22. Assessed scientific skills
- Syllabus
- 0610–2026–2027
- Section
- 22
- Level
- —
Exam analysis
22.1 Handling information and problem-solving
- Syllabus
- 0610–2026–2027
- Topic
- 22.1
- Level
- —
Select and present relevant information
Scientific information handling begins by locating the evidence that answers the question, selecting only relevant details, organising them logically and presenting them in a form another reader can follow.
| Action | What to do | Check |
|---|---|---|
| locate | identify the named source, variable, group, time or condition | every detail comes from an available source |
| select | match command words and choose only evidence that addresses them | no irrelevant biology replaces the requested evidence |
| organise | group comparisons, sequence processes or order values consistently | like is compared with like |
| present | use concise prose, a labelled table, graph or calculation as required | labels, units and precision are retained |
Selection is not copying everything. Do not omit inconvenient data, invent missing values or change units while reorganising evidence.
Translate information without changing its meaning
Translation changes the form of information—verbal, symbolic, graphical or numerical—while preserving the same variables, values, units and relationship.
| From → to | Translation method |
|---|---|
| words → graph | identify variables, put the independent variable on x and measured outcome on y, choose an even scale, plot and label |
| graph → words | state the overall direction, important phases or turning points and supporting values with units |
| graph → number/table | read from the correct curve and both axes, using the scale between labelled marks |
| numbers → symbols | write the correct relationship, substitute values with units and preserve direction or sign |
A smooth curve or connecting line must reflect the data or stated relationship. Do not add a causal explanation when the task only asks for translation.
Manipulate data accurately
Data manipulation transforms given values by a justified mathematical operation while preserving units, precision and meaning.
| Step | Accuracy check |
|---|---|
| 1 identify the required quantity | write what must be found and its unit |
| 2 select source values | read the correct row, column, curve or condition |
| 3 choose the operation | difference, total, mean, rate, ratio or percentage change must match the wording |
| 4 calculate | show substitution and keep extra digits until the end |
| 5 report | give the requested unit, decimal places or significant figures |
| 6 sense-check | verify sign, size and direction against the original data |
A rate is change divided by time. For example, use the difference between final and initial readings, then divide by the elapsed time; do not divide an unrelated total by time.
Accuracy includes choosing the right data and operation, not merely pressing the calculator correctly.
Describe patterns, trends and conclusions
A pattern or trend describes what the evidence does; a conclusion answers the investigation question using that evidence.
| Evidence task | Strong response |
|---|---|
| identify a pattern | state the overall direction or association |
| report a trend | divide the range into meaningful phases and note peaks, plateaus, fluctuations or anomalies |
| compare groups | use comparative language at the same condition and support it with paired values and units |
| form a conclusion | state what the results support, limited to the tested range and variables |
Support descriptions with accurate values, intervals or calculated changes. A data quote earns its place by demonstrating the stated pattern, not by sitting separately from it.
Describe first; do not explain causes unless asked. Correlation shows variables change together but does not by itself prove causation.
Explain phenomena and relationships with evidence
A reasoned explanation links the observed evidence to relevant biological knowledge through a clear causal chain.
| Part | Question to answer |
|---|---|
| observation | what pattern, difference or phenomenon is shown? |
| mechanism | which biological process can produce it? |
| link | how does that process change the measured outcome? |
| evidence | which value or comparison supports the link? |
| limit | is another explanation possible, or does the evidence show correlation only? |
Use directional causal language: because, therefore, increases, decreases, leads to. When discussing, include supported advantages and disadvantages before making a qualified judgement.
Repeating the trend is not an explanation. A plausible biological fact must be connected explicitly to the evidence and outcome.
Make evidence-based predictions
A prediction extends an observed relationship or pattern to a specified new condition and states the expected outcome.
| Step | Decision |
|---|---|
| 1 locate the relationship | identify its direction, shape and range |
| 2 locate the new condition | decide whether it lies within the measured range or beyond it |
| 3 interpolate or extrapolate | estimate from nearby values or extend the supported trend cautiously |
| 4 report | give the predicted value or outcome with units and suitable precision |
| 5 qualify | state uncertainty when the pattern is irregular, near a limit or extended beyond observed data |
A prediction follows evidence; it is not a guess or an explanation. Do not assume a linear trend continues indefinitely when the data curve, plateau or biological limit suggests otherwise.
Solve unfamiliar scientific problems systematically
An unfamiliar problem becomes manageable when its information is mapped to a known syllabus principle, then solved with a transparent qualitative or quantitative chain.
| Step | Action |
|---|---|
| decode | identify the command word, target quantity or decision and all constraints |
| map | connect the unfamiliar context to a relevant biological principle or mathematical relationship |
| plan | select the necessary evidence and order the reasoning or calculation |
| execute | compare options or calculate with units, showing working |
| judge | state the decision directly and justify the choice from evidence |
| verify | check units, significant figures, feasibility and whether every constraint was used |
For percentage change use (new − original) ÷ original × 100. For fair comparisons, standardise by the relevant mass, area or time when the question requires it.
