TAS in ChemistryTAS in Chemistry

(AL & ASL Chemistry Practical)(AL & ASL Chemistry Practical)

EDB & HKEAAEDB & HKEAA 18 October 200718 October 2007

ProgrammeProgramme 2:15 Registration2:15 Registration 2:30 Learning and Teaching of TAS2:30 Learning and Teaching of TAS Mr WH FONG, EDBMr WH FONG, EDB 3:00 Assessment Aspects of TAS3:00 Assessment Aspects of TAS Mr CW Pau, HKEAAMr CW Pau, HKEAA 3:30 Break 3:30 Break 3:45 Making Assessment 3:45 Making Assessment Mr WH FONG, EDB and Mr CW PAU, HKEAAMr WH FONG, EDB and Mr CW PAU, HKEAA 4:15 Experience Sharing 4:15 Experience Sharing Mr KB NG, Fukien Secondary School (Siu Sai Wan)Mr KB NG, Fukien Secondary School (Siu Sai Wan) 5:00 Questions and Answers5:00 Questions and Answers

Learning & Teaching in Learning & Teaching in TASTAS

Improve Learning through Improve Learning through AssessmentAssessment

Key factors identified by research:Key factors identified by research: the provision of the provision of effective feedbackeffective feedback to pupils; to pupils; the the active involvementactive involvement of pupils in their own of pupils in their own

learning;learning; adjusting teachingadjusting teaching to take account of the results to take account of the results

of assessment;of assessment; a recognition of the profound influence assessment a recognition of the profound influence assessment

has on the has on the motivationmotivation and and self-esteemself-esteem of pupils, of pupils, both of which are crucial influences on learning;both of which are crucial influences on learning;

the need for pupils to be able to the need for pupils to be able to assess assess themselvesthemselves and and understand how to improveunderstand how to improve..

Assessment for Learning: Beyond the Black BoxAssessment for Learning: Beyond the Black BoxAssessment Reform Group, UKAssessment Reform Group, UK

Why TAS?Why TAS?

Limitations of practical examinationsLimitations of practical examinations Success depends on the methodical use of a limited nSuccess depends on the methodical use of a limited n

umber of well-practised skills.umber of well-practised skills. Practical work in schools is usually geared to the natuPractical work in schools is usually geared to the natu

re of the practical examination, and hence may be limire of the practical examination, and hence may be limited in scope.ted in scope.

The full range of practical objectives is not tested.The full range of practical objectives is not tested. A once-only examination may not measure true ability.A once-only examination may not measure true ability. Teachers are not involved in the assessment procedurTeachers are not involved in the assessment procedur

e.e. The examination does not provide feedback to the stuThe examination does not provide feedback to the stu

dents, and thus has very little educational value.dents, and thus has very little educational value.

Why TAS?Why TAS?

Advantages of TASAdvantages of TAS Educational objectives are more directly and Educational objectives are more directly and

efficiently achieved by the necessary laboratory efficiently achieved by the necessary laboratory experiences and their associated assessments, experiences and their associated assessments, through a better link between theory and practical through a better link between theory and practical work, and by encouraging a greater diversity in work, and by encouraging a greater diversity in experimentation.experimentation.

Examination pressures are reduced.Examination pressures are reduced. It is possible to assess the full range of practical It is possible to assess the full range of practical

abilities.abilities. It provides frequent feedback to students.It provides frequent feedback to students. It increases the professionalism and experience of It increases the professionalism and experience of

teachers.teachers.

Purpose of AssessmentPurpose of Assessment

Assessment for Learning Assessment for Learning 促進學習的評估促進學習的評估Provide information about the progress of studeProvide information about the progress of stude

nts in relation to knowledge and understanding, nts in relation to knowledge and understanding, and various skills and various skills (continuous assessment)(continuous assessment)

Identify where emphasis needs to be made to thIdentify where emphasis needs to be made to the next stage of learninge next stage of learning (feedback) (feedback)

Learning

Teaching

Assessment

Practical Skills Required / Optional in TAS?Practical Skills Required / Optional in TAS?

