introduction of dat

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DIFFERENTIAL APPTITUDE TESTS

(DAT)

By:

Mubashra Hafeez(M.Sc. Applied Psychology)

Dated:

15th Feb, 2012



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Introduction

The original form of DAT were developed in 1947 toprovide an integrated scientific and wellstandardized procedure for measuring the abilities ofboys and girls in Grade 8 through 12 for the purpose

of educational and vocational guidance. The differential aptitude were revised and

re-standardized in 1962 and again in 1972. The1962 revision of test was directed primarily at

making the test easier to administer. The 1972revision retained the earlier changes and in additionsubstantially updated five of eight tests.



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Not Ability But Abilities

Subsequent to the 1920’s there was a growingrecognition of need for measures of many aspectsof mental abilities. The research and theories ofThorndike, Spearman, Thomson and other havemade us increasingly aware that so calledintelligence is not a unitary trait it is composed ofmany abilities which are present in differentindividuals in varying amount.

Till 1920’s there were a lot of tests developed for the

measurement of behavior such as Minnesota Paperform Test, Stenquist’s echanical aptitude testse.t.c.but in 1930’s there were need to develop a testfor measuring the vocational abilities of individuals.



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Definition of Aptitude

The definition of aptitude which Bingham preparedfor Wetern’s dictionary of psychology is an excellentstarting point for elucidation of concept.

Aptitude a condition or a set of characteristicsregarded as symptomatic of an individuals ability toacquire with training some knowledge, skill or set ofresponses such as the ability to speak a language,

to produce music.



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Definition of Aptitude Contd..

A complete appreciation of this definition eliminate anumber of misunderstandings which are prevalent.First there is no assumption of here that aptitudes

are hereditary. The expression born that way isfallacy which skill is heard even among educatedpeople.

Aptitude is the result of interaction of heredity and

environment. An individual is born with certainpotentialities and begins to learn immediately.



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Definition of Aptitude Contd..

A second important feature of definition is that it isextremely broad. It implies that aptitude embracesany characteristic which predisposes to learning

including intelligence, achievement, personality,interest and special skills. It is therefore misleadingto limit the use of term “aptitude” to specializelearning capacities such as those for music orengineering.

The total concept can perhaps be summaries byregarding aptitude as simple a capacity to learn.



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Disadvantages of Assemble Batteries

Each such test has been developed singly and nomatter how sound the individual standardization, therelationship of the test to each other has left much tobe desired statistically and in term of practical

interpretation.

The separate tests in the team may have bedeveloped for particular purposes e.g. guidance,employment or particular level e.g. school, adult or

particular ranges of talent and therefore may not bebest adapted for use within the range of age orschooling of those to be tested.



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Disadvantages of Assemble Batteries

Contd..

As a practical matter, the formats, the administrativeprocedures, the use of answer sheets, the timelimits etc. frequently are not optimum in assembled

batteries.



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Aptitude to be Measured

In 1947, it was necessary to decided what aptitudeshould be measured by the battery. The attemptwas made to include tests in the battery each of

which would be useful in many areas rather than inonly one or two, and each of which would providemeaningful source readily interpretable by informedCounselors and Teachers.

The most important goal was to satisfy the needs ofCounselors and others who must make practicalapplications of test scores.



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Batteries of DAT

Verbal Reasoning.

Numerical Ability.

Abstract Reasoning.

Clerical Speed and Accuracy.

Mechanical Reasoning.

Space Relations. Spelling.

Language Usages



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Principle Governing the Test

Construction

Each should be an independent test.

Because of varied situations in which guidance andpersonal selection take place, it was determined that

each of abilities to be measured should testedseparately. While it is intended that the whole batterybe given for educational and vocational counseling,there are other situations in which only part of battery

is required or desired. Therefore the tests were madeso that they could be given independently.



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Construction Contd.. The Tests should Measure Power.

The purpose of measuring the person’s particularability is usually to discover the level at which he canperform. A mathematician is one who can solvecomplex mathematical problems; a person who canadd two place numbers rapidly and accurately may beskilled clerk, but not necessarily a mathematician. Formost purposes to which tests results contribute the

evaluation of individual’s power in the particular abilityor skills is of primary concern.



