use to answer both of these questions. A snagit video capture that shows how to input the formula to determine the difficulty index for multiple choice items. Two principal measures used in item analysis are item difficulty and item discrimination. Item analysis program itemal performs item analyses of individual test questions as well as entire tests. Hello, does anyone know how to do item analysis difficulty index and. There are three common types of item analysis which provide teachers with three different types of information.
The goal of item response analysis is to determine how well questions on a test discriminate between individuals of varying ability. This is also known as difficulty index, item difficulty, percent correct or pvalue. Item analysis is a technique which evaluates the effectiveness of items in tests. Using remark statistics for test reliability and item analysis. Difficulty index, discrimination index, validity coefficient, and effectiveness of distraction. Difficulty index, discrimination index, distracter efficacy, item analysis, multiple choice questions i ntroduction multiple choice questions mcqsitems are the most common. This means that 70% of the test takers passed the item, and more students in the top group. Tutorial microsoft excel test item analysis sorting. Part iii of the item analysis output, an item quintile table, can aid in the interpretation of part iv of the output. This measure asks teachers to calculate the proportion of students who answered the test item accurately.
A 10 question multiple choice test is given to 40 students. Difficulty index, discrimination index, reliability and rasch measurement analysis 1. Interpret questions q1 through q6 based on the data in figure 1 where the 20 students with the highest exam scores high are compared with the 20 students with the lowest exam scores low. Item difficulty index professional testing, inc test topics. Item difficulty and discrimination analysis programs are often included in the software used in processing exams answered on scantron or other optically scannable forms. When an alternative is worth other than a single point, or when there is more than one correct alternative per question, the item difficulty is the average score on that item divided by the highest number of points for any one alternative. Feb 17, 2015 tutorial microsoft excel test item analysis sorting the test result. For polytomous items items with more than one point, classical item difficulty is the mean response value. In its current incarnation, that would be difficult. Item analysis is an extremely useful set of procedures available to teaching professionals.
Pdf difficulty index, discrimination index and distractor. Item difficulty item difficulty is simply the percentage of students who answer an item correctly. Item4 and item5 are typical items, where the majority of items are responding correctly. The first section describes item difficulty and discrimination indices. Practitioners often depend on item analysis to select items for exam forms and have a variety of options available to them. Test item analysis calculator longleaf elementary school. Tutorial microsoft excel test item analysis sorting the.
The item difficulty index is often called the pvalue because it is a measure of proportion for example, the proportion of students who answer a particular question correctly on a test. Two principal measures used in item analysis are item difficulty and item. Each question has four choices plus blank if the student didnt answer the question. Dec 19, 2012 item analysis can be analyzed by computing. The item difficulty index is a common and very useful analytical tool for statistical analysis, especially when it comes to determining the validity of test questions in an educational setting. Classical test theory for item analysis is most followed method to determine the reliability by calculating difficulty index p score and discriminating index d score and distracter. This number is entered, of course, into the row for the fourth item. Select the new reports link in the available analysis section or select view analysis in the status receipt at the top of the page. Item response analysis is concerned with the analysis of questions on a test which can be scored as either right or wrong. These include the pointbiserial correlation, the agreement.
In this phase statistical methods are used to identify any test items that are not. Of 30 items, 11 items were of higher difficulty level dif i 60%. To determine the difficulty level of test items, a measure called the difficulty index is. It is a scientific way of improving the quality of tests and test items in an item bank.
Hello, does anyone know how to do item analysis difficulty index. Divide by the total number of students who took the test. Using excel test item analysis, difficulty index for mc items. Pdf study of difficulty level and discriminating index of. After you have entered the data, press the compute button.
Ppt item analysis powerpoint presentation free to view. Item analysis with spss software linkedin slideshare. This means that 70% of the test takers passed the item, and more students in the top group than the bottom group got the item correct. Item analysis is a process of examining classwide performance on individual test items. According to wilson 2005, item difficulty is the most essential component of item analysis. It can be used to analyze data collected on optical scan sheets and already processed by the test scoring program or any scored test data that has been placed in a disk file. It is simply the proportion or percentage of students taking the test who answered the item correctly. Tutorial on item analysis in testing, including item discrimination, using the discrimination index, and item difficulty. We will be publishing additional posts on other topics like distractor analysis and item response theory, but you can also check out our tutorial videos on our. The eta coefficient is an additional index of discrimination computed using an analysis of variance with the item response as the independent variable and total score as the dependent variable. Item analysis uses statistics and expert judgment to evaluate tests based on the quality of individual items, item sets, and entire sets of items, as well as the relationship of each item to other items. The item analysis is an important phase in the development of an exam program.742 572 26 1539 1050 1120 240 1207 637 1508 807 1391 747 447 567 1152 612 364 160 63 17 95 1444 32 214 889 1044 502 92 443 1221 777 556 254 622