1.1. Collection of gasesCollection of gases2.2. CrystallisationCrystallisation3.3. Determination of melting and boiling pointsDetermination of melting and boiling points4.4. Distillation and refluxDistillation and reflux5.5. FiltrationFiltration6.6. Handling of colorimeter, pH meter and dataloggiHandling of colorimeter, pH meter and dataloggi

ng systemng system7.7. Flame testFlame test8.8. Handling of simple electrical devicesHandling of simple electrical devices9.9. Liquid-liquid extractionLiquid-liquid extraction10.10. Simple chromatographySimple chromatography11.11. Use of electronic balanceUse of electronic balance

Practical Activities Required / Optional in Practical Activities Required / Optional in TAS?TAS?

1.1. Students have to do a pre-laboratory quiz on Students have to do a pre-laboratory quiz on theory and procedure.theory and procedure.

2.2. Students have to do a risk assessment before Students have to do a risk assessment before they can start their own experiment.they can start their own experiment.

3.3. Students have to planning one or two Students have to planning one or two experiments, in TAS by writing formal experiments, in TAS by writing formal proposalsproposals

4.4. Students have to carry out one preparative Students have to carry out one preparative experiment.experiment.

5.5. Students have to write five detailed reports.Students have to write five detailed reports.

6.6. Students have to present experimental Students have to present experimental findings orally in class, and in a written form.findings orally in class, and in a written form.

Learning, Teaching and Learning, Teaching and AssessmentAssessment

Which goes first?Which goes first? Learning, Teaching and AssessmentLearning, Teaching and Assessment

Learning / teaching goes before assessmentLearning / teaching goes before assessment provide provide sufficient instructionssufficient instructions and and practicepractice relate practical to theoryrelate practical to theory arrange practical as and when appropriatearrange practical as and when appropriate provide provide feedbackfeedback for learning for learning

e.g post hoc discussions on experimental results, e.g post hoc discussions on experimental results, procedures, sources of error, etc.procedures, sources of error, etc.

TAS should be deployed for learning and TAS should be deployed for learning and teaching as well as assessment.teaching as well as assessment.

Teacher Assessment Teacher Assessment SchemeScheme

CW PAU, HKEAACW PAU, HKEAA

Break for 15 minutesBreak for 15 minutes

MakingMaking AssessmentAssessment

Criteria in Assessing Area A Criteria in Assessing Area A Manipulative and observation skills, general bench performanceManipulative and observation skills, general bench performance

1.1. Methodical Working Methodical Working 有條不紊的工作有條不紊的工作 correct sequence of operations, efficient use of correct sequence of operations, efficient use of

time, etc.time, etc.2.2. Experimental Technique Experimental Technique 實驗技巧實驗技巧

correct & safe handling of apparatus & chemiccorrect & safe handling of apparatus & chemicals, and carrying out operations als, and carrying out operations (observe students directly or based on compar(observe students directly or based on comparison with target values)ison with target values)

Criteria in Assessing Area A Criteria in Assessing Area A Manipulative and observation skills, general bench performanceManipulative and observation skills, general bench performance

3.3. Skills in ObservationSkills in Observation read scales on instrument to the correct degree of accread scales on instrument to the correct degree of acc

uracyuracy correct observations correct observations (dichotomous judgement)(dichotomous judgement) recognise relevant and irrelevant observationsrecognise relevant and irrelevant observations use a control to tell whether a change has occurred use a control to tell whether a change has occurred (or(or

al questions/written record)al questions/written record)

4.4. Manual dexterityManual dexterity手法熟練程度手法熟練程度 5.5. OrderlinessOrderliness

Criteria for Assessing Area ACriteria for Assessing Area A 5 major areas5 major areas

