DESIGNING INSTRUMENTS FOR MEASURING STUDENTS’ EDUCATIONAL OUTCOMES: THE NABTEB APPROACH By T.A. Aworefa Ag. Head, NABTEB Lagos Regional Office Lagos, Nigeria Abstract The Focus of this paper is on public examinations and mode of assessment with particular reference to NABTEB NTC/NBC/ANTC/ANBC Examinations. The paper starts by defining instruments as well as standardized measuring devices, appropriate to a given evaluation. It further explains the steps good test developers must follow conventionally, in constructing test items in order to measure effectively and accurately what testees have learnt to do, thereby indicating appropriately, the degree of success in their past learning activities. The paper further discusses the instruments and techniques used by NABTEB in assessing students' educational attainment in technical/business education programmes, under the following modes of assessment: traditional paper- pencil-tests, assessment of psychomotor and affective areas of project/practical works. In conclusion, the paper calls on those involved in the design and use of measuring instruments in the conduct of public examinations, to be security conscious as most important administrative decisions depend on the information gathered through them. 1.0. INTRODUCTION Variables, teachers and psychologists assess formally or informally include educational attainments, intelligence, aptitude, personality and character. Assessment in an educational setting, meant to describe the progress of the learners, the appropriateness of the curriculum and the effectiveness of methodology, can be done with varying degrees of objectivity. Broadly speaking, this consists giving all the relevant evidence its due weight and particularly, not being conspicuously influenced by selfishness or purely personal biases. This is why psychologists accept that in developing any measuring instrument, it is important to ask these questions. - Is the instrument valid? i.e. does it really measure what it claims to measure? Or is the instrument providing information that is relevant to the decision that is to be made? - Is the instrument reliable? i.e. is it an accurate, consistent and stable measuring instrument? i.e. does it consistently measure whatever it measures? With these questions at the back of the mind and other relevant factors like convenience, appropriateness, usability, storability and interpretability of a measuring instrument, whatever decisions taken as a result of information collected from the use of it is regarded as being objective. 2.0 CONCEPT OF INSTRUMENTS Instruments are selected or developed and well standardized measuring devices, appropriate to a given evaluation (Adewunmi, 1988). Instruments can be developed in form of, tests, interviews, observations, projects, questionnaires, inventory and rating scale etc. Tests are major instruments used in the measure of students’ levels of knowledge, skills and performance in any teaching-learning situation. Daramola (1990) viewed tests as standardized or non- standardized measures of an individual’s response to a systematic sample of stimuli or behaviour from which inferences about the general behaviour can be made. He further explained that: Tests could be either teacher- made tests or standardized tests or both and could take the form of oral or written tests and essay tests or objective tests as the case may be. Tests in public examinations are designed to measure students’ present level of knowledge, skills or performance and to also elicit information on what a student has learnt to do thereby indicating the degree of success in some past learning activities. From the foregoing comments, it should be noted that public examinations such as Primary School Leaving Certificate Examinations, West African School certificate Examinations (SSCE), Degree/NCE Examinations, National Examinations Council (NECO) and National Business & Technical Examinations Board (NABTEB) NTC/NBC/ANTC/ANBC. Examinations, held after students have undergone some training on specified curriculum, adopt the use of tests in the measure of students’ educational outcomes. 2.1 FUNCTIONS OF MEASURING INSTRUMENTS Osunde (2003) asserted that the central purpose of measuring instruments is to improve the process of learning and instruction. He said they are of immense help in a teaching– learning situation. The following are the roles they play: - Periodic appraisal of the level of achievement of students in the various school subjects - Identification or diagnosis of learning difficulties individual students or the class in general are facing. - Guidance and counselling of the students in the areas of educational and vocational decisions, personal and social adjustment problems. - School administrators can pass judgement as to the degree to which the schools’ objectives are being achieved. The identification of strengths and weaknesses in the school’s educational programme and the effectiveness of instructional strategies and materials are possible with data collected through measuring instruments. - Reporting of the progress students are making to parents. This could be done through cumulative results sent to parents. 