Chemistry Department S Igcse Assessment Guidebook (DRAFT)

Chemistry Department’s iGCSE Assessment Guidebook (DRAFT)

Basically there are these main standardised ways we assess students achievement

End of topic tests (using only questions from CIE past exam papers)
Practical write up (based on the IB
Design
Data collection and processing
Conclusion and evaluation
Essays, using a rubric based on the extended essay rubric
Mini-symposia focusing on ToK, using a rubric based on the one issued for the ToK presentation
Other less formal systems like directed questioning in class, class participation, manipulative skills during practicals, ability to work within a team in practicals, verbal communication skills in class

For the practical write ups and the essays the students should be given a chance to improve their work based on your feedback so they learn more deeply where they are going wrong and how they can improve to produce the best work possible. It is therefore very useful to see these excercises very much as formative assessment rather than summative, if they get it wrong, you should tell them and then they should be given the opportunity to fix it.

Design (D)

D1- Defining the problem / D1a / You have provided a focused research question of what you intend to do. / /2
D1b / You have given a qualitative hypothesis and justified it with quantitative scientific reasoning (using a calculation or chemical equation). / /2
D1c / You attempt to explain the scientific reasoning behind the most important variables you are going to control. / /2
D2 - Selecting variables / D2a / States the independent variable (the one you change) / /1
D2b / States the dependant variable (the one you measure) / /1
D2c / States the controlled variable(s) (the one(s) that must be kept constant) / /2
D3- Developing a method for collection of data / D3a / Selects and names appropriate apparatus and materials needed / /2
D3b / Designs a method that allows for the effective control of the variables / /2
D3c / Designs a method that allows for the collection of sufficient relevant data / /2
Total marks / /16

Data Collection and Processing (DCP)

DCP1
Collect and organize raw data / DCP1a / You have successfully recorded all raw data (qualitative and/or quantitative). / /2
DCP1b / You have presented the raw data in a complete and clear manner. / /2
DCP1c / You have always used the correct headings, units and decimal places for you measurements. All of your measurements are recorded with the correct amount of precision. / /2
DCP2
Processing raw data / DCP2a / You have always made the correct calculations with the raw data. / /2
DCP2b / You have always used the correct units and significant figures in your solutions to calculations. / /2
DCP2c / You have extracted the relevant data from the graph. Where a graph is not drawn (e.g. in titrations), you have processed and presented all of the data correctly in a single table with the correct number of significant figures. / /2
DCP3
Presenting processed data / DCP3a / You have the processed data appropriately (correct choice of graph, bar chart etc.). Where further calculations are required (e.g. titrations), you have selected and shown the correct formulas needed for the calculation. / /2
DCP3b / When a graph is needed you have chosen an appropriate scale and plotted points/displayed processed data correctly/added trend line and given an equation for trend line. Where further calculations are required (e.g. titrations) you have always clearly presented a sample calculation. / /2
DCP3c / If you needed to draw a graph you have used correct labels, units and line of best fit drawn (if graph chosen). Where further calculations are required (e.g. titrations), the correct answer is presented with correct units. / /2
Total marks / /18

Manipulative Skills (MS)

MS1- Instruction / MS1a / You have followed VERBAL instructions / /2
MS1b / You have followed WRITTEN instructions / /2
MS1c / You are aware of all instructions about HEALTH & SAFETY / /2
MS2 - Technique / MS2a / You have completed the practical is a sensible way / /2
MS2b / You have completed the practical in a safe way / /2
MS3- Teamwork / D3a / You have made sure everyone in the group has done a fair amount of work / /2
D3b / You have worked effectively and efficiently in your group / /2
Total marks / /14

iGCSE Chemistry Literature Review and Essay Marking Scheme

There are two categories, relating to either Chemistry or to Scientific writing.

Each of these different skills can be awarded a Complete (2/2) a Partially complete (1/2) or a Not at all (0/2). In exceptional circumstances the teacher can award a Distinction (3/2) for a particular category, which means it is possible to get more than 100% on these essays!

Usually only one category (either 1, chemistry or 2, scientific writing) will be assessed for a given piece of work at any one time (a merit to the first student to spot this), but your use of English will almost always be assessed for every essay.