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Construction Contd.. The Test Battery should Yield a Profile.

The eight separate scores yielded by DAT areconvertible to percentile ranks and can be plotted aprofile chart to facilitate interpretation. Since thepercentile rank for every test are based on the samepopulation, the points on the profile are comparable.One combination of scores is also offered: VerbalReasoning plus Numerical Ability. This combination

serves the same purpose as would tests of scholasticaptitude and make administration of laterunnecessary.



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Construction Contd.. The Norms should be Adequate.

The Norms are presented separately for bys and girls,to reflect sex differences which appear in some ofabilities measured by tests. Norms are also presentedseparately for fall and spring semesteradministrations.

The Tests Material should be Practical.

The materials for DATs are designed withadministrative convenience in mind e.g. the format ofthe test booklets has changed over the year of

accommodate changing needs.



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Construction Contd.. The Tests should be easy to Administer.

The basic directions for taking each test are printedthe test booklet. They are to be read aloud by theexaminer and silently by the persons being tested.The two governing principles in planning theadministrative features of DAT were that the testsshould be an administrable by teachers or industrialemployment personnel with the minimum of special

training, and that the directions and illustrations shouldbe clear to the persons taking the test. Alternativeform should be available.



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Description of the Eight Tests Verbal Reasoning

Ability to reason with words to understand ideasexpressed in words. Important in academic courses also for job requiring

much written and oral communication and for jobsinvolving a lot of responsibility such as supervisory

position. Numerical Ability

Ability to reason with numbers, to understand andwork with ideas expressed in numbers.

Generally important in school work, especially for

subjects, such as Mathematics, Chemistry, Physicsand Engineering. Useful in such jobs as Engineer, Laboratory

Technician, Shipping Clerk, Carpenter and Statistician



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Description of the Eight Tests Contd..

Abstract Reasoning

Ability to understand ideas that are not presented inwords or numbers, to see relationships among things,such as objects, patterns diagrams, or designs. Usefulin shop drafting and laboratory work, also inmathematics, in electrical or mechanical repair work,and in computer programming.



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Clerical Speed and Accuracy

Quickness and accuracy in comparing and markingsimple letter and number combinations.

Important in paper work in school, in office,laboratories, stores, warehouses, filed or checked.

Sometimes, a low scores on this test combines withhigher scores on the other may actually indicate agreat concern with accuracy not a true lake of ability towork quickly.



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Mechanical Reasoning

Understating of mechanical principles and devices,and of the law of every day physics.

Courses in the physical sciences, technical studies ormanual training shop are easier for those who scorehigh in this test. So are mechanical repair work and avariety of factory and engineering tasks.



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Space Relations

The item type devised for the space relations testrepresent the combination of two previous approachesto measurement of this ability.

Ability to think in three dimensions to picture mentallythe shape size and position of objects when shownonly a picture or pattern.

Drafting, shop courses, some kinds of mathematicsand some art or design courses are among thoserequiring this ability.



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Spelling

An important skill in school And college work, and inmany jobs.

This score is one of the best predictor of how easilyand quickly you can learn typing and short hand.

Language Usage

Ability to distinguish between correct and impropergrammar, punctuation and capitalization.

An excellent predictor of grades in most high schooland college courses.

Well developed language skills are needed in most all jobs requiring a college degree.



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Steps in Administrating the Tests

Introduction

Try to put the students at ease by explaining brieflywhy the tests are being administered.

This tests may be done a day or so in advance. Students should be told not to be discouraged, if some

of the questions are too difficult.

Before each test state in few simple words what the

particular test is about. Concise statement which illustrate the distinct nature

of each of the eight tests appear on the individualreport form and these may be used for this purpose.



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Contd..

Pencils

See that each student should have two soft leadpencils with erasers.

The examiner should have additional pencils on thehand to meet any emergencies before the clericalspeed and accuracy tests, it is especially important tocheck pencils on students’ hands since this is a speed

test.