Operation of a single piece of apparatusOperation of a single piece of apparatus Carrying out experimental proceduresCarrying out experimental procedures Reading and measurements of different instruments / aReading and measurements of different instruments / a

pparatuspparatus Observational skillsObservational skills General bench performanceGeneral bench performance

depends on the experimental situations depends on the experimental situations (e.g. Acid based titration, kinetics experiment and (e.g. Acid based titration, kinetics experiment and preparative experiment are all very different in natpreparative experiment are all very different in nature and involve quite different skills, hence differeure and involve quite different skills, hence different assessment criteria should be ued)nt assessment criteria should be ued)

Example 1: Acid-base TitrationExample 1: Acid-base Titration

Marks may be allocated by taking into account of the following:Marks may be allocated by taking into account of the following: Rinses out burette taking care to rinse jetRinses out burette taking care to rinse jet Clamps burette verticallyClamps burette vertically Fills jet of burette up before starting titrationFills jet of burette up before starting titration Uses pipette filler correctlyUses pipette filler correctly Pipettes exactly 25 cmPipettes exactly 25 cm33 of dilute sodium hydroxide of dilute sodium hydroxide Transfers exactly 25 cmTransfers exactly 25 cm33 of dilute sodium hydroxide to conical flask wit of dilute sodium hydroxide to conical flask wit

hout spillagehout spillage Adds dilute sulphuric acid in suitable amounts from buretteAdds dilute sulphuric acid in suitable amounts from burette Continually swirls the flask during the addition of the acidContinually swirls the flask during the addition of the acid Works safelyWorks safely Works tidilyWorks tidily

(Earl & Wilford, Practical Assessment in Advanced Chemistry)(Earl & Wilford, Practical Assessment in Advanced Chemistry)

Example 2: Comparison of the rateExample 2: Comparison of the rates of hydrolysis of haloalkaness of hydrolysis of haloalkanes

Experiment Instructions:Experiment Instructions: Devise a small scale experiment to compare the rates of hyDevise a small scale experiment to compare the rates of hy

drolysis of the bromoalkanes given.drolysis of the bromoalkanes given. Write a brief plan of the experiment you intend to carry out Write a brief plan of the experiment you intend to carry out

and hand this to your teacher. and hand this to your teacher. Carry out the experiment and using the evidence you obtaiCarry out the experiment and using the evidence you obtai

n place the three compounds in order of increasing rate of n place the three compounds in order of increasing rate of reaction. reaction.

At the conclusion of your experiment note any modificatioAt the conclusion of your experiment note any modifications you made while carrying it out and hand these to your tns you made while carrying it out and hand these to your teacher along with your derived order of reaction.eacher along with your derived order of reaction.

(Earl & Wilford, Practical Assessment in Advanced Chemistry)(Earl & Wilford, Practical Assessment in Advanced Chemistry)

Example 2: Comparison of the rateExample 2: Comparison of the rates of hydrolysis of haloalkaness of hydrolysis of haloalkanes

Assessment Criteria:Assessment Criteria: Eye protectionEye protection Ethanol is used as a common solventEthanol is used as a common solvent Equal quantities of ethanol, haloalkanes, silver nitrate sEqual quantities of ethanol, haloalkanes, silver nitrate s

olutionolution Correct order of addition of reagentsCorrect order of addition of reagents Time from first addition of silver nitrate solution or haloTime from first addition of silver nitrate solution or halo

alkanealkane Time for first precipitate to appearTime for first precipitate to appear Correct relative order of hydrolysisCorrect relative order of hydrolysis Suitable modificationsSuitable modifications

Criteria for Assessing Area BCriteria for Assessing Area BPresentation of data, interpretation of results, planning of exptsPresentation of data, interpretation of results, planning of expts

1.1. Accurate recording of observationsAccurate recording of observations

2.2. Present results properly and systematically Present results properly and systematically

3.3. Use correct units and appropriate no. of sig. fig.Use correct units and appropriate no. of sig. fig.

4.4. Understand principles; efficient calculations; & Understand principles; efficient calculations; & aware of sources of errors in quantitative workaware of sources of errors in quantitative work

