Review What type of reliability measure is giving a test to the same learners twice with a time interval between tests?
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Lê Minh Sơn đang tìm kiếm từ khóa What type of reliability measure is giving a test to the same learners twice with a time interval between tests? được Cập Nhật vào lúc : 2022-08-25 17:38:03 . Với phương châm chia sẻ Thủ Thuật Hướng dẫn trong nội dung bài viết một cách Chi Tiết Mới Nhất. Nếu sau khi tham khảo nội dung bài viết vẫn ko hiểu thì hoàn toàn có thể lại Comment ở cuối bài để Tác giả lý giải và hướng dẫn lại nha.There are four procedures in common use for computing the reliability coefficient (sometimes called the self-correlation) of a test. These are: 1. Test-Retest (Repetition) 2. Alternate or Parallel Forms 3. Split-Half Technique 4. Rational Equivalence.
Nội dung chính- 1. Test-Retest Method:2. Alternate or Parallel Forms Method:3. Split-Half Method or Sub-divided Test Method:4. Method of Rational Equivalence:What type of reliability is use when the same instrument is administered twice to the same group of subjects and the correlation coefficient is determined?What type of reliability is where the test was administered twice to the same group with a time interval not to exceed 6 months?What is the testWhat is the type of the reliability when measured by administering two tests identical in all aspects except the actual wording of items?
1. Test-Retest Method:
To estimate reliability by means of the test-retest method, the same test is administered twice to the same group of pupils with a given time interval between the two administrations of the test.
The resulting test scores arc correlated and this correlation coefficient provides a measure of stability, that is, it indicates how stable the test results are over a period of time. So it is otherwise known as a measure of stability.
The estimate of reliability in this case vary according to the length of time-interval allowed between the two administrations. The product moment method of correlation is a significant method for estimating reliability of two sets of scores.
Thus, a high correlation between two sets of scores indicates that the test is reliable. Means, it shows that the scores obtained in first administration resemble with the scores obtained in second administration of the same test.
In this method the time interval plays an important role. If it is too small say a day or two, the consistency of the results will be influenced by the carry-over effect, i.e., the pupils will remember some of the results from the first administration to the second.
If the time interval is long say a year, the results will not only be influenced by the inequality of testing procedures and conditions, but also by the actual changes in the pupils over that period of time.
Time gap of retest should not be more than six months. Time gap of retesting fortnight (2 weeks) gives an accurate index of reliability.
Advantages:Self-correlation or test-retest method, for estimating reliability coefficient is generally used. It is worthy to use in different situations conveniently. A test of an adequate length can be used after an interval of many days between successive testing.
Disadvantages:1. If the test is repeated immediately, many subjects will recall their first answers and spend their time on new material, thus tending to increase their scores—sometimes by a good giảm giá.
2. Besides immediate memory effects, practice and the confidence induced by familiarity with the material will almost certainly affect scores when the test is taken for a second time.
3. Index of reliability so obtained is less accurate.
4. If the interval between tests is rather long (more than six months) growth factor and maturity will effect the scores and tends to lower down the reliability index.
5. If the test is repeated immediately or after a little time gap, there may be the possibility of carry-over effect/transfer effect/memory/practice effect.
6. On repeating the same test, on the same group second time, makes the students disinterested and thus they do not like to take part wholeheartedly.
7. Sometimes, uniformity is not maintained which also affects the test scores.
8. Chances of discussing a few questions after the first administration, which may increase the scores second administration affecting reliability.
2. Alternate or Parallel Forms Method:
Estimating reliability by means of the equivalent form method involves the use of two different but equivalent forms of the test. Parallel form reliability is also known as Alternative form reliability or Equivalent form reliability or Comparable form reliability.
In this method two parallel or equivalent forms of a test are used. By parallel forms we mean that the forms arc equivalent so far as the content, objectives, format, difficulty level and discriminating value of items, length of the test etc. arc concerned.