1.Demonstrating an Understanding of Chemistry (UC)

a)Knowledge

Describes, states or lists relevant information relating to the topic covered by the title.

b)Understanding

Relates the information they have given to a larger idea and uses their understanding of chemistry to EXPLAIN most or all of the information they have provided.

c)Analysis/Conclusion

Uses the information that they have provided to identify or explain any trends or larger ideas that this information supports.

d)Syllabus/subject relevance

Does not include irrelevant material and in addition, clearly demonstrates an awareness of the topics relationship to chemistry, e.g. by including correct and relevant chemical equations or by drawing appropriate and labeled diagrams.

e)Correct word count

Stays within 20% of the word limit, or if you go over, only includes ideas which are essential to the argument and does not go over by too much. Most of the highest scoring essays will be within the word limit.

2.Demonstrating an understanding of good Scientific Writing (SciW)

a)Research

Uses three or more sources of information and provides a complete bibliography.

b)Depth

The essay is to an appropriate depth considering the word limit; it EXPLAINS one particular idea very well, rather than listing just lots of related but different ideas.

c)Insight and originality

Choses an unusual or interesting topic to base the essay around, or uses an unusual and interesting approach to their essay.

d)Flair

Demonstrates a thorough understanding of the subject that goes well beyond the syllabus and whilst exploring larger ideas, is obviously aware of the syllabus.

e)Tone

Uses the correct tone for a scientific essay. Assumes the reader understands the basics of chemistry, e.g. elements and electrons (has iGCSE knowledge), but explains any vocabulary beyond that.

f)Correct word count

Demonstrating an understanding of good English

You will, in addition to either of the assessment categories above also be assessed on your English, each of these can be either, Complete (1/1) or Not at all (0/1). A merit to the first student to spot this.Your typical essay then can either be out of 13 marks for category 1 or 15 marks for category 2. Sometimes you will be required to write a longer essay that covers both categories and so will be out of 28 marks.

a)Use of correct vocabulary

Vocabulary, especially keywords, are correctly used and defined where necessary

b)Use of correct grammar

Uses grammar correctly

c)Flow of ideas

Good use of punctuation and the essay flows well, with a recognizable beginning, middle and end. Repetition of synonyms is avoided and there is a comfortable feel to the style of language used (i.e. magniloquence is avoided)

Checking Notes in Exercise Books

Not at all
0/2 / Partially complete
1/2 / Complete
2/2 / Exceptional
3/2
Neat and tidy
Clear writing
Full notes
Dates?
Titles?
All work stuck into the book
Total Score: / /12
Score / 0-4 / 5-8 / 9-12 / Above 12
Possible AtL on report / 4 / 3 / 2 / 1

Checking Notes in Exercise Books

Checking Notes in TOPIC Books

Not at all
0/2 / Partially complete
1/2 / Complete
2/2 / Exceptional
3/2
Clear and legible (can you read it?) writing
Notes and highlighting of important points
Keywords completed?
All questions answered
Some questions answered
Very few questions answered
No questions answered
Some evidence of extra reading or going beyond the syllabus?
Total Score: / /12
Score / 0-4 / 5-8 / 9-12 / Above 12
Possible AtL on report / 4 / 3 / 2 / 1

Checking Notes in Exercise Books

PresentationRubric (Adapted from ToK)

AIdentificationofknowledgeissue

•Did the presentationidentify arelevantknowledge issueinvolved,implicitorembeddedin areal-lifesituation?

DescriptorAchievement level

•Level 1 wasnotachieved.0

•Thepresentation referredtoaknowledge issuebutitwas irrelevant tothereal-lifesituation

underconsideration.1–2

•Thepresentationidentified aknowledge issue thatwasin some ways relevanttothereal-lifesituation

underconsideration.3–4

•Thepresentationidentified aknowledge issue that was clearlyrelevanttothereal-lifesituation

underconsideration.5

BTreatment ofknowledgeissues

•Did the presentation showagoodunderstandingof knowledge issues, in thecontext of thereal-lifesituation?

DescriptorAchievement level

•Level 1 wasnotachieved.0

•Thepresentationshowedsomeunderstandingofknowledgeissues.1–2

•Thepresentationshowedanadequateunderstandingofknowledgeissues3–4

•Thepresentationshowedagoodunderstandingofknowledgeissues.5

CKnower's perspective

•Did the presentation,particularlyin the useofargumentsand examples, show anindividualapproachanddemonstrate thesignificance of thetopic?