Do not choose an option from one favourable value while ignoring another stated constraint. In hypothesis tests, calculate comparable quantities before deciding whether the evidence supports the claim.
22.2 Experimental skills and investigations
- Syllabus
- 0610–2026–2027
- Topic
- 22.2
- Level
- —
Select and use apparatus safely and accurately
Choose a technique, apparatus and material because it fits the quantity, range and precision required; then use it in the correct sequence while controlling its hazards.
| Need | Selection and use |
|---|---|
| volume | use a suitably sized measuring cylinder, pipette or syringe; read the meniscus at eye level on a flat surface |
| mass | use a balance with suitable resolution, zero it and measure only the intended sample |
| temperature | use a thermometer and maintain conditions with a water-bath or incubator |
| time | use a stop-clock and define consistent start and end points |
| length | use a ruler with the scale close to the object and avoid parallax |
Identify the specific hazard, state the possible harm and match it to a precaution: for example, eye protection for irritant splashes, forceps or a tile for cutting, and a water-bath rather than a naked flame near flammable material.
Naming apparatus or saying ‘be careful’ is insufficient. Justify suitability and explain how the precaution reduces the named risk.
Plan a valid and safe investigation
A valid plan changes one independent variable, measures a dependent variable and controls other factors so any observed effect can be attributed to the intended change.
| Planning decision | Required detail |
|---|---|
| question and prediction | state the relationship being tested and a reasoned expected direction |
| independent variable | choose a suitable range with enough values and equal or justified intervals |
| dependent variable | state exactly what is measured, how and in which units |
| controlled variables | name each important factor, how it is kept constant and why it could affect the result |
| method and apparatus | give a reproducible sequence, quantities, timings and justified equipment |
| control | include a comparison lacking the tested factor when appropriate |
| reliability | repeat at each value, identify anomalies and calculate a mean |
| safety | link each material or procedural hazard to a suitable precaution |
| results | specify a headed table and how data will be processed or graphed |
‘Make it a fair test’ is not a plan. State operational details, and do not confuse a controlled variable with a control treatment.
Record observations and measurements correctly
A scientific record preserves what was observed or measured with enough precision, units and structure for another person to analyse it.
| Evidence | Recording rule |
|---|---|
| analogue reading | read at eye level, use the correct meniscus and estimate one digit where the scale permits |
| digital reading | record all displayed digits unless instructed otherwise |
| repeated measurements | keep raw replicates in separate columns and calculate the mean separately |
| qualitative observation | state the actual colour, appearance or change, not merely ‘positive’ |
| results table | put the independent variable first; include units once in headings, not in every cell |
| estimate or calculation | show working and report the requested significant figures |
Values measured by the same apparatus should normally use consistent decimal places. Record sufficient observations across the chosen range and never silently replace an anomalous raw result.
Precision is the resolution and consistency of recording; it does not guarantee accuracy. Units belong in headings and must match the measured quantity.
Interpret and evaluate experimental data
Interpretation extracts a relationship from observations; evaluation judges how strongly the data support it and where data quality limits the conclusion.
| Step | Evidence-based action |
|---|---|
| process | calculate means, rates or changes consistently and present a suitable graph |
| interpret | state direction, shape, range, peak or plateau and support it with values and units |
| inspect | identify anomalous points by their departure from repeats or the overall pattern |
| act | check the raw record and repeat the measurement where possible; exclude only with justification |
| conclude | answer the tested relationship within the investigated range |
| evaluate | consider spread, repeats, sample size, resolution, uncontrolled variables and whether association proves causation |
Use interpolation within the measured range and extrapolation beyond it with caution. A gradient or intercept is meaningful only when taken from an appropriate best-fit line or curve and reported with units.
Do not call every inconvenient result anomalous, and do not remove an anomaly simply to improve the trend. A conclusion must acknowledge contradictory evidence and limitations.
Improve a method by targeting its weaknesses
A useful method evaluation identifies a specific weakness, explains its effect on the evidence and proposes a feasible change that directly reduces that weakness.
| Weakness | Likely effect | Targeted improvement |
|---|---|---|
| too few repeats or small sample | low reliability; chance variation has more influence | increase repeats or sample size and calculate a mean |
| subjective endpoint | inconsistent judgement | use a colorimeter, data logger or defined endpoint where suitable |
| uncontrolled condition | confounding change in the dependent variable | monitor and keep the named factor constant |
| coarse apparatus scale | large reading uncertainty | use apparatus with finer resolution and suitable range |
| narrow or sparse independent-variable range | trend or optimum is poorly resolved | add values across the range, especially near the changing region |
| biased sampling | sample does not represent the population | use random sampling and an adequate sample size |
Write evaluations as weakness → effect → improvement. If a control is missing, add the correct control and explain which alternative cause it rules out.