Parallel tests have equal mean scores, variances and inter co-relations among items. That is, two parallel forms must be homogeneous or similar in all respects, but not a duplication of test items. Let the two forms be Form A and Form B.
The reliability coefficient may be looked upon as the coefficient correlation between the scores on two equivalent forms of test. The two equivalent forms are to be possibly similar in content, degree, mental processes tested, and difficulty level and in other aspects.
One form of the test is administered on the students and on finishing immediately another form of test is supplied to the same group. The scores, thus obtained are correlated which gives the estimate of reliability. Thus, the reliability found is called coefficient of equivalence.
Gulliksen 1950: has defined parallel tests as tests having equal means, equal variance and equal inter co-relations.
Guilford: The alternative form method indicates both equivalence of content and stability of performance.
Advantages:This procedure has certain advantages over the test-retest method:
1. Here the same test is not repeated.
2. Memory, practice, carryover effects and recall factors are minimised and they do not effect the scores.
3. The reliability coefficient obtained by this method is a measure of both temporal stability and consistency of response to different item samples or test forms. Thus, this method combines two types of reliability.
4. Useful for the reliability of achievement tests.
5. This method is one of the appropriate methods of determining the reliability of educational and psychological tests.
Limitations:1. It is difficult to have two parallel forms of a test. In certain situations (i.e. in Rorschach) it is almost impossible.
2. When the tests are not exactly equal in terms of content difficulty, length, the comparison between two set of scores obtained from these tests may lead to erroneous decisions.
3. Practice and carryover factors cannot be completely controlled.
4. Moreover, administering two forms simultaneously creates boredom. That is why people prefer such methods in which only one administration of the test is required.
5. The testing conditions while administering the Form B may not be the same. Besides, the testes may not be in a similar physical, mental or emotional state both the times of administration.
6. Test scores of second form of the test are generally high.
Although difficult, carefully and cautiously constructed parallel forms would give us reasonably a satisfactory measure of reliability. For well-made standardised tests, the parallel form method is usually the most satisfactory way of determining the reliability.
3. Split-Half Method or Sub-divided Test Method:
Split-half method is an improvement over the earlier two methods, and it involves both the characteristics of stability and equivalence. The above discussed two methods of estimating reliability sometimes seems difficult.
It may not be possible to use the same test twice and to get an equivalent forms of test. Hence, to overcome these difficulties and to reduce memory effect as well as to economise the test, it is desirable to estimate reliability through a single administration of the test.
In this method the test is administered once on the sample and it is the most appropriate method for homogeneous tests. This method provides the internal consistency of a test scores.
All the items of the test are generally arranged in increasing order of difficulty and administered once on sample. After administering the test it is divided into two comparable or similar or equal parts or halves.
The scores are arranged or are made in two sets obtained from odd numbers of items and even numbers of items separately. As for example a test of 100 items is administered.
The scores of individual based on 50 items of odd numbers like 1, 3, 5,.. 99 and scores based on even numbers 2, 4, 6… 10 are separately arranged. In part ‘A’ odd number items are assigned and part ‘B’ will consist of even number of items.
After obtaining two scores on odd and even numbers of test items, co-efficient of correlation is calculated. It is really a correlation between two equivalent halves of scores obtained in one sitting. To estimate reliability, Spearman-Brown Prophecy formula is used.
The Spearman-Brown formula is given by:
in which r11 = the reliability of the whole test.
r11/22 = the coefficient of correlation between two half tests.
Example 1:
A test contains 100 items. All these items are arranged in order of difficulty as one goes from the first to the hundredth one. Students answer the test and the test is scored.
The scores are obtained by the students in odd number of items and even number of items are totaled separately. The coefficient of correlation found between these two sets of scores is 0.8.
The reliability of the whole test (or)
While using this formula, it should be kept in mind that the variance of odd and even halves should be equal, i.e.
If it is not possible then Flanagan’s and Rulon’s formulae can be employed. These formulae are simpler and do not involve computation of coefficient of correlation between two halves.
