Cambridge HSC common mistakes
Cambridge HSC · Understand the traps and how to avoid them.
In practical write-ups, recording an inference as the observation, e.g. writing 'the metal reacted vigorously' instead of 'gas bubbles formed and the tube became warm to touch'.
School practicals often reward the conclusion, so students compress what they saw into what it meant; observation marks cannot be awarded for a conclusion.
What to do instead
Use a two-column table: left column 'what I saw or measured' (colour, bubbles, temperature to 0.1 °C), right column 'what it suggests'. Convert every 'because' sentence into a separate numbered observation.
When asked to assess validity or reliability, writing 'it was accurate because we repeated it' while ignoring an uncontrolled variable such as room temperature.
Repeatability and validity are conflated; repeats feel like rigour, so students stop at the number of trials.
What to do instead
Write one-line definitions first: validity = the method controls variables and tests the aim; reliability = repeats give consistent results. Then name one specific uncontrolled variable and state the direction it would push the result.
Jumping from the question straight to a final answer without a substituted formula or intermediate line, especially in calculus, projectiles and titration calculations.
Students have been rewarded for the right answer and feel time pressure, so they treat working as optional rather than as assessed method.
What to do instead
Make a three-line routine compulsory in practice: substitute the values into the formula, simplify one line at a time, then state the answer with units. Mark your own work twice-once for the answer, once for the method.
Treating 'hence' as 'hence or otherwise' and restarting a long method instead of using the result from part (a).
Command words are skimmed under time pressure, and a fresh method feels safer than trusting an earlier part that may be wrong.
What to do instead
Circle the command word before writing. If it says 'hence', begin the next part with the sentence 'Using part (a), ...' and quote the earlier result symbolically before substituting.
Producing a word-for-word rendering of idioms and connectives, e.g. translating 'however' with the target-language word for 'but', or using a formal connector in a friendly email.
Students look up single words in a dictionary and do not store multi-word chunks, so register and collocation are invisible to them.
What to do instead
Learn ten whole collocations per topic, not isolated words, and classify each as formal, neutral or informal. Before writing, identify the text type and audience, then check every connector against that register.
In reading and listening tasks, choosing an option from one matching keyword without reading the full clause, so negation, tense or a change of subject is missed.
Keyword scanning is taught as a speed strategy, and once a familiar word appears the student stops processing.
What to do instead
Locate the keyword, then bracket the whole sentence and underline negation, time markers and subject changes before looking at the options. Reject any option that contradicts one of those three features.
Listing points without a causal chain or data reference: 'Inflation rises. This is bad for consumers.'
Recall of syllabus points is mistaken for analysis, and students do not know that the marks sit in the linkage and the stimulus data.
What to do instead
Force a chain for each point: 'because ... therefore ... which means ...'. Then attach one figure from the stimulus with its units and say what it shows. No paragraph without both a chain and a data reference.
Retelling the content of a source chronologically instead of making an argument that answers the question, with the essay only revealing its position in the conclusion.
Source anxiety leads students to summarise to show they read it; earlier schooling rewarded narrative over thesis.
What to do instead
Write a one-sentence thesis in the introduction containing a stance and two reasons. Make each paragraph's first sentence one of those reasons, and use sources only as evidence inside the paragraph, never as a summary block.
Submitting a finished product or program with no dated evidence of constraints, alternative designs, testing or evaluation against the brief.
The artefact is treated as the whole task and the folio as paperwork, so iteration and testing happen but are never recorded.
What to do instead
Keep a dated folio checklist: brief and constraints, two alternatives judged against criteria, a test-data table with expected versus actual results, and a criterion-by-criterion evaluation. Photograph or log each stage as it happens.
Describing what is depicted in an artwork or performance ('a woman in a field') rather than analysing how technique creates meaning ('the low horizon and cool palette isolate the figure').
Students have practised description in earlier years and lack a vocabulary for elements and principles, so they default to subject matter.
What to do instead
Use a three-sentence frame for every work: name a technique or structural element, state its effect on the viewer, then give a judgment. Ban subject-matter nouns unless they are tied to a technique in the same sentence.