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A/AS level Chemistry TAS

Workshop for Teachers

18 October 2007

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Teacher Assessment Scheme

Practical paper of the A/AS level Chemistry Examination

20% of the subject mark Compulsory to all school candidates

(including first-timers and repeaters) Private candidates : either (i) use

previous TAS result , or (ii) take practical exam

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TAS allows: better link between theory and practical work students to experience a wider range of

experimentation the assessment of a full range of practical

abilities reduction in examination pressure teachers to provide frequent feedback to

students increase in teachers’ professionalism

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Requirements of TAS

Lab work should cover different areas and types of experiment

Area : CH, EQ, KI & EN

Type: P, QL and QN

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Requirements of TAS(cont’d)

Number of experiments

A-level 15 experiments in S6

8 experiments in S7

AS-level 13 experiments in 2 years

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Requirements of TAS(cont’d)

Ability area A

Ability area B

Ability area C

Manipulative skills, skills in observation and general bench performance

Presentation of data, interpretation of results, planning of experiments and project work

attitude towards practical chemistry

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Minimum requirement for each candidate

Ability area

No. of Assessment Marks reqd.

S6 S7 Over the two years

A >2 >1 >4

>10B >2 >2 >4

C 1 1 2

A-level (First-timer)

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Minimum requirement for each candidate

Ability area

No. of Assessment Marks reqd.

S6 S7 Over the two years

A >1 >1 >2

>7B >1 >1 >2

C 1 1 2

AS-level (First-timer)

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Repeaters & transferred candidates in TAS

Students who join S7 chemistry classes directly in the year of repetition or transfer.

Ignore all their previous TAS marks or practical examination marks.

Make assessment as follows:A-level : minimum 3A, 3B and 1C

AS-level : minimum 2A, 2B and 1C

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Making assessments

Assess each student sufficiently on each ability.

Not necessary to assess all students on the same day and on the same experiment.

Assess as unobtrusively as possible.

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Making assessments (cont’d) Assess on a 10-point scale:

10-9 very good

8-7 good

6-5 average

4-3 weak

2-1 very weak

(Refer to Appendix III of TAS Handbook.)

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Making assessments (cont’d)

3 ways for allocation of marks:

(i) Mark Scheme

(ii) Impression

(iii) Overall impression over a longer period of time, for a particular area e.g. area C

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Project work in TAS

Not compulsory Involve practical work and experimental

investigation Include:

designing experimentperforming the investigationwriting the report

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Project work in TAS (cont’d)

One project = max. 3 experiments

For each student, each project can be used to assess 1A & 1B only

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Lab reports Language medium used must be the

same as that chosen for the written exam.

Detailed reports:object of expt, chemical principles involved, experimental method, results, interpretation and discussion, conclusion.

First-timers: 4 for AL and 3 for ASL Repeaters: 2 for AL and 1 for ASL All reports should be marked.

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Information about TAS:

Refer to Handbook on the A/AS Chemistry Teacher Assessment Scheme

HKEAA website: www.hkeaa.edu.hk

Enquiry: 36288068 (Ms Tansy Chun) 36288025 (Mr CW Pau)

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Always consult your group coordinators when you have

queries or problems

Reminder

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Common problems reported by coordinators

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(1) Unclear experiment titles

E.g. (i) Project 1

(ii) To prepare a carboxylic acid

Titles entered in the TAS assessment records should be informative and specific.

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(2) Insufficient no. of preparative experiments

Experiments indicated as P are not preparative experiments.

Preparative experiments should involve techniques such as:handling of gases, filtration, crystallization, recrystallisation, distillation, reflux, drying, liquid-liquid extraction, purity control by determining melting point / boiling point.

A minimum of 2 P experiments should be carried out. (TAS Handbook)

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(3) Mark range too narrow / too wide

For each candidate, the mark awarded should reflect the typical standard of the candidate.

For the whole class, the marks awarded should be able to discriminate candidates with different abilities.

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(4) Teacher changes Best to have more than one teacher

familiar with the Scheme Out-going teacher to hand over

his/her work on TAS to new teacher, including:List of experiments and their handoutsRecords of TAS marks awarded to

students e.g. printouts of softwareTAS program, its passwords, and

backup diskettes, if any Inform coordinator of the change

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(5) Mark Adjustment

Rank order of students in a class will be preserved.

Adjusted TAS mean marks calculated from Written Paper mean marks.

TAS marks will be shifted upwards/downwards.

SD of TAS marks will be preserved.

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Skills to be tested in GCE A Level Science Subjects

P – PlanningI – ImplementationA – Analysing Evidence and

Drawing ConclusionsE – Evaluating Evidence and

Procedures

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Questions & Answers