Science · Unit 14

Data, Graphs and Evidence

Turning results into evidence you can trust

Results are not evidence until someone organises them, and the choice of how to organise them can make the same numbers say very different things.

The unit covers building tables, choosing between bar and line graphs, spotting patterns and trends, calculating mean, median and mode, and judging when evidence is reliable enough to act on.

This unit breaks down into 22 short steps and 131 questions, starting at difficulty 3 and building to 4. Below you can see exactly what it covers, how the path is structured, and worked examples with explanations.

Steps: 22
Questions: 131
Difficulty: 3-4

What this unit covers

Mean, Median and Mode
Reliable Evidence
Tables of Data
Patterns and Trends
Bar and Line Graphs

Where this fits

Follows The Scientific Method. Math's Data and Graphs covers the same techniques from the mathematical side.

Where people slip

Bar charts and line graphs are not interchangeable. A line implies the values in between mean something, which is false for separate categories.

How the unit is structured

Data, Graphs and Evidence runs as 22 short steps that unlock in order. 16 are practice rounds and 6 are challenge rounds that pull together everything before them. Questions start at difficulty 3 and climb to 4 as you progress.

Step 1 · easierStep 22 · harder

Challenge rounds

Example questions

30 real questions from this unit, with the answer and the reason behind it, grouped by what they practise. There are 131 in the unit altogether.

Bar and Line Graphs

Choose all that applyLevel 3
1. Which should every well-drawn graph include? Pick all that apply.
- A clear titlecorrect
- Axes labelled with quantity and unitcorrect
- A sensible, evenly-spaced scale
- Randomly chosen axis spacing
A good graph has a title, axes labelled with quantity and unit, and an even scale; uneven spacing distorts the data.
Fact or fibLevel 3
2. The dependent variable (the one you measure) is usually plotted on the vertical y-axis.
Answer: True
By convention the measured dependent variable goes on the y-axis and the variable you control on the x-axis.
Fill the blankLevel 3
3. On most graphs the independent variable (the one you choose) is plotted on the ____ axis.
- horizontal (x)correct
- vertical (y)
- diagonal
- radial
The independent variable goes on the horizontal x-axis and the dependent variable on the vertical y-axis.
Match the pairsLevel 3
4. Match each chart to what it shows best.
Answer: Line graph = Change over time; Bar chart = Comparing categories; Pie chart = Parts of a whole; Scatter graph = Relationship between two variables
Each chart type suits a different job: trends over time, comparing categories, showing proportions, or showing a relationship.
Build the sentenceLevel 4
5. Build a sentence that describes what extrapolation does.
Answer: Extrapolation extends a trend beyond the measured data
Extrapolation reads values beyond the range of the data, so it is less reliable than interpolation.
Guess the numberLevel 4
6. A line of best fit passes through the origin and reaches y = 20 when x = 4. What is its gradient?
Answer: 5 per unit x
Gradient = change in y divided by change in x = 20 / 4 = 5.

Mean, Median and Mode

Fill the blankLevel 3
7. The ____ is the value that appears most often in a data set.
- modecorrect
- mean
- median
- range
The mode is the most frequently occurring value.
Guess the numberLevel 3
8. Find the median of this ordered list: 3, 7, 9, 10, 11.
Answer: 9
The median is the middle value of an ordered list; with five values the third one, 9, is in the middle.
Multiple choiceLevel 3
9. Which average is the middle value of a data set once the values are put in order?
- Mediancorrect
- Mean
- Mode
- Range
The median is the middle value of an ordered data set.
Put in orderLevel 3
10. Put the steps for finding the median of a data set in the correct order.
Answer: Write down all the values -> Put them in order from smallest to largest -> Find the middle position -> Read off the middle value
To find a median you first order the data, then locate and read off the middle value.
Choose all that applyLevel 4
11. In which situations is the median often a better choice than the mean? Pick all that apply.
- Data with a few extreme outlierscorrect
- Strongly skewed income datacorrect
- When one anomalous reading distorts the totalcorrect
- A small, evenly spread symmetric data set
The median resists outliers and skew, while the mean is fine for symmetric, outlier-free data.
Match the pairsLevel 4
12. Match each measure to its definition.
Answer: Mean = Sum divided by how many values; Median = Middle value when ordered; Mode = Most common value; Range = Highest minus lowest
Mean, median, mode, and range each summarise a data set in a different way.

