Common Mistakes

[Lear]

Where did you hear this? This is beyond insane.

2017 Examiners report

Many students did not write a recurrence relation in the required form.
A recurrence relation has the initial value written first

2016 Examiners report

A recurrence relation has the initial value written first, followed by the recurrence rule

Extremely, extremely pedantic.

[vceme]

- not checking whether the correlation coefficient is positive or negative from the graph
- not checking whether the x-axis starts with 0 or not and getting stressed why ur points don't line up lmao
- accidentally putting the opposite sign for the finance equations
- switching the dependent/ independent variables
- all time series plots have irregular fluctuations !!!!!!! I believe that if it ask just for trends, its either positive or negative

[S_R_K]

2017 Examiners report
2016 Examiners report
Extremely, extremely pedantic.

Checked this with a teacher who has marked for the past couple of years. He said that he did not penalise responses which wrote the rule for Vn+1 above or to the left of the value of V0, and he does not recall being given any specific advice otherwise. We were not sure what the examiners report is getting at.

[Lear]

Checked this with a teacher who has marked for the past couple of years. He said that he did not penalise responses which wrote the rule for Vn+1 above or to the left of the value of V0, and he does not recall being given any specific advice otherwise. We were not sure what the examiners report is getting at.

That’s excellent to hear. It would be extremely silly for VCAA to mark down something such as that. Especially in a subject such as further where each mark is very valuable.

Thank you for your insight!

[kat01]

if they ask for mean smoothing, check if they want it with centering or not! i always forget to do centering, even if the question asks for it lol

[Lear]

if they ask for mean smoothing, check if they want it with centering or not! i always forget to do centering, even if the question asks for it lol

Make a spreadsheet template that does the smoothing for you

[studyingg]

more of a general one: but mixing up whether they want you to select a true or false statement in multiple choice

Data analysis:

- not using key terms like 'no clear pattern' (why a residual plot supports the assumption of linearity), or the word 'differ' ( when suggesting that a set of bivariate data depicts an association)

-not mentioning the number of outliers when describing the shape of a spread (if it's clear)

-if you are interpreting smoothed data, only interpret using the values that have actually been smoothed, and not lost as a result of smoothing.
e.g for 3 median smoothing of a time series plot from January to december that depicts an increasing trend: make sure to say the smoothed time series plot indicates an increasing trend in [whatever the response variable is] from february to november. (bc u lost jan and dec)


Financial:
-making sure to keep track of the entire period of reducing balance loan (or other type of loan/investment) with changing conditions. For example if they changed the payment at some point,or there is a lump sum included and then it asks you to find the total payment make sure to include everything!!

-pay attention to whether the interest rate is monthly/quaterly/per annum etc. (especially in multiple choice!)

-don't assume that the payment made in an ammortisation situation is constant


So I think a key theme with FM mistkakes is making baseless assumptions, and not reading the bloody question!

[vceme]

more of a general one: but mixing up whether they want you to select a true or false statement in multiple choice



-if you are interpreting smoothed data, only interpret using the values that have actually been smoothed, and not lost as a result of smoothing.
e.g for 3 median smoothing of a time series plot from January to december that depicts an increasing trend: make sure to say the smoothed time series plot indicates an increasing trend in [whatever the response variable is] from february to november. (bc u lost jan and dec)

do you mind giving a question for this example? i've never encountered this before 

[studyingg]

do you mind giving a question for this example? i've never encountered this before 

Sorry for the late response VCAA 2009 exam 2 (see the last sentence in the solution for question 2c)

[Seth]

Has anyone made mistakes when they ask you which of the following is true/not true?

Sometimes I make the stupidist of mistakes!

[plato]

2017 Examiners report
2016 Examiners report
Extremely, extremely pedantic.

Examiners have explained that this is the preferred order of writing the two parts of a recurrence relation, but noone has lost a mark if they had reversed the order. As long as the two parts are there and both are correct, you should get the mark. But it might be sensible to follow their preferred order if you can remember to do it.