3.0 BASIC STEPS IN THE DESIGN OF INSTRUMENTS FOR MEASURING STUDENTS EDUCATIONAL OUTCOMES A good test must meet some essential criteria in order for it to accurately assess students’ educational outcomes. Systematic and adequate planning is required on the part of Test Developers if they must have good tests that are valid, reliable and useable. A good Test Designer therefore, should note the following major steps in designing a test. - Obtaining a List of Instructional Objectives. The major purpose of constructing and administering a test is to determine the extent to which instructional objectives have been achieved by the students. An instructional objective is simply a statement of expected learning outcome. Therefore, the test constructor should identify the instructional objectives, which is essential in the effort to construct test items. - Outlining the Content to be Covered In order to ensure that a test adequately samples the subject matter included in the instruction, it is essential to make an outline of the content to be covered by the test. The content is the means through which objectives are to be achieved. It is usually made up of the topics and subtopics within the subject. - Preparation of table of Specifications or test Blue-Print A table of specifications should be prepared before test items are written. This is because a test constructor must follow a systematic procedure to arrive at a representative sample of the instructional objectives and the content to be measured. Developing a table of specifications is the most crucial aspect in test preparation. This is because all subsequent decisions such as the form of the test and types of items to be used, follow from the table of specifications. In preparing a table of specifications, it is customary to combine the instructional objective and the content and this will give us essentially, a two dimensional table. Along the horizontal dimension, there is the content and along the vertical dimension, are process objectives. (See Appendix 1 attached). - Writing the Relevant Test Items At this stage, the test constructor writes the test items that measure the sample of students’ behaviour specified in the table of specifications. In writing the test items, the test constructor should take note of the guidelines which are highlighted in the table of specifications. - Item Analysis Until items are administered to a group or sample of students and scored, there is no empirical information about the adequacy of each item of the test or the test as a whole. The construction of valid and reliable test requires consideration o f quantitative information regarding the difficulty and discrimination power of each item. Whatever may be the purpose of a test, whether it is educational or psychological, its adequacy depends on the care with which each item of the test has been selected. The item analysis is usually discussed under: i. Discrimination power of each item and ii. Item difficulty - Printing and administration of the standardized tests to a larger representative sample of students and determination of validity and reliability coefficients. 4.0 THE MANDATE OF NATIONAL BUSINESS AND TECHNICAL EXAMINATIONS BOARD (NABTEB) The National Business and Technical Examinations Board (NABTEB) was established through decree No. 70 (now act No. 70) of 1993 and specifically charged the Board among others, with the conduct of the technical and Business Examinations hitherto handled by the West African Examinations Council (WAEC), namely: - The Royal Society of Arts - City and Guilds of London Institute - The WAEC Technical and Business Examinations, and - The Common Entrance Examination into Federal and State Technical Colleges. By implication, the boundary of its functions is elastic in that it is expected to harmonize the several other Technical and Business Examinations available in the Nigerian market. Included among these proliferated examinations are Pitman Series, OGT, Trade Test, etc. These proliferated Examinations have been absorbed by NABTEB under its various examinations, namely: - National Technical Certificate (NTC) - National Business Certificate (NBC) - Advanced National Business Certificate (ANBC) - Advanced National Technical Certificate (ANTC) - Common Entrance Examination into Federal and State Technical Colleges, and - Modular Trades Certificate Examinations (Newly introduced) 5.0 STRUCTURE OF NABTEB