5.5. Recognise the reactions involved & draw Recognise the reactions involved & draw relevant conclusions in qualitative workrelevant conclusions in qualitative work

6.6. Student’s ability to plan and carry out Student’s ability to plan and carry out experimentexperiment

Assessing Area BAssessing Area BPresentation of data, interpretation of results, planning of exptsPresentation of data, interpretation of results, planning of expts

Assessed byAssessed by written reports, questioning, pre-lab quiz, post-lab written reports, questioning, pre-lab quiz, post-lab

quiz etc.quiz etc. Train students to organise and present their Train students to organise and present their

ideas in a logical and systematic mannerideas in a logical and systematic manner Students’ own words and reflect their Students’ own words and reflect their

understandingunderstanding Vary regularly the experiments like using Vary regularly the experiments like using

different methods, samples to be tested, different methods, samples to be tested, concentrations of solutions, indicators, etc. in concentrations of solutions, indicators, etc. in the lab manual to avoid plagiarismthe lab manual to avoid plagiarism

FeedbackFeedback grades/marks/comments, helps students know their grades/marks/comments, helps students know their

learning progresslearning progress

Assessment Activity: Area BAssessment Activity: Area B

CriteriaCriteria WeightingWeighting ScoreScore

Clear account, proper use of chemical Clear account, proper use of chemical nomenclature & terminology, accurate nomenclature & terminology, accurate spelling, punctuation and grammar spelling, punctuation and grammar

22

Correct & efficient calculationsCorrect & efficient calculations 33

Appreciation of data and major source of Appreciation of data and major source of errorserrors 22

Satisfactory answers to discussion questionsSatisfactory answers to discussion questions 22

Draw valid conclusion by applying knowledge Draw valid conclusion by applying knowledge and understanding of Chemistryand understanding of Chemistry 11

1010

Allocation of marksAllocation of marks

1.1. By a scheme of markingBy a scheme of marking

2.2. By impression of the students’ By impression of the students’ work on a particular operationwork on a particular operation

3.3. By overall impression over a By overall impression over a longer period of observation, longer period of observation, for a particular areafor a particular area

Some Remarks on AssessmentSome Remarks on AssessmentMarking scheme vs overall impressionMarking scheme vs overall impression

Be objective and unbiasedBe objective and unbiasedPrioritize skills to be assessedPrioritize skills to be assessedIndependent assessment of different skillsIndependent assessment of different skillsCross check with general descriptor / criteria Cross check with general descriptor / criteria Professional judgementProfessional judgement

Better for teachers to develop their own set of Better for teachers to develop their own set of assessment criteria (teacher professionalism)assessment criteria (teacher professionalism)

Assessment GridAssessment Grid for recording of assessment for recording of assessment results for a number of students in an assessresults for a number of students in an assessment occasionment occasion

From Novice to ExpertFrom Novice to Expert

Difficulty in Awarding MarksDifficulty in Awarding Marks

Q Some new teachers lack confidence in awarding a Some new teachers lack confidence in awarding a reasonable spread of marks and experience undue reasonable spread of marks and experience undue anxiety towards possible discrepancy in assessed anxiety towards possible discrepancy in assessed marks across schools.marks across schools.

A The essence of awarding marks is that teachers The essence of awarding marks is that teachers should be able to give a reasonable spread of marks, should be able to give a reasonable spread of marks, and arrange the students in a proper rank order. and arrange the students in a proper rank order.

A Teachers need not worry about the discrepancy in the Teachers need not worry about the discrepancy in the assessment marks across schools, as this can largely assessment marks across schools, as this can largely be taken care of by the moderation procedure. be taken care of by the moderation procedure.

