Seminar on TAS for AL & ASL Chemistry Practical 22 October 2005 - PowerPoint PPT Presentation

seminar on tas for al asl chemistry practical 22 october 2005 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Seminar on TAS for AL & ASL Chemistry Practical 22 October 2005 PowerPoint Presentation
Download Presentation
Seminar on TAS for AL & ASL Chemistry Practical 22 October 2005

play fullscreen
1 / 35
Download Presentation
Seminar on TAS for AL & ASL Chemistry Practical 22 October 2005
Download Presentation

Seminar on TAS for AL & ASL Chemistry Practical 22 October 2005

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Seminar on TASfor AL & ASL Chemistry Practical22 October 2005

  2. Programme 9:00 Registration / Exhibition 9:15 Introduction to Chemistry TAS Dr T M Li, HKEAA 9:45 Learning, Teaching & Assessment of Practical Skills, Assessing Area A, Mr W C HO, EDB 10:45 Break 10:55 Assessing Techniques, Resources on Practical Chemistry Mr W C HO, EDB 11:45 Experience Sharing Mr C K Leung, NTHKY Yuen Long District Sec School Mr KM Chan, TWGHs Mrs Wu York Yu Mem College

  3. Why TAS? • Drawbacks of practical examination(QA & VA) • More relevant and greater variety of expts in TAS • Convey the excitement and wonder of Chemistry through practical work • Reinforce understanding and knowledge of theory • Develop practical and generic skills

  4. Assessment Learning Teaching Purpose of Assessment • Assessment for Learning 促進學習的評估 • Provide information about the progress of students in relation to knowledge, skill and understanding • Identify where emphasis needs to be made to the next stage of learning

  5. Improve Learning through Assessment • Key factors identified by research: • the provision of effective feedback to pupils; • the active involvement of pupils in their own learning; • adjusting teaching to take account of the results of assessment; • a recognition of the profound influence assessment has on the motivation and self-esteem of pupils, both of which are crucial influences on learning; • the need for pupils to be able to assess themselves and understand how to improve. Assessment for Learning: Beyond the Black Box Assessment Reform Group, UK

  6. Teaching vs Assessment • Which goes first? • Teach to learn • teaching goes before assessment • provide sufficient instructions and practice • relate practical to theory • arrange practical as and when appropriate • provide feedback for learning e.g post hoc discussions on experimental results, procedures, etc.

  7. Criteria in Assessing Area A/.. Manipulative and observation skills, general bench performance • Methodical Working 有條不紊的工作 • correct sequence of operations, efficient use of time, etc. • Experimental Technique • correct & safe handling of apparatus & chemicals, and carrying out operations (observe students directly or based on comparison with target values)

  8. Criteria in Assessing Area A/.. Manipulative and observation skills, general bench performance • Skills in Observation • read scales on instrument to the correct degree of accuracy • correct observations (dichotomous judgement) • recognise relevant and irrelevant observations • use a control to tell whether a change has occurred (oral questions/written record) • Manual dexterity手法熟練程度 • Orderliness

  9. Assessment in Practice • Marking scheme • Overall impression (Descriptors), holistic • Be objective and unbiased • Independent assessment of different skills • Professional Judgement • Prioritise skills to be assessed

  10. Making Assessment Criteria /.. • 5 major criteria for Ability Area A • Operation of a single piece of apparatus • Carrying out experimental procedures • Reading and measurements of different instruments / apparatus • Observational skills • General bench performance • depends on the experimental situations (e.g. Analysis of SO2 in Wine)

  11. Acid-base Titration Marks may be allocated by taking into account of the following: • Rinses out burette taking care to rinse jet • Clamps burette vertically • Fills jet of burette up before starting titration • Uses pipette filler correctly • Pipettes exactly 25 cm3 of dilute sodium hydroxide • Transfers exactly 25 cm3 of dilute sodium hydroxide to conical flask without spillage • Adds dilute sulphuric acid in suitable amounts from burette • Continually swirls the flask during the addition of the acid • Works safely • Works tidily (Earl & Wilford, Practical Assessment in Advanced Chemistry)