NTC/NBC/ANBC EXAMINATIONS The main features of NABTEB NBC/NTC/ANBC/ANTC examinations are that: - The NTC/NBC replaced the WAEC Technical and WAEC Business certificates. - The NTC/NBC Examinations are based on the NBTE Modular Syllabuses and the examinations are at par with SSCE. - The NTC/NBC holder will not only have a vocational trade but will have sufficient education to assure upward mobility (admissibility into polytechnics, colleges of Education and Universities) like his/her SSC holder counterpart – a feature which was lacking in the old arrangement. - The advanced versions of the examinations i.e. ANBC and ANTC will be administered to candidates after a minimum of one year industrial experience before being admitted into the program as stipulated b y the NBTE modular curricula. 6.0 MODES OF NABTEB EXAMINATIONS Most of our public Examinations are known to be Norm-referenced in nature because their major concern had been the classification and comparison of candidates. This is no longer tenable especially when it is considered that the nature of the curriculum and instructional procedures employed in an educational system are greatly influenced by the ideology of a nation. A nation in transition, like Nigeria, whose ideology is that of changing The society for the better, providing equal access to knowledge and building an egalitarian society, usually emphasizes socially relevant curriculum, stressing vocational, scientific, and technological aspects and emphasizing mastery of learning. Such competence-based instructional strategy, requires criterion – reference tests because criterion – reference tests are most useful for measuring the mastery of minimum essentials in an instructional programme. Apart from the use of criterion – referenced type of tests by NABTEB, the nature of subjects examined by the Board dictates that its examinations should maintain a good balance between theory and practical. One of the things that distinguishes students or graduates of Technical Colleges from the roadside mechanics, Tailors, Food Sellers, or Artisans is the fact that they are expected to have some theoretical background of what they are doing rather than the trial-and-error approach of the roadside person. At the same time, they are not just mere theoretical persons, they must be practically competent. NABTEB has therefore modified the traditional mode of examinations and made her examinations more worthwhile and closer to measuring the contents (theory and practice) of Technical and Business Education. For this purpose, NABTEB has adopted the use of a combination of the following measuring instruments. 1. The multiple-choice (objective) tests to make for more coverage of content area. 2. The short-structured tests (of about 25 items) to test. a) verbalization which are known to serve as motor line for the direction of musculations in the process of performing actions in psychomotor skills, and b) principles and skills that may not be conveniently covered by the multiple – choice items and yet cannot be lumped with essay test items. 3. Essay and Mechanical Achievement tests which require candidates to relate, describe and write out their own productions or find out how much of the mechanical ability to which the candidate had been exposed can be recalled, recognized and applied under examination conditions. 4. Evaluation of psychomotor and affective areas of projects/practical works. This involves performance tests where candidates or groups of candidates are assigned various things to construct, repair, manipulate or demonstrate skills acquired especially in their chosen trades within the period of training in the Technical Colleges. 7.0 STRATEGIES FOR ACHIEVING QUALITIES IN THE DESIGN OF MEASURING INSTRUMENTS The development of Essay and practical test items and other skill tests follow the same pattern. However, practical test, a proficiency test of skills in a given trade or profession, tests one’s knowledge, ability and aptitude to do something well. This is why NABTEB places premium on the recruitment of qualified and experienced staff and examiners in handling its examinations. Whoever therefore will be item writers, examiners or verifiers of Trades in NABTEB must be experts in the fields with relevant teaching and industrial experience. This knowledge enables subject officers and commissioned item writers participate effectively in item generation and moderation exercises. 