Instant Lab ReportInstant Lab Report Post lab reports - focus students’ attention on producing Post lab reports - focus students’ attention on producing

good finished reportsgood finished reports Reports at the end of practicalReports at the end of practical

students are likely to work faster, try to make more sense of what tstudents are likely to work faster, try to make more sense of what they are doing, make more observations and record them in better hey are doing, make more observations and record them in better organised notes, and take more care when recording data, pick up organised notes, and take more care when recording data, pick up obvious errors, time to do the work again and correct itobvious errors, time to do the work again and correct it

Adjust the assessment criteria so that full recording of procAdjust the assessment criteria so that full recording of procedures and results will carry more weight than neatnessedures and results will carry more weight than neatness

Free students afterwards to do something more constructiFree students afterwards to do something more constructiveve

More reliable assessment resultsMore reliable assessment results Frequency?Frequency?

(Habeshaw et al, Interesting Ways to Assess Your Students)(Habeshaw et al, Interesting Ways to Assess Your Students)

Planning ExperimentPlanning ExperimentExperiments: not just doing; should involve Experiments: not just doing; should involve

thinking (stimulate and challenge pupils)thinking (stimulate and challenge pupils)Students should try to understand the Students should try to understand the

relations between evidence gathered and relations between evidence gathered and relevant theory (facilitation provided)relevant theory (facilitation provided)

Cognitive skills: Cognitive skills: Recall & Understanding (explain)Recall & Understanding (explain)Higher Skills (analysis, synthesis & evaluation)Higher Skills (analysis, synthesis & evaluation)

Example: Example: Decomposition of NaHCODecomposition of NaHCO33

Incorporating Inquiry into Incorporating Inquiry into ExperimentsExperiments

Inquiry - an active engaging process that mimics the Inquiry - an active engaging process that mimics the work done by actual scientists (NSTA)work done by actual scientists (NSTA)

Choose experiments that Choose experiments that address simple conceptsaddress simple concepts can be completed using familiar equipmentcan be completed using familiar equipment can be safely conducted e.g. microscalecan be safely conducted e.g. microscale where the data can be pooled by the class and where the data can be pooled by the class and

leads to final results leads to final results Require students to design some or all of the Require students to design some or all of the

procedures (ownership and motivation): procedures (ownership and motivation): autonomyautonomy Increase the opportunities for students to think about Increase the opportunities for students to think about

the data they should collect and their presentationthe data they should collect and their presentation

Sources of Inquiry-based Sources of Inquiry-based ExperimentsExperiments

Exemplar Individual Investigations, Exemplar Individual Investigations, Salters Advanced Chemistry Salters Advanced Chemistry ((http://www.york.ac.uk/org/seg/salters/chemistry/investigation/investigations.htmhttp://www.york.ac.uk/org/seg/salters/chemistry/investigation/investigations.htm))

Inquiry-based Experiments in ChemistryInquiry-based Experiments in Chemistry Calculating Heat of SolutionCalculating Heat of Solution Identifying Unknown SolutionsIdentifying Unknown Solutions Brown versus White EggshellsBrown versus White Eggshells Effect of Temp on the Rate of a Clock ReactionEffect of Temp on the Rate of a Clock Reaction

Creative Problem Solving in ChemistryCreative Problem Solving in Chemistry A Black SolidA Black Solid (C & CuO) (C & CuO) Making Copper (from Cu(NOMaking Copper (from Cu(NO33))22))

TAS Project WorkTAS Project Work

Project-work:Project-work:Practical-work basedPractical-work basedInvolves planning, performing and presenting in a Involves planning, performing and presenting in a

written formwritten formEquivalent to one “A” and one “B”Equivalent to one “A” and one “B”

Open-ended vs Guided Project: A continuumOpen-ended vs Guided Project: A continuumGroup project: OKGroup project: OKTry out of TAS project work and be prepared fTry out of TAS project work and be prepared f

or NSS Investigative Studyor NSS Investigative Study

Operating TASOperating TAS How much should students be informed?How much should students be informed? Application for operation of new course (via REO) and Application for operation of new course (via REO) and

11stst participation in public examination (via HKEAA) participation in public examination (via HKEAA) Laboratory facilities and equipmentLaboratory facilities and equipment Choosing experimentsChoosing experiments

