Saturday, May 9, 2015

Reliability and Validity Matrix


For each of the tests of reliability and validity listed on the matrix, prepare a 50- to 70-word description of the test’s application. Describe what conditions these reliability types would be used for, as well as when they would be inappropriate. Then, for each test, prepare a 50- to 70-word description of the strengths and a 50- to 70-word description of the weaknesses.

Test of reliability
Application and appropriateness
Advantages
Disadvantages
Internal consistency

In internal consistency deals with assessing consistency of internal items or internal consistency of the items on a test.  This is used in order to estimate the reliability of items that are on the test without the need to develop alternate or additional forms of a test or having to give the test more than one time. Internal consistency employs a single measurement to estimate a test’s reliability. 
One of the greatest advantages comes from only needing to administer the test one time and thus it provides a cost efficient and effective nature to the test taking process. Another advantage comes from internal consistency, which can be gained through a wide measurement of tests and through a variety of items.  
One disadvantage is that high reliabilities with this method may actually be considered a weakness as it can indicate a redundancy in the test items and measures used. Another disadvantage comes from the results not being taken from the theory, which results in all variables being considered. The results are never perfect but rather have to be theorized to try to perfect the results.
Test or retest


With the use of this test a developer provides the test twice to an individual on different occasions. The developer compares the two scores in order to assure the testers haven’t changed from one test to the next. This method allows a way to estimate reliability, as there is a higher correlation between testers taking tests within shorter amounts of time between each test.
The advantage of this method is that it produces a lower score when it is compared with other methods. The time frame being shorter between first test and retest provide correlations between timeframes and lower scores being produced. Another advantage is that the method uses a single score or rater code.
Some disadvantages to the method is that it can be prone to weaknesses like from carryover effects attributing to or causing errors that are found in test scores. Timeframes can also affect scores produced by testers on the retake test. The method can also prove to be more costly since it requires the test be given multiple times and it can lack in reliability.
Parallel and alternate forms


Parallel test exist when all the additional or alternate forms are equal in means and variances of the observed test scores. The theory behind it is that means on parallel forms correlate equally to the true score of the test. Alternate forms are a method in which different test versions have been created to parallel the original test.
Advantages of these tests include that it can minimize effects that memory of content may have on administering previous forms of the test.  The tests may also provide stable scores and information in certain circumstances when measuring certain constructs.  Another advantages comes from being able to estimate reliability without having to develop another form of the test.
Disadvantages come from having to develop alternate forms of the test, which can be expensive as well as time consuming. Errors may result in variance or item sampling when trying to compute the alternate or parallel form of the reliability coefficient. Finally, the person taking the test may have performance issues, which are affected by a specific for of the test, done to the items included on that test.
Test of validity
Application and appropriateness
Strengths
Weaknesses
Content validity


Content validity is concerned with scrutinizing the content of the test as well as the extent to which the test measures represents all the facets for a given construct. A judgment is made of how adequately the test is able to sample behaviors that represent the universe of behavior in which the test was created for.
Advantages of the method involve defining as well as finding domain of items in which a creator of the test wants to measure. It helps to increase a test’s validity and leads to content validity. Items on the test go with things wanting to be measured without deviating from items that want to be measured.
The disadvantages of this method are that can require experts to design, develop, and evaluate the test and scores. This makes the test both expensive as well as time consuming.  Furthermore, the test may have a need to cover a variety of items and information that can be long for either administering or taking the test.
Criterion related


Criterion related is used in order to demonstrate accuracy of a procedure or measure by comparing the procedure with another one to demonstrate it to be valid. It is used as a judgment of the adequacy of the test to basically predict or infer a person’s score on a given subject.
One advantage of the method is that involves use of two estimators to demonstrate validity of a test that has been given. This method works for academic use in being able to predict scores. Additionally it can work well in the determination of how certain things like traits develop overtime.
Disadvantages associated with the method include accuracy. Individuals change overtime which can lead to problems with accuracy or reliability with the tests. Another disadvantage is in the change to academics itself, individuals learn one thing and it is changed on the test or it needs to be changed on the test making it costly to do so.
Construct


Construct deals with a test or an experiment being able to measure what it claims to do.  It refers to the operational definition of a variable actually reflecting the theoretical meaning of a certain concept.  This method requires judgment about appropriateness of the scores drawn from the inferences in a person’s standings. 
One advantages of this method include that domain of an item or the behavior wanting to be measured is obtained. The domain behavior is kept in mind as the items on the experiment or test are reviewed so all items can show a relationship with behaviors wishing to be measured.
Disadvantages of the method require experts in the areas of the test or experiments to help with the tests. Additionally experts are also needed in the use of the experiments and evaluation of tests that makes the test more time consuming as well as being more costly to create, perform, as well as evaluate. Finally, the mere development of the test is not easy either.


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