7.1 DESIGN OF NABTEB EXAMINATIONS SYLLABI The NABTEB Examinations syllabi are based on the NBTE Modular curricula, and it has being in existence since the inception of the Board. Notable among the Board’s strategies in the design of its examinations syllabi were numerous workshops and consultative meetings held in April 1994, geared towards transforming the NBTE modular curricula into examinations syllabuses. Each panel involved in the workshop, comprised of one expert from a Technical College, one person who worked on the original NBTE curriculum in the trade, one representative of the industry and one WAEC examiner in the trade. The work of the various panels led to the design of syllabuses in 26 Trades, 5 Trade related (cognate) courses, and 4 General (core) subjects. Concerted efforts have been made by the Board to develop syllabi in more Trades due to popular demands from stakeholders. As at 2005, NABTEB has 34 Trades, 4 Trade related and 6 General Education subjects. Several other consultative meetings were also held with officials of the state Ministries of Education, Principals and Staff of Technical College s and professional bodies. In November, 1994, joint meeting comprising of the representatives of the Federal Ministry of Education and Youth Development, National Board for Technical Education (NBTE), the West African Examinations Council (WAEC), Nationa l Business and Technical examinations Board (NABTEB) and the Association of Principals of Technical Colleges (NAPTECON) was also held to deliberate on the examination syllabi of NABTEB. One of the most interesting aspects of the syllabi is that it has bee n designed and expanded to provide the products of our Technical Colleges with adequate basic academic background, necessary for entry into higher institutions of learning for those that are capable. The NABTEB examination Syllabi has not only removed one of the major drawbacks that frustrated and stagnated the products of the old system but also it, (a) promotes quality Technical/Business education and training in employable skills. (b) provides technical education for those with aptitude and ability to compete with their counterparts in Senior Secondary Schools for placement in higher institutions. (c) Provides for a well balanced and informed person (d) Provides for the first time in the educational system, for individualized study, and (e) Provides for private and part time candidates through inherent flexibility in the modular approach. 7.2 DESIGN OF TABLE OF SPECIFICATIONS FOR ITEM GENERATION NABTEB ensures the use of Table of specifications as guides to all item writers commissioned to generate items. Not only are details of the important areas supplied but also the number and thinking levels of such questions are well spelt out in order to maintain good balance and coverage. (See Appendixes I & II attached) 7.3 EDITING OF TEST ITEMS In the process of editing generated items, subject officers/specialists and commissioned test experts, who are armed with the pre-determined content and objectives as specified in the table of specifications, ensure that - The items adequately cover all the relevant content and objectives - Any item or items looking ambiguous are discarded or replaced. - Basic rules for constructing objective and Essay test items are strictly followed. 7.4 ITEM MODERATION After all the items received from writers have been edited by the subject officers in the various components of trades, they are then compiled into groups for moderation by a committee of not less than four experts in the subject selected from the pool of Examiners working with the Board. The services of Examiners who have worked for years with sister examination Bodies or NABTEB and who have been trained and re-trained over the years are engaged by the Board in the exercise. This method of selection has eliminated and completely removed the biases of higher institutions arising from perceived inadequacies of the past. Most importantly, it has increased the level of confidence of Industries and Higher Institutions in NABTEB. During moderation meetings, the compiled items are critically moderated and amended where necessary including the accompanying Table of Specifications. At this stage, the blue-prints are also critically examined for details such as - Accuracy of dimensions and specifications - Appropriateness of the basis for the level being tested. - Accuracy of time allocated. - The nature of materials and appropriateness - Ensuring compliance with the instructional objectives and coverage. - Ensuring agreement with the opinions of curriculum experts, test construction experts and language experts. - Ensuring compliance with the rules of Item generation (objective and essay items inclusive). 