  12. Making Assessment Criteria • Assessment Activity #1 • Cross check with general descriptor criteria • Better for teachers to develop their own set of assessment criteria to promote teacher professionalism • Assessment Grid for a no. of students in an assessment occasion

  13. Time-out 休息時間

  14. Criteria in Assessing Area B/..Presentation of data, interpretation of results, planning of expts • Accurate recording of observations • Present results properly and systematically • Use correct units and appropriate no. of sig. fig. • Understand principles; efficient calculations; & aware of sources of errors in quantitative work • Recognise the reactions involved & draw relevant conclusions in qualitative work • Student’s ability to plan and carry out experiment

  15. Assessing Area B/..Presentation of data, interpretation of results, planning of expts • Assessed by • written reports, questioning, short quiz etc. • Train students to organise and present their ideas in a logical and systematic manner • Students’ own words and reflect their understanding • Vary regularly the information in the lab manual to avoid plagiarism • Feedback • grades/marks/comments, helps students know their learning progress

  16. What is Practical Work? • Not merely as a practical activity – doing things • Essentially to be about thinking • trying to understand the relations between evidence and theory • stimulate and challenge pupils • Cognitive skills: • Recall • Understanding (explain) • Higher Skills (analysis, synthesis & evaluation) • Example: Heat of Hydration of CuSO4

  17. Comparison of the rates of hydrolysis of haloalkanes Experiment Instructions: • Devise a small scale experiment to compare the rates of hydrolysis of the bromoalkanes given. • Write a brief plan of the experiment you intend to carry out and hand this to your teacher. • Carry out the experiment and using the evidence you obtain place the three compounds in order of increasing rate of reaction. • At the conclusion of your experiment note any modifications you made while carrying it out and hand these to your teacher along with your derived order of reaction. (Earl & Wilford, Practical Assessment in Advanced Chemistry)

  18. Comparison of the rates of hydrolysis of haloalkanes • Assessment Criteria: • Eye protection • Ethanol is used as a common solvent • Equal quantities of ethanol, haloalkanes, silver nitrate solution • Correct order of addition of reagents • Time from first addition of silver nitrate solution or haloalkane • Time for first precipitate to appear • Correct relative order of hydrolysis • Suitable modifications

  19. Incorporating Inquiry into Expts • Choose expts that • address simple concepts • can be completed using familiar equipment • can be safely conducted e.g. microscale • where the data can be pooled by the class and leads to final results • Inquiry - an active engaging process that mimics the work done by actual scientists (NSTA) • Require students to design some or all of the procedures (ownership and motivation): autonomy • Increase the opportunities for students to think about the data they should collect and their presentation

  20. Inquiry-based Experiments • Exemplar Individual Investigations, Salters Advanced Chemistry ( • Inquiry-base Experiments in Chemistry • Calculating Heat of Solution • Identifying Unknown Solutions • Brown versus White Eggshells • Effect of Temp on the Rate of a Clock Reaction • Creative Problem Solving in Chemistry • A Black Solid (C & CuO) • Making Copper (from Cu(NO3)2)

  21. Assement Criteria in UK

  22. Microscale Chemistry Expts • R. G. Silberman & L. T. Eubanks. (1996). ACS Small-scale Laboratory Assessment Activities. ACS. • Microscale equipment and methods • reduce time and expense • become possible to develop activities that test a students’ “laboratory thinking skills” and use problems posed in the laboratory as true assessment tools