DescriptorAchievement level

•Level 1 wasnotachieved.0

•Thepresentation,initsuseofargumentsandexamples orotherwise, showed limitedpersonal

involvement anddidnotdemonstrate thesignificance of thetopic.1–2

•Thepresentation,initsuseofargumentsandexamples orotherwise, showedsome personal

involvement andadequatelydemonstrated thesignificance of thetopic.3–4

•Thepresentation,initsdistinctivelypersonaluseofarguments andexamplesorotherwise, showed

clearpersonalinvolvementand fully demonstrated thesignificance of thetopic.5

D Connections

•Did the presentationgive a balancedaccountofhow thetopiccould beapproached from different perspectives?

•Did the presentation show how the positions taken on theknowledge issueswouldhaveimplicationsin relatedareas?

•Inawarding the higher achievementlevels, theemphasis should be moreon the quality of theconsideration ofconnectionsthan on the quantity of connectionsmentioned.

DescriptorAchievement level

•Level 1 wasnotachieved.0

•Thepresentationexploredatleast two different perspectives tosome extent.1–2

•Thepresentationgave asatisfactory accountofhow the question could beapproached from differentperspectives, andbegan to explore theirsimilarities anddifferences. 3–4

•Thepresentationgave aclear accountofhow the question could beapproached from different

perspectivesand consideredtheir implicationsin related areas.5

iG Rubric Creating Exam Questions

Standard format of task:

5 multiple choice marks only assessing the “Core” syllabus material (Paper 1)

10 marks attached to longer answer questions also assessing the “Supplement” material and including at least one three or four mark question (Paper 3)

5 marks given for questions relating to experimental techniques (Paper 6)

Essential Questions

Question style -2 marks

2All of the questions are of the same style as you would find in a real exam

1Some of the questions are in the wrong style e.g. like true/false questions

0All of the questions are in the wrong style

Level of challenge -2 marks

2All of the questions are set to an appropriate level of challenge

1There is an inappropriate level of challenge to be used by iGCSE

0The level of challenge is totally inappropriate

Use of Command words – 2 marks

2Command words used consistently and appropriately for all questions

1Some inappropriate use of command words

0Command words totally missing or consistently used inappropriately

Clarity of task – 2 marks

2The questions use precise language and it is obvious what you are supposed to do

1There is some degree of ambiguity in in the language used so that it is not always obvious what is being asked.

0It I s really unclear what is needed to do to answer the question successfully

Breadth of syllabus coverage – 2 Marks

2There is an excellent coverage of the syllabus

1Some important aspects of the syllabus have been missed out

Essential Mark Scheme

Mark scheme style

Appropriate number of marks

Marks linked to the appropriate grade

Paper specific criteria

Paper 1

Right number of answers

Appropriate style of answers

Paper 3

Calculations are correct

Chemical equations are appropriate

Paper 6

Graph question allows an appropriate curve

Tables appropriate display appropriate trend

Essay question

Exemplar practical write up: Design (D)

Task: Design an experiment in 300 words to investigate salt solutions and temperature.

Design (D)

1a)Research Question: Investigating the effect salt (NaCl) concentration in mol dm-3 has on the boiling and freezing point measured in oC of a solution

1b)Hypothesis: Adding salt will reduce the freezing point but increase the boiling point

NaCl (s) + H2O (l)NaCl(aq)

Solutions are mixtures of a solvent, water, and a solute, NaCl. Impure substances like solutions have different fixed points to pure substances because the solute makes bonds with the solvent molecules which makes it more difficult to free them (boil). Also the solute interferes with the freezing process, so the liquid stays liquid at lower temperatures.

2a)Independent variable: Salt (NaCl) concentration (0.0, 0.2, 0.4, 0.6, 0.6 & 1.0 mol dm-3)

2b)Dependent Variable: Temperature of the melting and boiling points, oC

1c &2 c)Controlled variables: Volume of solution, type of water (used distilled), type of heater (use an electric heater), type of container (250cm3 glass beaker), kind of thermometer

3a, 3b & 3c)Method

Add a thermometer that goes up to 200oC to 100 cm3 of a salt concentration heat with an electric heater set to 200oC.
Heat each solution and measure the temperature when it boils.
To another 100cm3 of salt solution with the same concentration, cool the solution with ice and measure the temperature with the thermometer when it freezes.
Repeat 2 times for the same salt concentration.
Repeat steps 1 to 4 for each different salt concentration.