7.5 DESIGN OF MARKING SCHEMES OR GUIDES NABTEB examination answer scripts for essay questions are marked at designated marking venues within the country. The marking schemes are finalized by consensus of a team of Chief Examiners and Team Leaders while consistency of marking is determined through standardized marking of dummy scripts first, before the live scripts are issued. Standardization process does not only facilitate familiarization with the marking scheme, monitoring the consistency in its use but also helps in checking on the competence of the Examiners, thus ensuring validity also. Much effort is expended on vetting of scripts by Chief examiners and Team Leaders. Checkers are also engaged to ensure that candidates are not at undue advantage or disadvantaged positions for quality control. NABTEB provides guidelines for Examiners to scrutinize and detect irregularities and malpractices from candidates’ scripts during marking. This is a means of quality control which amenorates the effects of poor supervision and invigilation thus contributing to assurance of validity, reliability and the integrity of the Examinations. At the end of each marking exercise, it is made mandatory for Chief examiners to write comprehensive reports as feedback information on the standard of the papers, suitability of the marking scheme and other important information on the Examinations. 7.6 EVALUATION OF PSYCHOMOTOR AND AFFECTIVE AREAS OF PROJECT/PRACTICAL WORKS. The types of assessment used by NABTEB in the practical assessment of candidates are product and process Evaluation models. In product evaluation, the finished jobs are marked by the appointed practical Examiners while in process evaluation the presence of the examiner or verifier is required at the centre during the Practical Examinations to see every candidate performs the step by step operation of his tasks and rating the candidate’s performa nce accordingly, on the spot with the aid of practical check lists provided. Some examples of practical TABLE I S/N Trade Assessed by Process Trade Code Trade Assessed by Trade Eval. Product Eval. Code 1. Agric Equipment & 010 * Fabrication and 050 Implementation Welding mechanics works * Mech. Engr. 060 Craft Practice 2. Motor vehicle 020 Printing Craft 360 Mechanics 3. Auto-Electrical Work 030 Graphic Art 380 4. Elec. Install. & Maint. 040 Ladies Garment 330 Practice Making 5. Radio, TV & 070 Men’s Garment 320 Electronics Work Making 6. Instrument Mechanics 110 Textile Trades 37A Work 7. Textile Trades 370 * (Assessed by product and process evaluation). Product and process means of assessing practical work of students provide two important functions: - They focus attention on the specific behavioural or attitudinal pattern of work e.g. honesty, attitude towards wastage or otherwise of materials - They provide a convenient method for recording judgement of observer e.g. perseverance. However, product type of evaluation may be disadvantageous as all processes or procedures are not measured and assessed from the beginning. (see Appendix IV, sample of mark sheet for scoring in process evaluation). 7.7 DESIGN OF CHECKLISTS For an effective assessment of practical skills, NABTEB provides a well designed marking scheme check lists which are sensitive enough to discriminate between the poor, fair, good and excellent candidates. In the process of designing this instrument, mode of evaluating the following tasks are included. - Correct interpretation of drawings. - Selection of appropriate tools - Sequential approach to the tasks - Safety observation - Aesthetic movement and handling of materials, apparatus, tools etc. - Total time spent on each task (see Appendix III for sample) 7.8 STANDARDIZATION OF CHECK LISTS NABTEB organizes practical coordination meetings for the purpose of standardizing practical marking scheme. This involves all practical Examiners who are to be assigned to specific centres during the period of the practical examinations. It is in such meetings that the practical test marking schemes are finalized and adopted for use at the centre during marking. Imandojemu (2001) asserted that the preparation of a good marking scheme checklist is the heart and one of the most important aspect of the test itself. He explained further that practical tests easily lend themselves to subjectivity. This is why every ca re is taken in NABTEB to draw out a marking scheme checklist schedule that is objective. 7.9 SCORE DETERMINATION FOR PRACTICAL WORK PIECE The Practical Examiner will ensure that: - The project is of a life size of the object to be made and not a miniature of it - Upper and Lower limits of dimensions are established Scores are then assigned in the following order: a) Exact dimensions – 4 marks b) Upper limits of dimensions – 3 marks c) Lower Limit of dimensions – 2 marks d) Outside or beyond these two limits - 1 mark 8.0 GRADING SYSTEM NABTEB uses multiple cut-off scores on mastery continuum to identify MASTERY, COMPETENT OR MINIMALLY COMPETENT individuals among the examinees. This is done after the standardization of the aggregate scores on each subject. The master is awarded Distinction, the competent is awarded Credit, while the minimally competent is awarded