‘Use better equipment’, ‘repeat’ or ‘be more accurate’ is too vague. Name what changes, how it is used and which error, validity or reliability problem it addresses.
22.3 Mathematical and data-presentation skills
- Syllabus
- 0610–2026–2027
- Topic
- 22.3
- Level
- —
Calculate biological quantities accurately
Translate the required biological quantity into a mathematical relationship, substitute compatible values, calculate, then report with the requested unit and precision.
| Task | Relationship or check |
|---|---|
| percentage | part ÷ total × 100 |
| percentage change | (new − original) ÷ original × 100; retain a negative sign for a decrease when change is requested |
| rate or gradient | change in dependent variable ÷ change in independent variable; include compound units |
| mean and range | sum ÷ number; maximum − minimum |
| ratio/proportion | compare like units; scale every term consistently |
| formula | rearrange for the unknown, substitute values with units, then solve |
| standard form | write a × 10ⁿ where 1 ≤ a < 10 |
Keep unrounded calculator values during working and round only the final result to the stated decimal places or significant figures. Show selected values and substitution so the method is traceable.
Percentage change uses the original value as denominator. A percentage increase may exceed 100%, and ordinary percentage is not interchangeable with percentage change.
Convert units and work with biological scale
Convert all quantities to compatible units before applying area, volume, scale or surface-area-to-volume relationships.
| Conversion | Direction rule |
|---|---|
| 1 kg = 1000 g; 1 g = 1000 mg | larger mass unit → smaller: multiply by 1000 |
| 1 m = 100 cm = 1000 mm; 1 mm = 1000 μm | follow each length conversion explicitly |
| 1 dm³ = 1000 cm³ | dm³ → cm³: multiply by 1000 |
| area | square the length conversion factor |
| volume | cube the length conversion factor |
| Shape or scale | Relationship |
|---|---|
| rectangle | area = length × width |
| triangle | area = ½ × base × height |
| circle | area = πr²; circumference = 2πr |
| rectangular block | volume = length × width × height |
| cylinder | volume = πr²h |
| scale diagram | actual size = image size ÷ magnification |
| surface-area-to-volume ratio | calculate both in compatible units, then simplify SA:V |
Linear conversion factors cannot be used unchanged for area or volume. State an appropriate final unit such as cm², μm³ or stomata per cm².
Choose and interpret graphs, charts and statistics
Choose a representation that matches the data type, then read its scale, trend and numerical features without changing the underlying evidence.
| Data or purpose | Suitable representation |
|---|---|
| continuous change or relationship | line graph or scatter graph with justified best-fit line/curve |
| categorical or discrete groups | bar chart with equal-width separated bars |
| continuous frequency intervals | equal-interval histogram with touching bars |
| proportions of a whole | pie chart |
Read values to half a smallest square where possible. Interpolation estimates within the data range; extrapolation extends beyond it and is less certain. Gradient is Δy/Δx with units, and an intercept is where a line crosses an axis.
Calculate mean and range from the defined set. Recognise direct proportion as a straight line through the origin; inverse proportion falls as the other variable rises. Simple probability ranges from 0 to 1.
Bars touch only for continuous histograms. A line joining points is not automatically a best-fit line, and a straight trend not through the origin is not direct proportionality.
Record readings and tables to official conventions
Recorded data must reflect instrument precision and preserve quantity, unit and significant-figure conventions consistently.
| Feature | Required convention |
|---|---|
| instrument reading | record the smallest reliably detected scale difference; use consistent decimal places for the same instrument |
| calculated result | use appropriate or requested significant figures and include the unit |
| table heading | write quantity / unit, for example time / s |
| table body | enter numbers only; do not repeat units in cells |
| columns | put the independent variable first and keep raw repeats separate from a calculated mean |
| missing or anomalous value | preserve the raw record; do not invent or silently replace a value |
Significant figures describe meaningful digits; decimal places describe position after the decimal point. They are different instructions.
Plot and present biological data clearly
A valid presentation makes variables, values and biological structures readable without exaggerating precision or inventing detail.
| Graph feature | Official requirement |
|---|---|
| axes | independent variable on x and dependent on y unless instructed otherwise; label quantity / unit |
| scale | use more than half the grid in both directions with sensible 1, 2 or 5-based intervals; zero is not always required |
| points | mark clear × or encircled dots within half a smallest square |
| best fit | draw one thin smooth line or curve with points reasonably balanced around it; ignore a clear anomaly only for the fit |
| reading | show interpolation or extrapolation guides and read to half a smallest square |
Biological drawings use a sharp pencil, large clear unbroken lines, no shading or colour, all observed features, and ruled label lines that touch the labelled feature.
Use a pie chart for proportions, separated equal-width bars for categorical or discrete data, and touching bars for continuous histogram intervals.
Draw a best-fit line only when intermediate values can reasonably be predicted. Do not force it through every point or through the origin without evidence.