Transcript Inquiry-based Practical Chemistry & its Assessment 探究為本化學實驗的推行及評估 5 Nov 2005

Inquiry-based Practical
Chemistry & its Assessment
探究為本化學實驗的推行及評估
5 Nov 2005
Science Education Section
EDB
Programme
9:00 – 9:15 /
2:00 – 2:15
9:15 – 9:20 /
2:15 – 2:20
Registration
Introduction
Mr W C HO, EDB
9:20 – 10:30 /
Why teachers need to implement inquiry-based
2:20 – 3:30
teaching?
Approaches and samples of inquiry-based
experiments
Prof Derek Cheung, Faculty of Ed, CUHK
10:30 – 10:40 / Break
3:30 – 3:40
10:40 – 11:45 /
3:40 – 4:45
11:45 – 12:00 /
4:45 – 5:00
How to assess inquiry-based practical work?
Samples of scoring rubrics
Prof Derek Cheung, Faculty of Ed, CUHK
More samples of inquiry-based chemistry expts
Mr W C HO, EDB
Scientific Inquiry
Inquiry - an active engaging process that mimics
the work done by actual scientists.
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
Lead to a deeper understanding of scientific
concepts
In guided inquiry, students
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choose what data to be collected
design the procedures to address the question for
investigation
In open inquiry, students make almost all the
decisions including the questions for investigation
Scientific Inquiry
“The diverse ways in which scientists study the
natural world and propose explanations based
on the evidence from their work.”
“The activities through which students develop
knowledge and understanding of scientific ideas,
as well as an understanding of how scientists
study natural world.”
US National Science Education Standards
http://www.nap.edu/readingroom/books/nses/html/pdf/index.html
Scientific Enquiry
http://www.standards.dfes.gov.uk/keystage3/res
pub/sc_enquiry
National Curriculum Handbook for Teacher
DfES, UK
“Inquiry-based teaching engages students in
investigations to satisfy curiosities, with
curiosities being satisfied when individuals have
constructed mental frameworks that adequately
explain their experiences.”
“Inquiry-based teaching begins or at least
involves stimulating curiosity or provoking
wonder. There is no authentic investigation or
meaningful learning if there is no inquiring mind
seeking an answer, solution, explanation, or
decision.”
Types of Scientific Enquiry
Surveys and correlations (pattern seeking)
Controlling variables (fair test)
Identification and classification
Using and evaluating a technique
Technology (make something or invent a system
to solve the problem)
Using experimental models and analogies to
explore an explanation, hypothesis or theory
Using secondary sources
→appropriate approach to solve the problem
Goldsworthy A, Watson R, &
Robinson V W (2000) Developing
Understanding in Scientific Enquiry,
ASE
Sang D & Robinson V W (2002)
Teaching Secondary Scientific
Enquiry, ASE
Authentic Investigations that are
Meaningful to Students
Drain Cleaners
Mosquitoes repellants
Antioxidants in fruits and tea
Vitamin C in fruits and drinks
(Does Ribena contain 4 times the vitamin C of oranges?)
Biodiesel from vegetable oils
Fuel cell from pencil and aluminium can
Hot cup and fever eliminator
Preventing corrosion of metals
Colour-safe bleach
Skin whitening cream
Tooth whitening strip
Chloride content in foodstuffs
Prevent metal from corrosion (e.g. bridge, wok)
Quantitative Investigations
Do iron tablets deteriorate?
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Titration of iron(II) sulphate with KMnO4
The salt content of different foods
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Titration of chloride ions with AgNO3 using
KCrO4 as indicator
Chlorine in swimming pools
Qualitative Investigations
Oxygen-absorber
(脫氧劑/脫酸素劑)
present in packages
of moon-cakes
Find out the chemical
species responsible
for oxygen absorption
Simple chemical tests
Preparative Investigations
Biodiesel
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Energy crisis
Demonstrate the green chemistry principle
of using renewable resources
Prepare biodiesel from vegetable oils
Compare properties with other fuels
http://www.chemsoc.org/networks/learnnet/
green/biodiesel/home.htm
Amazing Miracle
Use milk in making
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Plastic
Glue
Invisible glove
Photographic film
Fire resistant paint
Natural Mosquito Repellant from Fruit Peels
Mosquito-borne diseases
e.g. Dengue fever,
A
Japanese encephalitis
N,N-diethyl-3methylbenzamide (DEET)
container
避蚊胺
with
essential
Terpineol in fruit peels
oil
Fradin, M.S. & Day, J. F. (2002)
Comparative Efficacy of Insect
Repellents against Mosquito
Bites. New England J. of
Medicine. 347(1), pp.13-18
http://content.nejm.org/cgi/cont
ent/full/347/1/13
B
T-shaped
tube
container
with
distilled
water
bottle containing
mosquitoes
Design and Make Investigations
Using enthalpy changes for
heating and cooling in camping
Design and make a self-heating
can to heat the coffee contained
in a standard size can to 65oC
and to maintain it at this
temperature for up to 30 minutes
Design and make
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a pocket hand-warmer
a system that could be used to keep
drink cool
Aluminium-Air Fuel Cell
Construct useful things
from waste materials
Design and construct an
aluminium-air fuel cell from
soft drink cans
Investigate the current
produced with different
electrolytes
Investigate the cell e.m.f.