pass. Thus the 3 – range scale on the mastery continuum with the non- mastery continuum become a 4 – range scale and the grading is based on 8 – point scale for the purpose of reporting performance in Trade subjects as shown in Table II below: TABLE II GRADING SYSTEM FOR TRADE SUBJECTS/COMPONENTS Boundary/Cut-off Grade of standardized Description Letter Grade Number Grade Scores 80 and above 1 75 – 79 Distinction A 2 70 – 74 3 65 – 69 4 60 – 64 Credit C 5 55 – 59 6 50 – 54 Pass P 7 Below 50 Fail F 8 To report performance in General education and Trade-related subjects, NABTEB adopts the usual stannine scores (a 9-Point scale) as indicated in Table III: TABLE III GRADING OF GENERAL EDUCATION, TRADE RELATED & BUSINESS STUDIES SUBJECTS Boundary/Cut-off Grade of standardized Description Letter Grade Number Grade Scores 80 and above 1 75 – 79 Distinction A 2 70 – 74 3 65 – 69 4 60 – 64 Credit C 5 50 – 59 6 45 – 49 7 40 - 44 Pass P 8 Below 40 Fail F 9 9.0 RECOMMENDATIONS ON NABTEB STRATEGIES FOR EFFECTIVE DESIGN AND USE OF INSTRUMENTS Based on the experience of NABTEB in the conduct of public examinations for its teeming stakeholders, the following recommendations have been deduced for effective design and use of its various measuring instruments. conducting research studies on procedures and modes of assessment and using the findings to up date the existing instruments in order to adapt to new demands. Review of examination syllabuses from time to time. Mounting regular training/workshops/seminars and briefing sessions for item writers, moderators, supervisors and examiners to update their knowledge in test construction and improve their performance in scoring of scripts and examination supervision. Inspecting and monitoring on a regular basis the facilities provided for teaching and learning in centres. Applying effective in-built quality control mechanisms in every aspect of the operational procedures i.e. test development, administration and processing of results. 10.0 CONCLUSION NABTEB enjoys remarkable amount of confidence from its stakeholders because of consistency in the adoption of its operational strategies which make the Board highly responsive to the aspirations and expectations of its teeming beneficiaries. In order to sustain this kind of reputation in public examinations in general, more understanding of human assessment is indispensable for people like teachers and psychologists who exercise great influence through the assessment they make and the decisions that are taken in consequence. Assessment, perceived by psychometrists as the sum of techniq ues available for measuring human performance in all dimensions of behaviour has to be handled with great caution as most administrative decisions like placement, selection, classification, prediction certification and others depend on the information gathered through them. All instruments used in this regard must therefore be carefully selected, developed and standardized in order to enable public examinations achieve the desired objectives. REFERENCES Adewunmi, J.A. (1988) Introduction to Educational Research Technique. Ilorin, Gbenle Press. Ahmana, J.S. and Glock, M.D. (1967) Evaluating Pupils Growth: Principles of test Measurement. Bacon Publishing Company. Awanbor, D. (2004) Text of an address delivered during courtesy calls on the Vice Chancellors of selected Universities on the acceptance of NABTEB certificates. Daramola, S.F. (1990) Measurement of Wants. Unpublished book, University of Ilorin, Ilorin. Gayles, C.S. (1977) Issues in the psychological Assessment of Pre-School Children, Journal of school Psychology, 15 (2), pp 129 – 135. Imandoyemu, A.A. (2001) Perspectives in Vocational and Technical Education. (concept, philosophy and Assessment). Maduemezia, M.U (1997) Strategies for achieving Quality in Educational Assessment: WAEC Experience. A paper presented at the 15 th Annual Conference of Association st th for Educational Assessment in Africa (AEAA) 21 – 27 September, 1997. NABTEB (1992) Information Bulletin No. 3 on the conduct of NABTEB Examinations. December 9, 1992 NABTEB (1997) Information Bulletin No. 6 on the grading system for NBC./NTC (ordinary Craft level) March,, 1997. Onwuegbe, O.C., Osunde, A.U. and Ughamadu, K.A. (1991) Measurement and Evaluation in Education. World of books publishers, Benin-City. Olu Aina (1995) The Challenge of Change in Educational Assessment. A paper delivered to Directors of vocational Education and Principals of Technical Colleges in Nigeria. 