Patterns and Trends

Build the sentenceLevel 3
13. Build a sentence that defines a trend in data.
Answer: A trend is a general pattern in the data
A trend is the overall pattern or direction that the data follows.
Choose all that applyLevel 3
14. Which of these are patterns you might describe in a set of data? Pick all that apply.
- An upward trendcorrect
- A downward trendcorrect
- A repeating cyclecorrect
- The colour of the ink
Trends and cycles are data patterns; the colour of the ink is not.
Fact or fibLevel 3
15. If the points on a scatter graph are spread out with no clear direction, we say there is no correlation.
Answer: True
Randomly scattered points with no upward or downward trend show no correlation between the variables.
Fill the blankLevel 3
16. A ____ correlation means that as one variable increases, the other decreases.
- negativecorrect
- positive
- zero
- direct
A downward trend, where one variable falls as the other rises, is a negative correlation.
Multiple choiceLevel 3
17. On a scatter graph, the points rise from bottom-left to top-right as both variables increase together. What is this pattern called?
- A positive correlationcorrect
- A negative correlation
- No correlation
- An anomaly
When both variables increase together the graph shows a positive correlation.
Guess the numberLevel 4
18. Five temperature readings in degrees C are 20, 21, 19, 55 and 22. Which reading is the anomaly?
Answer: 55 C
55 is far from the cluster near 20, so it is the anomaly.

Reliable Evidence

Build the sentenceLevel 3
19. Build the advice a scientist gives about checking a result.
Answer: Repeat the test to check your results
Repeating a test checks whether the result is reliable.
Choose all that applyLevel 3
20. Which of these help make experimental evidence more reliable? Pick all that apply.
- Repeating readings and averaging themcorrect
- Controlling the other variablescorrect
- Using a larger samplecorrect
- Recording only the results you expected
Repeats, controlled variables, and larger samples improve reliability; ignoring unexpected results biases the evidence.
Fact or fibLevel 3
21. A correlation between two things always proves that one of them causes the other.
Answer: False
Correlation shows a link, but a third factor or coincidence could explain it, so it does not prove causation.
Fill the blankLevel 3
22. Results are described as ____ if repeating the same experiment gives closely similar values each time.
- reliablecorrect
- biased
- random
- unfair
Reliable (repeatable) results are ones you get again when the experiment is repeated.
Match the pairsLevel 3
23. Match each term about data quality to its meaning.
Answer: Accurate = Close to the true value; Precise = Repeated readings are close together; Valid = Measures what it set out to; Bias = A systematic effect that skews results one way
Accurate, precise, valid, and bias each describe a different quality of measurements and evidence.
Multiple choiceLevel 3
24. Why do scientists usually repeat a measurement several times and then use the mean?
- To reduce the effect of random errors and improve reliabilitycorrect
- To make the experiment finish faster
- To use up spare materials
- To change the independent variable
Repeating readings and averaging them lessens the impact of random errors, giving more reliable results.

Tables of Data

Choose all that applyLevel 3
25. Which features belong in a well-designed results table? Pick all that apply.
- A clear heading for each columncorrect
- Units written in the headingscorrect
- Rows in a sensible, consistent order
- Different units mixed within one column
Good tables have labelled columns, units in the headings, and consistent ordering; units should never be mixed within a single column.
Fill the blankLevel 3
26. In a data table, a unit such as cm or s should be written once in the column ____, not beside every value.
- headingcorrect
- footer
- title
- margin
Putting the unit in the column heading keeps each cell uncluttered while every value in that column shares the unit.
Guess the numberLevel 3
27. In a tally chart, one bundle is drawn as four vertical lines with a fifth line crossing them. How many does one complete bundle stand for?
Answer: 5 marks
Tally marks are grouped in fives, so a crossed-through bundle represents 5.
Match the pairsLevel 3
28. Match each part of a data table to its job.
Answer: Column heading = Names the variable and its unit; Row = One set of related readings; Cell = A single recorded value; Title = Says what the whole table shows
Headings name variables, rows group related readings, cells hold single values, and the title summarises the whole table.
Multiple choiceLevel 3
29. In a results table, where is the independent variable (the one you deliberately change) usually placed?
- The first (left-hand) columncorrect
- The last column on the right
- Spread across every column
- Only in the table title
By convention the independent variable goes in the first column, with the measured dependent variable in the columns to its right.
Odd one outLevel 3
30. Which is NOT good practice when drawing a results table?
- Decide the table layout after all the data is collectedcorrect
- Give every column a clear heading
- Write the unit in each column heading
- Keep the independent variable in the first column
A careful scientist designs the table before collecting data so readings can be recorded neatly as they come in.

Where these questions come from. Each unit starts as a plan of the concepts it should cover and the difficulty it should span. Questions are written against that plan with AI assistance, then checked by a validator that rejects anything without a single defensible answer, an explanation, or plausible wrong options. How we write questions sets out the whole process, and corrections are fixed in the bank and reach the site and the app the same day.

How you practise

This unit mixes 14 different question formats, so you are recalling and applying rather than recognising the same layout every time.

Build the sentence
Choose all that apply
Fact or fib
Fill the blank
Guess the number
Match the pairs
Multiple choice
Odd one out
Picture question
Put in order
Sort into groups
Spell it
True or false
Type the answer

Practise Data, Graphs and Evidence

131 questions across 22 steps. Start with step one and crawl at your own pace.

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