Aomori Entrance Science common mistakes
Aomori Entrance Science · Understand the traps and how to avoid them.
When calculating average speed or acceleration from a distance–time or speed–time graph, the candidate reads off a single point's value and divides or subtracts without checking that the interval used matches the question (e.g., dividing total distance by a partial time, or using the gradient of a curved section as if it were constant).
Graph work is taught as 'read the number off the graph', so candidates treat any two numbers as a valid calculation and never ask whether the quantity is defined over that interval. The distinction between instantaneous and average quantities is abstract and easily collapsed under time pressure.
What to do instead
Before any calculation, write the defining formula in words (average speed = total distance ÷ total time; acceleration = change in velocity ÷ time taken) and explicitly mark the two endpoints on the graph that the formula requires. For curved graphs, state that only the tangent at a point gives instantaneous speed and that a chord gives an average. Practise three-item drills where one distractor is a plausible wrong-interval answer, and justify rejection of each distractor in one sentence.
The candidate equates 'force is acting' with 'motion is happening', so they claim a ball at the top of its flight has zero force on it, or that a constant push is needed to keep a trolley moving at steady speed on a frictionless surface, and they draw the force arrow in the direction of motion rather than in the direction of the interaction.
Everyday pushing and carrying builds an Aristotelian intuition that motion requires force. Newton's first law is stated in words that are easy to recite but rarely applied to a specific free-body diagram, so the misconception survives memorisation.
What to do instead
For every mechanics problem, draw a free-body diagram first and list only interactions (gravity, normal, tension, friction, applied). Then apply the rule 'net force zero ⇒ velocity constant (including zero)' as a written check. Include a frictionless-surface case and a peak-of-flight case in every practice set so the intuition is repeatedly contradicted, and require the candidate to name which interaction produces each arrow.
On energy questions the candidate treats 'energy is conserved' as 'energy is not transferred', writing that kinetic energy disappears at the bottom of a slide or that a battery 'uses up' current, and they omit the dissipated heat when accounting for a falling or sliding object.
Conservation is memorised as a slogan about totals, not as a bookkeeping rule about transformations. Candidates also conflate current with energy because both are described as 'used up' in everyday speech.
What to do instead
Require an energy bar chart or Sankey-style account for every energy item: initial store, transfers, final stores, and the dissipated pathway explicitly labelled. For circuits, insist on the distinction 'current is the rate of charge flow and is not consumed; energy is transferred per coulomb (voltage)'. Mark any answer that says energy 'disappears' as wrong and make the candidate rewrite it naming the store it moved to.
When identifying a substance or a change, the candidate relies on a single observation (colour, fizzing, or a melting point) and labels the change as chemical or physical without checking whether a new substance formed, and they confuse a mixture with a compound when naming what is present.
Observation and inference are taught together, so a vivid observation feels like a conclusion. The physical/chemical distinction has borderline cases (dissolving, burning of a candle) that reward careful criteria, but candidates default to 'it looked dramatic, so it was chemical'.
What to do instead
Train a two-column habit: observation (what was seen or measured) versus inference (what it implies), and apply the criterion 'is a new substance formed, with different properties and composition?' before labelling. For mixtures versus compounds, require evidence about fixed proportions and separation by physical means. Use deliberate borderline cases (dissolving salt, burning magnesium, melting ice, rusting) and require a written justification for each classification.
The candidate balances a chemical equation by adjusting subscripts inside formulas rather than coefficients, or 'balances' it by inspection without a final atom count, and then carries the wrong formula into a mole or mass calculation.
Subscripts and coefficients look like the same kind of number on the page. Inspection balancing works for simple equations, so the candidate never builds the habit of a systematic atom audit, and the error is invisible once the equation 'looks right'.
What to do instead
Enforce a fixed procedure: write the word equation, write correct formulas from valency, then balance only by placing coefficients, then count each element on both sides in a table and record the totals. Treat any change to a subscript as a prohibited move. Follow every balanced equation with a check that the formula is still chemically correct, and include at least one equation requiring a fractional intermediate coefficient to be cleared.