and current produced with
different metal anodes
http://www.ectechnic.co.uk/
fuelcell.html
Fair Tests
Investigating the effects of
varying fuels and electrolytes on
the electrical energy generated
in an alkaline fuel cell
http://chem.hku.hk/~fuelcell/dem
o.htm
Further investigations on
electrochemical cells:
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determine the concentration of
unknown solution
potentiometric titration
Menthos and Cola
Adds a "Menthos" type candy to a glass of soda
pop. Students observe an increase in "fizz" or
release in carbon dioxide.
Possible explanations?
Investigations: different candies / cola, no. of
candies, temp, container, shape of candy
http://www.consumptionjunction.com/downloads
new/cj_49646.wmv
http://www.scienceman.com/scienceinaction/pgs
/demo_9u2_01.html
CD-ROM
Possible Chemistry Investigations
Laboratory Investigations
http://chem.lapeer.org/Chem2Docs/Index.html
Problem-solving Activities
http://www.chemsoc.org/networks/learnnet/rscpubs.htm
In Search of Solutions
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Egg Races (enjoyable, competitive, practical problemsolving activities which required some application of
chemical principles); free download
In Search of More Solutions
Investigation Sheets
http://www.york.ac.uk/org/seg/salters/chemistry/ResourceSheets/rs
index.html
Background, Practical Techniques, Where to Start, Possible
Investigations, Source of Information, Teacher Notes
Teachers’ role
Choose activities that match students’ background
knowledge and reasoning skills
Communicate effectively to students what the
educational purposes of the investigation (learning
of scientific process and answering the question
being investigated)
Challenging students to defend the quality of their
evidence and arguments
Creating an environment in which students become
critical of their own and others’ evidence
Expose students’ thinking and make it more
accessible to discussion and development using
displayed questions or variable tables, etc
Questioning
Strategies for helping students ask
questions
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Provide students with an observable
phenomenon to ask questions about
Have students read articles regarding
interesting happenings in science
Suggest possible topics for investigation (a list
of possible investigations) e.g. How much
NaOCl is found in commercial bleaches and
how does it compare to the claimed?
Edwards, C H(1997)
From Cookbook to Inquiry
Transition to inquiry-based instruction by
implementing changes gradually e.g. remove the
data table
Shifting toward guided and open inquiry by
continuing to remove the supports of the activity
Assessment should stress goals in scientific
reasoning and critical thinking in addition to
content knowledge
Assess students’ abilities to generate openended and researchable queries, devise
scientific procedure, interpret data
Assessment
Achievement level matrixes in internal assessment of
International Baccalaureate (IB)
2 aspects apply to data collection (collecting and
recording raw data; organizing and presenting raw data),
data processing and presentation, and manipulative
skills
3 aspects apply to planning, conclusion and evaluation,
personal skills
Level
Completely
Partially
Not at all
3
2
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1
1
0
0
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References
Baumgartner E. (2004). Student Poster Sessions. The
Science Teacher. March, pp. 39-41.
Colburn, A. (2004). Inquiry scientists wants to know.
Educational Leadership. 62, pp.63-66.
Colburn, A. (1997). How to make lab activities more open
ended. CSTA Journal, pp.4-6.
Edwards, C. H. (1997). Promoting Student Inquiry. The
Science Teacher. 64 (7). pp.18-21.
Lechtanski, V.L. (2000). Inquiry-based Experiments in
Chemistry. New York: Oxford University Press.
Lunsford, E. & Melear, C. T. (2004). Using scoring rubrics to
evaluate inquiry. J. of College Science Teaching, Sept.
侯傑泰 (2004)《 專題研究手冊初級版》香港:朗文。
侯傑泰 (2004)《 專題研究手冊進階版》香港:朗文。
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