Syllabus suggestions, TAS requirementsSyllabus suggestions, TAS requirements Educational value, safety, availability of chemicals & equipmenEducational value, safety, availability of chemicals & equipmen

t, teaching time, etc.t, teaching time, etc. Variety, Cook-book or Inquiry basedVariety, Cook-book or Inquiry based

ArrangementsArrangements Tryout of expts, coordination with LTs, oral and written instructTryout of expts, coordination with LTs, oral and written instruct

ions to students, distribution of chemicals & equipment, laboraions to students, distribution of chemicals & equipment, laboratory reports, etc.tory reports, etc.

Students with physical disabilitiesStudents with physical disabilities

Resource Materials for TASResource Materials for TAS

Practical Chemistry ResourcesPractical Chemistry Resources Exemplars of Learning & Teaching Activities for Sixth Form ChemistrExemplars of Learning & Teaching Activities for Sixth Form Chemistr

y Curriculum (http://resources.edb.gov.hk/~science/chem.htm)y Curriculum (http://resources.edb.gov.hk/~science/chem.htm) Resource Book for Sixth-form Practical Chemistry, CUHK (http://wwResource Book for Sixth-form Practical Chemistry, CUHK (http://ww

w.chem.cuhk.edu.hk/ssc.htm)w.chem.cuhk.edu.hk/ssc.htm) TAS Corner (http://www.edb.gov.hk/cd/sc)TAS Corner (http://www.edb.gov.hk/cd/sc)

高級程度化學實驗資料冊高級程度化學實驗資料冊 Reference Books (Adv Practical Chem, NAS, Classic Chem Expts, IReference Books (Adv Practical Chem, NAS, Classic Chem Expts, I

LPACs etc)LPACs etc) Internet Resources (e.g. Dr David Brook’s website, Nuffield’s websiteInternet Resources (e.g. Dr David Brook’s website, Nuffield’s website

s)s) Datalogging expts, Diocesan Girls’ SchoolDatalogging expts, Diocesan Girls’ School

(http://www.dgs.edu.hk/QEF_Sc/Chem/experiments.htm)(http://www.dgs.edu.hk/QEF_Sc/Chem/experiments.htm) Journals Journals

Chem ReviewChem Review Chem 13 News (Chem 13 News (http://sciborg.uwaterloo.ca/chem13news/index.htmlhttp://sciborg.uwaterloo.ca/chem13news/index.html)) Education in ChemistryEducation in Chemistry 化學教學化學教學

http://resources.edb.gov.hk/cd/scienchttp://resources.edb.gov.hk/cd/science/chemistry/TAS_corner/htmle/chemistry/TAS_corner/html

TAS CornerTAS Corner

Videos on Practical ChemistryVideos on Practical Chemistry

Demonstrate a new technique during lab Demonstrate a new technique during lab classclass

As a resource for students in pre-lab As a resource for students in pre-lab assignmentsassignments

As a review of a specific technical procedureAs a review of a specific technical procedure Quality assurance of laboratory techniquesQuality assurance of laboratory techniques http://cd.edb.gov.hk/sci/chemistry/tas/videos.htmhttp://cd.edb.gov.hk/sci/chemistry/tas/videos.htm

(ETC and CUHK)(ETC and CUHK)

Microscale Chemistry ExptsMicroscale Chemistry Expts R. G. Silberman & L. T. Eubanks. R. G. Silberman & L. T. Eubanks.

(1996). (1996). ACS Small-scale LaboratoACS Small-scale Laboratory Assessment Activitiesry Assessment Activities. ACS.. ACS.

Microscale equipment and methMicroscale equipment and methodsods reduce time and expense reduce time and expense become possible to develop activitibecome possible to develop activiti

es that test a students’ “laboratoes that test a students’ “laboratory thinking skills” and use problery thinking skills” and use problems posed in the laboratory as true ms posed in the laboratory as true assessment toolsassessment tools

Thank you!Thank you!