On cell and reproduction questions the candidate mixes the scales and products of mitosis and meiosis, stating that meiosis produces identical diploid cells or that mitosis halves the chromosome number, and they describe fertilisation as restoring the body cell chromosome number without specifying that the gametes were haploid.
Both processes are drawn as similar-looking division sequences, and the vocabulary (diploid, haploid, homologous) is learned as labels rather than as quantities. Candidates memorise the diagram shapes but not the chromosome count at each stage.
What to do instead
Require a chromosome-count table for each stage of both processes, starting from a stated 2n number, with the purpose of each division written beside it (growth and repair versus gamete formation and variation). Insist on the wording 'haploid gametes fuse to form a diploid zygote'. Practise questions that give a species with a specific chromosome number and ask for counts at named stages, so the answer must be a number, not a label.
The candidate explains natural selection as an individual organism 'trying to adapt' or 'deciding to change' during its lifetime, and describes evolution as progress toward a goal, rather than as a change in the frequency of inherited variants in a population across generations.
Everyday language uses 'adapt' for individual adjustment (getting used to cold, building tolerance), and textbook diagrams compress many generations into one arrow, hiding the population-level mechanism. The word 'adaptation' is used for both the process and the trait.
What to do instead
Force the full four-step chain in every answer: variation already exists in the population; some variants leave more surviving offspring in that environment; the inherited variants become more common; over generations the population's characteristics shift. Ban 'tried to', 'decided to', and 'needed to' as explanations and require the candidate to rewrite any such sentence. Use a one-generation-versus-many-generations contrast question so the timescale is explicit.
When reading a geological or weather context, the candidate treats the map or cross-section as a picture to describe rather than as ordered evidence: they claim the top layer is always the oldest regardless of folding or faulting, or they read isobars as if closer spacing meant weaker wind, or they confuse weather with climate from a single day's data.
Relative dating rules (superposition, cross-cutting, folding) are taught as separate facts and not as a decision procedure to apply to an unfamiliar diagram. Isobar spacing and the pressure–wind relationship are easily inverted because both 'more lines' and 'more wind' feel like 'more'.
What to do instead
Give an explicit ordering routine for rock sequences: identify any folding or faulting first, then apply superposition and cross-cutting relationships, then write the sequence as a numbered list with a reason per step. For weather, memorise one sentence: 'closely spaced isobars = steep pressure gradient = stronger wind', and practise converting a station reading into a description. For climate versus weather, require the timescale to be stated before any conclusion.
The candidate reports a measurement without regard to the instrument's resolution or repeats, writing a value such as 23.47 cm from a ruler marked in millimetres, and they record a mean of repeated readings without stating the spread or noticing that one reading is an outlier caused by a misread scale.
Digital displays and calculators suggest that more digits mean more precision. Significant figures and uncertainty are often taught as a separate arithmetic topic, disconnected from the act of reading a scale, so the candidate never links the instrument to the reported digits.
What to do instead
Establish the rule at the point of measurement: record to the smallest division plus one estimated digit, and state the resolution next to the value. For repeats, require the table to show every reading, the mean, and the range, and require an outlier to be identified with a probable cause before it is excluded. Include a marking drill where the candidate must judge whether a reported value is consistent with the stated instrument.
When a question presents a table or graph of experimental data, the candidate describes the trend in vague terms ('it increased', 'they are related') without identifying the variables, the pattern of proportionality, or the anomalous point, and then draws a conclusion about cause that the data cannot support.
Data interpretation is often assessed as a writing task, and candidates believe a longer answer is a better one. They also confuse correlation with causation because the experiment's purpose is stated in the question, so the conclusion feels already given.
What to do instead
Impose a fixed answer frame: name the independent and dependent variables with units; state the pattern including what happens to the dependent variable when the independent variable doubles; identify any point that departs from the pattern and give a plausible reason; state the conclusion limited to the range tested; state one improvement to the method. Require the conclusion sentence to begin 'Within the range tested...' so overreach is visible.