qualities of agood tool

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qualities of a good eva

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Qualities of a good evaluation tool:

Qualities of a g ood evaluation tool Prasanth.P Asst.Professor in Educational Psychology Govt. I.A.S.E, Thrissur

1.Objectivity:

1.Objectivity objective-basedness is the prime requirement of any evaluation tool.

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A tool is said to be objective if it is free from personal biases and prejudices in its scoring.

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When the questions used in a tool / test is too vague or loosely stated and the scoring depends upon the arbitrary judgments of the examiner, then that tool is said to be subjective Subjectivity is the opposite of subjectivity

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How to make a tool objective?

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Objectivity can be ensured by taking precautions at the time of constructing the test items as well as while scoring the answers.

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The tests should specifically pinpoint out what is to be expected from the learners from that particular question. Eg: indication such as “ explain the meaning of………with the help of an example”, “state two reasons for..” Enumerate the sequetial steps involved in the procedure adopted for……………”

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a scheme of evaluation has to be prepared at the time of construction of the questions and it should be supplied to the examiners and asked them to strictly follow the scheme while evaluation

2.Validity :

2.Validity A test is said o be valid if it measures what it intended to measure

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“ the test of validity may be defined as the accuracy with which it measures what it is intended to measure or as the degree in which it approaches infallibility in measuring what it purports to measure”--- Lindquist.

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Validity is the judgment about a test's ability to measure what it is intended or supposed to measure. It refers to the appropriateness, meaningfulness and usefulness of inferences made from a test score.

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If a test does not hit the intended target, no value can be attached to the results of such a test and it is termed as an invalid test.

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If a test is designed to measure the linguistic ability of students, it should measure that ability.

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Validity depends upon a lot of factors.

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A test should measure what it intended to measure And a test should not measure anything that is unwanted.

Rational validity :

Rational validity It is the result if rational or logical analysis made by experts with a professional outlook leading to the judgment about the extend of validity it possesses.

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We know the achievement test is normally developed to agree with the course content. Validity of such test depends upon how well the test content agrees with the course content. This can be checked by a logical analysis of the course content and the test contents.

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In empirical validity, validity of a test is checked by using some statistical measures .

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There are different types of validity under these two categories.

Content validity:

Content validity If the test content agrees with the course content with regard to two dimensions- instructional objectives and subject matter- then the test may be said to posses content validity.

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The facts, concepts, principles etc involved in a topic forms the subject content , where as the changes in the learner as evidenced by his understandings, skills, interests, attitudes etc form the instructional objectives .

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If a test possesses objective basedness and comprehensiveness, then it will posses content validity.

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Content validity is often referred to as “curricular validity” , “ Logical or rational validity ”, “ face validity ”, or “ Judgmental validity ”.

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Content validity is very relevant in the case of achievement tests The framers of test should first of all make a thorough analysis of the curriculum with the help of text books, findings of the study groups and opinions of the expert teachers.

Predictive validity:

Predictive validity Also called criterion related or statistical validity

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if a test meant for selecting a candidates for a particular job, should predict whether the selected ones will be really successful in that , then that test is supposed to posses predict validity.

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Prediction is made authentic by correlating the test results with some other external criterion that has already been proved to authentically predict efficiency in the job concerned.

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If the test scores are found to be highly correlated with the external criterion the test also will be adjudged as valid.

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Because of this external dependence on the external criterion for establishing the validity, it is also called criterion related validity.

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Since this procedure involves the use of statistical procedures for processing empirical data gathered, this type of validity is also called empirical validity or statistical validity .

Concurrent validity:

Concurrent validity It is also an empirical validity like predictive validity.

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In the case of predictive validity the result is correlated with some external criterion, the validity of which is already established. But in the results are compared with some other measure of the same phenomenon, obtained simultaneously.

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For example, a test is administered to a set of examinees and the same aspect is simultaneously measured by a set of evaluators by using rating scale or observation schedules. High correlation between the two sets of scores gathered simultaneously, establishes the validity of the test, which is known as concurrent validity.

Congruent validity:

Congruent validity It is another type of empirical validity. In this case also correlation of two sets of scores is the index of validity.

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Here the test scores are compared with the scores obtained by administering a similar tool of the sake test content, already existing and known to posses validity.

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Since the congruence between the scores obtained from these two similar tests is the basis of establishing validity, it is called congruence validity.

Construct validity:

Construct validity There are situations in which we have to measure some Psychological phenomena which are not observable or measurable, like sociability , integrity etc

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In such situations the experimenter has to operationally define such traits by associating them with certain observable behaviours that might project/ represent that trait.

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Here the trait (for eg; Sociability) is associated with something constructed by the experimenter to represent the traits, it is called a ‘construct’

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Such a test is critically examined by asking questions how well the test scores corresponds to the construct and this type of validity is called construct validity

Factorial validity:

Factorial validity In all the type of validity assessment, the collected data is correlated with scores of a single external criterion.

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But in some times correlation between the scores of the test and the factors common to a group of tests may be determined by using more sophisticated statistical techniques like factorial analysis Such validity is called factorial validity.

3.Reliability:

3.Reliability Reliability of a test indicates the degree of consistency and accuracy with which it measures what if has been intended to measure.

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A test has been administered to a group school students and their scores were collected.

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Without giving opportunity for improvement, the same test is administered after a brief span of time. If there is consistency in the score, then that test is said to be reliable.

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i.e, The first rank holder becomes the first rank holder in the second test tooooooooooo.

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Reliability and validity are related

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But Reliability may not always ensure validity.

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The test may yield consistent score, but it may not measure what we intended to measure.

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It can be compared with a false balance

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A false balance measures an object of 5 k.g as 7 k.g The same balance after any number of times may yield the same score

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A test with high validity has to be reliable also

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There are different methods to determine reliability

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Test-retest method Split half method Equivalent form method

Test-retest method :

Test-retest method Same test is administered to same group of students after a short interval of time Correlation of the two test scores are tabulated High correlation indicates reliability

Split half method :

Split half method Here the test is divided into two equal halves with a belief that the two halves are more or less identical. The two half tests are administered to a large number of pupils

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The correlation between the two sets of half tests were found out High correlation indicates reliability

Equivalent form method:

Equivalent form method In this the test cores are compared with the results of a ‘parallel form’ of test prepared and administered by the examiner to the same group of students. High correlation indicates reliability

4.Discriminating power:

4.Discriminating power A test should be able to discriminate the students in terms of their levels of achievement in the phenomena meassured.

5.Practicability:

5.Practicability A test , even though it satisfies all the above criteria may be useless, if it is not practically feasible in terms of time, effort, finance etc

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