ACARA Digital Technologies Years 7–8 — Analysing and Visualising Data Hangman

The 48 key terms

1data question

A clear question that can be answered with numbers you can collect or already have, such as how many, how much or what changed over time.

2spreadsheet

A grid of columns (letters, running down) and rows (numbers, running across). A cell is where a column and row meet, like B3. Each worksheet holds one grid.

4Click a cell, type, press Enter

To store data, click a cell, type your value, then press Enter to save it. Tab saves it and moves right. Text lines up left and numbers line up right.

5numeric data vs text data

Numeric data is numbers you can calculate with, like 12 or 3.5. Text data is words and characters, like cat or a phone number, which you never add up or average.

6data table

A grid that organises data. Each column has one heading, and each row holds one record, like one student or one pet. There are no blank rows.

7header label

A label in the first row or column that names the data below or beside it. Use one per column, add units like Height_cm, and keep capitalisation consistent.

8CSV file

A plain text file that stores table data with commas between the values. A spreadsheet can open it and show the data in rows and columns.

9clean data

Finding and fixing mistakes in data, like typos, spelling variations, duplicate rows, missing values and impossible values, so the results are correct.

12=SUM(B2:B10)

A formula that adds up all the numbers in a range of cells. The colon means 'from B2 to B10'. The AutoSum button can type it for you.

13=COUNT(B2:B10)

A spreadsheet formula that counts how many cells in the range B2 to B10 contain numbers. It ignores cells with text or empty cells.

14=COUNTA(A2:A100)

COUNTA counts every cell in a range that is not empty, including text. Use it to count survey responses. COUNT only counts numbers.

15=AVERAGE(B2:B10)

A spreadsheet function that adds up the numbers in cells B2 to B10 and divides by how many there are, to find the mean (the typical value). It is not the total.

16=MIN(range) and =MAX(range)

MIN finds the smallest (lowest) value in a range of cells and MAX finds the largest (highest) value. For example, =MAX(B2:B10) shows the top score in cells B2 to B10.

17SUM COUNT AVERAGE MIN MAX

Match the key words in a question to a function: total is SUM, how many is COUNT, typical is AVERAGE, lowest is MIN, highest is MAX.

18=MAX(B2:B30)-MIN(B2:B30)

Range is the largest value minus the smallest. It shows how spread out data is, but one outlier can stretch it. Not the same as a cell range like B2:B30.

19fill handle

The small square at a cell's corner. Drag it down to copy a formula to the cells below. The cell references change row by row, so B2 becomes B3.

21=ROUND(number, digits)

Rounds a number to a set number of decimal places. Use 1 for one decimal place or 0 for a whole number, e.g. =ROUND(AVERAGE(B2:B9),1). It changes the value itself, not just how it looks.

22cell formatting

Changing how a cell looks, such as currency, decimal places, bold or column width, without changing the value stored inside it. For example, 5 can show as $5.00.

23status bar

The bar at the bottom of a spreadsheet. Select a range of number cells to see their sum, average and count, then compare with your formula. Right-click it to choose what shows.

24Sort

Sorting puts the rows of a table in order using the values in one column, like A to Z or smallest to largest, and keeps each row together.

25filter

A filter shows only the rows that match a value you choose and hides the other rows. The hidden rows are not deleted. Clear the filter to see them all again.

26Number Filter

A filter that keeps only the rows where a number meets a condition, such as greater than a value or between two values. The other rows are hidden, not deleted.

27filter then sort

First filter the table to keep only one group, then sort a number column from largest to smallest. The top row is the highest value and the bottom row is the lowest in that group.

28=IF(test, value_if_true, value_if_false)

Checks a condition, like B2>=50, and shows one result if it is true and another if it is false. Text results go in quotes, and you can copy it down a column.

29=COUNTIF(C2:C50,"Yes")

COUNTIF counts the cells in a range that meet a condition. SUMIF works the same way but adds up the values that meet it. Example: count every 'Yes' in C2:C50.

31=(C2-B2)/B2

Percentage change: (new - old) / old, formatted as a percentage. A positive result is a rise, a negative result is a fall. Use it for year-on-year growth.

32=MEDIAN(B2:B30)

Returns the middle value of the numbers in B2:B30 once ordered. With an even count it averages the middle two. You do not need to sort the cells first.

33mean vs median

An outlier drags the mean towards it but barely moves the median. If the two differ a lot, the data is skewed, so the median is usually the fairer typical value to report.

34pattern, trend, outlier

Look for patterns and trends in data, like highest, lowest, going up or down. An outlier is a value that stands out from the rest. Compare groups to see differences.

35Investigate the outlier

Check if an outlier is a typing error or a real extreme value. Fix errors, keep real values, and compare results with and without it. Never delete data just to fit your story.

36=AVERAGE(B2:B4)

A moving average. It averages the latest 3 values. Copy it down and the range slides by one row each time, smoothing the ups and downs to show the trend.

37Choosing the right chart

Pick the chart that matches your question: a bar chart to compare categories, a line chart for change over time, and a pie chart for parts of a whole.

38bar chart

A chart that uses bars to compare amounts in different categories. Select the labels and values, then choose Insert chart. Column charts have upright bars; bar charts lie sideways.

39line chart

A chart that joins points with a line to show how a value changes over time. Time goes along the bottom axis, so you can see if the trend goes up or down.

40pie chart

A circle chart split into slices. Each slice shows how big one part is compared with the whole, often as a percentage. All the slices add up to 100%.

41scatter graph

A chart that plots each record as a point using two number columns, one on the x axis and one on the y axis, to show whether two things are related.

42Change Chart Type

A chart option (right-click the chart) that switches it to another type, like column to line, using the same data so you do not have to enter it again.

43Chart Elements

The button beside a chart that adds or edits its title, axis titles (with units), legend and data labels, so anyone reading the chart knows what it shows.

44Title, axis labels and legend

The parts that help a viewer read a chart: the title says the topic, axis labels name the data and units, the legend explains colours.

45Add series

Adds a second set of values to a chart so two groups can be compared on the same axes, with a legend to tell them apart.

46misleading chart

A chart whose design, like a cut-off axis, 3D effects or a cherry-picked range, makes the data look different from what it truly shows.

47Trendline

A straight or curved line fitted to the points on a chart. It shows the overall direction of the data, such as going up or down. Add it with Add Chart Element > Trendline.

48prediction

Extending a trend past the known data, such as running a trendline forward, to estimate a future value. It is an estimate, not a certainty, and gets less reliable the further ahead you go.

49reliability

How much you can trust a prediction. It drops with small samples, outliers and predicting far beyond your data, so always state how uncertain the prediction is.

50correlation is not causation

Two things can rise or fall together without one causing the other. A trend shows a relationship, not the reason, so a hidden third factor may explain both.

51conclusion

A statement that answers a question using evidence from the data, such as numbers. It should only say what the data shows and stay within the data's limits.

52Sales rose from 40 to 65

A trend statement says what changed, which way it went and the numbers that show it, plus a limit or reason such as 'because' or 'might'.

53question > prepare > analyse > chart > conclude

The order of a data investigation: ask a question, prepare the data, use formulas and sort or filter, chart it, then conclude, predict and report limits.