Word count: 231

Score: 16/16

This is a method for a very simple design experiment, you are essentially just heating and cooling a liquid, so there are not that many variables that need to be controlled. A more complicated experiment, like finding out the amount of energy contained in different fuels, would have much more variables, which would mean the method would need to be much longer in order to effectively control all of those variables, so it would be much harder to get full marks for that design.

iG Exemplar DCP MgO

Task: Write a 300 word lab report for the Data Collection and Processing skill for the investigation of mass change during the burning of magnesium

Data Collection and Processing Exemplar

When the DCP skill is being assessed you get no marks for providing a method, which is assessed by the Design (D) skill, nor are there any marks for a Conclusion and Evaluation, which is assessed by the CE skill.

1 – Collect and organise raw data / Record all raw data (qualitative and/or quantitative) / /2
Presents raw data clearly / /2
Uses correct headings, units and significant figures. / /2
2 – Processing raw data / Makes the correct calculations on the raw data / /2
Pays attention to units, significant figures and decimal places in final answer. / /2
Extracts relevant data from the graph if drawn (intercept, gradient etc.) / /2
3 – Presenting processed data / Presents the processed data appropriately (correct choice of graph, bar chart etc.) / /2
Chooses an appropriate scale and plots points/displays processed data correctly/adds trendline and gives equation for trendline / /2
Uses correct labels, units and line of best fit drawn (if graph chosen) / /2

Total marks available: 18

Results table (1a,1b and 1c):

Calculations (2a and 2b)

Working out the empirical formula for magnesium oxide:

According to the graph, the gradient shows that 1.56g of magnesium oxide is made for every 1g of Mg. Converting this into moles we see that in 1.00g of Mg we have 1.00/24.0 =0.0417 moles of Mg.

Of that 1.56g of magnesium oxide, 1.00 g is Mg, so 0.560g is oxygen, or 0.560/16.0=0.035 moles of oxygen.

The ratio therefore for magnesium to oxygen (the empirical formula for the compound we made) is:

0.0350/0.0350 to 0.0417/0.0350or 1.000 : 0.840

Rounding we get: 1:1 of Mg:O

Empirical formula is MgO

Graph (2c, 3a,3b and 3c)

18/18 (full marks)

Comments

Results table

All measured values to the same number of decimal places for each column (which is the number of decimal places, or accuracy, of the equipment). Each column has clear title and units and they are given using the forward slash “/”: e.g. /g, or /s or /cm3 etc.
At least 5 different data points for the independent variable present.

Graph

Drawn in pencil (and after this has been handed in kept in a safe place) – Easy corrections during this write up, as well as after feedback has been given are still possible because of this!
X axis = Independent variable (the thing that you can control).
Y axis = The dependent variable (the thing that changes as a result of how you have changed the independent variable).
The gradient, and how it was worked out, clearly shown on the graph.
Anomalous outlier (point that doesn’t fit the pattern) highlighted and ignored.

Photo of the graph(applies to all photos of hand-drawn diagrams, results tables etc)

You must take a photo that clearly shows your graph. If it can’t be read than you can’t get credit for it!

Taken from above (so the lines of the graph paper are parallel to the edges of the photo), in good lighting.
Handwriting larger than usual and clearer than usual to overcome any problems created when it is photographed.
High resolution photo, displayed in the right orientation in a word document and of a good size (both on the graph paper, but also in relation to the Word document it is displayed in.
Only potential problem is the use of MgO for magnesium oxide. It would have been better if the word name rather than the symbol name had been used because when the graph was drawn there was no way of knowing what the resulting formula for the oxide would have been. Alternatively, it could have been labelled MgxOy to indicate that the ratio was unknown.

Calculations

Done in Word, which makes processing easier (easier to mark, and much, much easier to correct).
Clearly states the purpose of what they are trying to achieve.
Use moles when necessary.
All calculated values to 3 significant figures.
Gives sample calculations for each type of calculation (in this case there was only one variety, but if e.g. many different metals had been burnt, only one sample calculation showing exactly what was done is needed, for the other metals only the ratios would have needed to be shown. A table is usually best for multiple answers.
Correct units used throughout.
Clear progression of ideas in the calculation, with explanations throughout as to what is being done.

iGCSE Exemplar essay