5th January, 1995. Osunde, A.U. (2003) Assessment of Test Items. Paper presented at the international Association of Educational Assessment. University of Benin Workshop on Measurement and Evaluation, University of Benin, 4 th – 15th August, 2003. APPENDIX I TABLE OF SPECIFICATIONS FOR 062 – (TURNING, MILLING, SHAPING, PLAINING AND SLOTTING) S/N Topics No. of Thinking Level Cumulative Question Total s CME 14 Know- Compreh Appli- A ledge ension cation LATHE WORK Types and working A B C principles of lathe turning machine. Settling lathe machine, the accessories and operations on the lathe machine. 8 2 3 3 Maintenance of lathe machine. B SCREW CUTTING AND TAPER TURNING Calculation of speed, simple and compound gear trains for screw cutting. Methods of taper turning. 6 2 2 2 Calculation of angle and the angular Emo in taper turning derived from tool setting C. WORK HOLDING METHOD Types of work holding equipment on lathe machine. 4 1 1 2 Application of various work holding devices. D. AUTOMATIC AND SPECIAL PURPOSE LATHE The working principles and work plan for a turning job. Mounting accessories and 6 2 2 2 operation. Grinding lathe tools and maintenance. CME 15 PRINCIPLES OF MILLING MACHINE Types and working principles of milling machine. E. Function, tools and constructional details of milling machine. Accessories and working 10 4 3 3 principles of milling machine. Working principles of straddle milling at one setting. Mounting cutters and speed calculation. Maintenance. F. WORK HOLDING DEVICES Indentations, selection and the use of appropriate work holding devices on milling machines. Mounting and setting jobs on milling machines for operations. 6 1 3 2 Performing of milling operations. G. PLANO MILL MACHINE Types and working principles of Plano milling 6 2 2 2 machine. Functions and attachment of Plano milling machine, mounting tools cutters set up for various operations. Performing the required operation on work-piece with specifications. H. SHAPING MACHINE Types and the uses of essential components and accessories. Functions and constructional details of shaping machine. 10 3 3 4 Principles of operation, selection of tools and setting up. Setting and operating the shaper to produce various components with safety precautions. Maintenance of shaping machine. I. CUTTING SPEED AND FEED Explanation of geometry quick return motion and 2 1 1 the calculation of speed and feed. J. PLAINING MACHINE, SPEED AND FEED Types and sizes of plainer Functions and working principles of plaining machines. 8 2 3 3 Tools and accessories. Mounting work, operation and speed Calculation of speed and feed. K. SLOTTING MACHINE Types and uses of slotting machines. Essential components and accessories of slotting machine. Working principles and setting up slotting machine. Explanation of geometry of “Whiteworth” quick return motion and calculation of working speed. Maintenance of slotting 10 2 3 5 machine. Total No. of Items 54 15 18 21 APPENDIX II TURNING, MILLING, SHAPING, PLANNING AND SLOTTING SECTION B – ESSAY S/N Topics No. of Thinking Cumulative Ques- Level Total tions Know- Compreh Appli- ledge ension cation A B C CME 14 LATHE WORK Screw-turning and tape 6 1 3 2 turning. Automatic and special purpose lathe. Work holding methods. CME 15 Principles of milling machine. Work holding device 4 2 2 Plaining & milling machine CME 16 Shaping machine 4 2 2 Cutting speed and feed Plaining machine, speed and feed Slotting machine Total No. of Items 14 1 7 6 APPENDIX III MARKING SCHEME CHECK LIST FOR MECHANICAL ENGINEERING CRAFT PRACTICE 062 – 2 (TURNING, MILLING, PLAINING AND SLOTTING TEST). Paper Code …………… Day ……………………. Date ………………….. NO. SKILLS/TASKS TO BE RATED EXCEL GOO FAIR PO IN PRACTICAL LENT D OR EXAMINATIONS 1. Correct interpretation of Drawing 3 2 1 4 2. Appearance and finish of all surfaces Squareness of all surfaces 3. Accuracy of Linear dimensions 135, 4. 45, 20, 40, 40, 20 and 18 x 4 5. Positional accuracy of all U-cuts 6. Positional accuracy of chamfers 7. Accuracy of diameters 20, 36, 18, 8. 26 and 19 9. Positional accuracy of flats x 4 10. Positional accuracy of 6mm hole 11. Positional accuracy of 10 x 40mm slot Accuracy of M24 x 2 diameter (threaded or not) SCORE RANGE Diameters All diameters within tolerance - 4 outside diameters + 0.01 Off Tolerance - 1 Linear Dime nsions All Linear Measurements within tolerance – 4. Linear dimensions off tolerances are not scored. NOTE Candidates’ score should be converted to 50 marks using the formula: X x 100 N I Where x is the candidate’s total score and N is the maximum obtainable score. (i.e. N = 40) APPENDIX IV MARKSHEET SUPPLEMENTS FOR PRACTICAL OBSERVATION SCHEDULE (CHECK LIST) PAPER CODE ………… DAY ………………. DATE …………………… PAPER TITLE …………………………….. TIME ………………… CENTRE NAME ………………………………. CENTRE CODE ……………. RATING – EX = 4, GOOD = 3, FAIR = 2, POOR = 1 S/N CAND. CAND. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 NO. NAME NOTE:- This is used for scoring candidates in process assessment in combination with the marking scheme check list (Appendix III).
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