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Contd..

Answer Sheets and Booklets

Distribute the answer sheets, then test booklets.

Make certain that each students has both answer

sheets before distributing the booklets make thefollowing announcements “Do not Open your booklet until I tell you to do so” .

The examiner should have a copy of test booklet

and answer sheet.



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Contd..

Answer Sheets and Booklets contd..

Examiner should give following instructions to thestudents at the very beginning of test:

“On the line beginning with name at the top of answer sheet, print your name, last name first.Then fill in today’s date”

“Be sure to make a heavy black mark filling the entire circle. Don’t go outside the circle if you make

a mistake erase very carefully” “You must mark all your answers with a lead pencil”

“You will write nothing in the booklet but will markall your answers in the answer sheets”



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Contd..

Reading Directions

The examiner should read the directions aloud, from acopy of the booklet while the student read themsilently.

Each student must understand what he is to do beforebeginning of the test. When the questions have beenanswered, read the final paragraph of directions pagefor the test being given and add the followingsentences:-

“You should keep in mind that you are to mark only one answer to each question, if you mark more than one answer, you cannot receive the credit for that question” .



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Contd..

Timing

When all the directions have been read andthe questions answered, say, in clear voice

“Turn the page and begin” and start timing. At the end of the time say “Stop, please put

down your pencils”



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Contd..

Timings for Each batteries Verbal Reasoning 30 mins

Numerical Ability 30 mins

Abstract Reasoning 25 mins

Clerical Speed & Accuracy Part-I 03 mins

Part-II 03 mins

(The timing for speed test must extremely accurate to thesecond)

Mechanical Reasoning 30 mins Space Relations 25 mins

Spellings 10 mins

Language Usage 25 mins



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Contd..

Subsequent Tests and Collection of Material

When one test has been completed, tell the studentsto turn the directions page for next test to be given inthe booklet.

At the close of each testing session, all answer sheetsand booklets are to be collected.



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Contd..

Testing Log

Immediately following each testing session, theexaminer should prepare a memorandum, givingpertinent information, such as group tested, room,date, proctors, timing, any deviation from regularprocedures and further information which might help ininterpreting the test results.

A good practice is to provide each examiner with a

form which make this recording convenient.



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Scoring Procedure

All answer sheets designed for use with DATs canbe scored either by hand or machine. If answersheets are scored by hand, they must be scoredwith the aid of key design for the form administeredand for the type of answer sheet utilized. The scorefor each test is the number of right answers, there isno correction for guessing.



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Scoring Procedure Contd..

The maximum possible raw scores for each test isgiven below:-

Verbal Reasoning 50

Numerical Ability 40

Abstract Reasoning 50

Clerical Speed & Accuracy 100

Mechanical Reasoning 70

Space Relations 60

Spellings 100

Language Usage 60



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Hand Scoring When scoring is done by hand, it is necessary first to

inspect the answer sheet to determine whether thestudent marked two or more choices for any item. If

two or more choices have been marked, that item itemshould be omitted from scoring.

The most efficient way to handle these multiplemarked items is by drawing a horizontal Red Line through all of the multiple responses to the item.



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When the scorer places the key over the answer sheetthe red marks will show through, and those items arethen easily omitted from the count.

The scorer should make sure that the form marked by

the student on the answer sheet agrees with thatprinted on the scoring key used. The key must becorrectly placed over the answer sheets and thescores record in appropriate places.



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Reliability

Reliability is an important characteristic of any test, and itis critical for the test design in individual guidance.

One of the aim in constructing DAT was accordingly tosecure scores as reliable as possible without exceeding

limits of testing time.

The appropriate way of determining the reliability isthrough alternate form of test.



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Validity

The DAT were designed for practical application incounseling, selection and placement.

Tests used in such situations must have technicallysatisfactory norms and level of reliability, be easy to

administer and straight forwarding format.

In addition to these requirements, however, a testinstrument can be practical value only in so far as it hasbeen shown to be valid in application.



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THANK YOU

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