  23. Assessing Project Work • Inquiry-based expts, Investigation, Project • Encourage students to learn by exploration • Include designing experiment, investigation and written report • Develop their skills in problem-solving, planning, data handling, organisation and presentation • Guidelines for students; Nuffield tutorials on investigation ( • Criteria in IS: proposal & plan (15%), Process (30%), Report writing & conclusion (30%), Evaluation and reflection (15%), Attitude (10%) • Each project equivalent to a max of 3 expts (1 A & 1 B) • 1 report for each group work, request presentation for assessment B of individual students

  24. Scoring Rubrics to Evaluate Student Inquiry • Define the end product of inquiry e.g. portfolios, research report, laboratory practicals and student demonstrations, student journals, concept maps • Decide criteria and weight: expect tasks, behaviours, and skills and setting standard levels at which students must perform; eliminates or reduces guesswork on students’ part concerning how they will be graded • Decide who will assign the grade e.g. expert judging (supervisor’s sheet), self-evaluation and peer evaluation Lunsford E & Melear C T (2004) Journal of College Science Teaching, Sept, pp.34-38

  25. Rubric for evaluating a research report

  26. Student Self-assessment Forster, M & Master, G (1996) Projects Assessment Resource Kit

  27. Peer Assessment • Student ______________ has contribute to the group’s work in the following ways: Habeshaw, S & Gibbs, G & Habehaw, T (1998) Interesting ways to assess your students

  28. Practical Chemistry Resources • Exemplars of Learning & Teaching Activities for Sixth Form Chemistry Curriculum, • Resource Book for Sixth-form Practical Chemistry, CUHK • TAS Corner ( • 高級程度化學實驗資料冊 • Reference Books (Adv Practical Chem, NAS, Classic Chem Expts, etc) • Internet Resources • Datalogging expts, Diocesan Girls’ School • Journals e.g. Chem Review, Chem 13 News(, Education in Chemistry, 化學教學

  29. Videos on Practical Chemistry • Demonstrate a new technique during lab class • As a resource for students in pre-lab assignments • As a review of a specific technical procedure • Quality assurance of laboratory techniques •

  30. Recurrent Grants for TAS • Purpose • Purchase of chemicals, glassware and consumable items • Minor repair/replacement of advanced level chemistry equipment • Eligible for government, aided and caput schools • Constituent Grants of: • Operating Expenses Block Grant 「營辦開支整筆津貼」for Aided Schools (Adm Circular No. 27/2000 & CM No.161/2005) • Subject and Curriculum Block Grant for Government Schools「官立學校科目及課程整筆津貼」School Finance & Account Circular No.2/2000 • Provisional payment and adjustment • AL: HK$ 2,483 per class per annum (2005/06) • ASL: HK$ 1,621 per class per annum (2005/06) • Split-class Teaching in Sixth Form • Estimates for 2005/06: Applications for Grants : Aided Secondary Schools (CM No. 27/2005)

  31. Operating TAS • How much should students be informed? • Application for operation of new course (via REO) and 1st participation in public examination (via HKEAA) • Laboratory facilities and equipment • Choosing experiments • Syllabus suggestions, TAS requirements • Educational value, safety, availability of chemicals & equipment, teaching time, etc. • Variety, Cook-book or Inquiry based • Arrangements • Tryout of expts, coordination with LTs, oral and written instructions to students, distribution of chemicals & equipment, laboratory reports, etc. • Students with physical disabilities

  32. Instant Lab Report • Post lab reports - focus students’ attention on producing good finished reports • Reports at the end of practical • students are likely to work faster, try to make more sense of what they are doing, make more observations and record them in better organised notes, and take more care when recording data, pick up obvious errors, time to do the work again and correct it • Adjust the assessment criteria so that full recording of procedures and results will carry more weight than neatness • Free students afterwards to do something more constructive (Habeshaw et al, Interesting Ways to Assess Your Students)

  33. Assessment Enhances Learning if it: • Encourages intrinsic motivation • Builds confidence • Gives a sense of ownership and control • Provides detailed feedback constructively • Encourages collaboration between students Prof. Patricia Broadfoot, U of Bristol


  35. Thank you!