Advantages: 1. Here we are not repeating the test or using the parallel form of it and thus the testee is not tested twice. As such, the carry over effect or practice effect is not there.
2. In this method, the fluctuations of individual’s ability, because of environmental or physical conditions is minimised.
3. Because of single administration of test, day-to-day functions and problems do not interfere.
4. Difficulty of constructing parallel forms of test is eliminated.
Limitations:1. A test can be divided into two equal halves in a number of ways and the coefficient of correlation in each case may be different.
2. This method cannot be used for estimating reliability of speed tests.
3. As the lest is administered once, the chance errors may affect the scores on the two halves in the same way and thus tending to make the reliability coefficient too high.
4. This method cannot be used in power tests and heterogeneous tests.
Inspite of all these limitations, the split-half method is considered as the best of all the methods of measuring test reliability, as the data for determining reliability are obtained upon on occasion and thus reduces the time, labour and difficulties involved in case of second or repeated administration.
4. Method of Rational Equivalence:
This method is also known as “Kuder-Richardson Reliability’ or ‘Inter-Item Consistency’. It is a method based on single administration. It is based on consistency of responses to all items.
The most common way for finding inter-item consistency is through the formula developed by Kuder and Richardson (1937). This method enables to compute the inter-correlation of the items of the test and correlation of each item with all the items of the test. J. Cronbach called it as coefficient of internal consistency.
In this method, it is assumed that all items have same or equal difficulty value, correlation between the items are equal, all the items measure essentially the same ability and the test is homogeneous in nature.
Like split-half method this method also provides a measure of internal consistency.
The most popular formula is Kuder-Richardson i.e. KR-21 which is given below:
q = – p
p = 1 – q
An example will help us to calculate p and q.
Example 2:
60 students appeared a test and out of them 40 students have given correct response to a particular item of the test.
p = 40/60 = 2/3
This means y portion of students have given correct response to one particular item of the test. In which 20 students have given incorrect response to that item.
Thus q = 20/60 or 1 – 40/60
For each item we are to find out the value of p and q then pq is summated over all items to get ∑pq . Multiply p and q for each item and sum for all items. This gives ∑pq.
Advantages:1. This coefficient provides some indications of how internally consistent or homogeneous the items of the tests are.
2. Rational equivalence is superior to the split-half technique in certain theoretical aspects, but the actual difference in reliability coefficients found by the two methods is often negligible.
3. Split-half method simply measures the equivalence but rational equivalence method measures both equivalence and homogeneity.
4. Economical method as the test is administered once.
5. It neither requires administration of two equivalent forms of tests nor it requires to split the tests into two equal halves.
Limitations:1. The coefficient obtained by this method is generally somewhat lesser than the coefficients obtained by other methods.
2. If the items of the tests are not highly homogeneous, this method will yield lower reliability coefficient.
3. Kuder-Richardson and split-half method are not appropriate for speed test.
4. Different KR formula yield different reliability index.
What type of reliability is use when the same instrument is administered twice to the same group of subjects and the correlation coefficient is determined?
Test-retest reliability is a measure of reliability obtained by administering the same test twice over a period of time to a group of individuals. The scores from Time 1 and Time 2 can then be correlated in order to evaluate the test for stability over time.What type of reliability is where the test was administered twice to the same group with a time interval not to exceed 6 months?
Test-retest reliability The test-retest reliability method in research involves giving a group of people the same test more than once over a set period of time.What is the test
Test-retest reliability assumes that the true score being measured is the same over a short time interval. To be specific, the relative position of an individual's score in the distribution of the population should be the same over this brief time period (Revelle and Condon, 2022).What is the type of the reliability when measured by administering two tests identical in all aspects except the actual wording of items?
Test-retest reliability . Test-retest reliability is a measure of consistency between two measurements (tests) of the same construct administered to the same sample two different points in time. If the observations have not changed substantially between the two tests, then the measure is reliable. Tải thêm tài liệu liên quan đến nội dung bài viết What type of reliability measure is giving a test to the same learners twice with a time interval between tests?
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