ACARA Digital Technologies Years 7–8 — Acquiring and Storing Data Hangman

The 70 key terms

1data

Raw facts and values, like names or scores. When data is organised so it has meaning, it becomes information, like a table showing each class's average score.

2primary data vs secondary data

Primary data is data you collect yourself, like a survey. Secondary data was collected by someone else, like data from a website or database.

3Quantitative data

Numerical data that can be counted (discrete, like number of students) or measured (continuous, like temperature) and used in calculations, such as ages, scores and temperatures.

4Qualitative data

Descriptive data such as opinions, comments and experiences, often from open-ended responses or interviews. It is not measured as numbers, and is sorted into categories and descriptions.

5data requirements

A list of the data items, types, sources and amount needed to answer a research question, such as the variables, primary or secondary source, time period and sample size.

6essential data

Data a system cannot do its purpose without. If the system could still work with it left out, the data is optional and does not need to be collected.

7survey

A survey collects data by asking everyone the same clear questions, such as closed or open questions on an online form, so the answers can be counted and compared.

8unbiased survey question

A survey question that is neutral, asks about one thing only, and gives answer choices that cover every honest response, so it does not push people toward a particular answer.

9closed vs open question

A closed question gives fixed choices to pick from, like multiple choice or a rating scale. An open question lets people write their own answer, so it is harder to count.

10sample

The group of people you actually ask in a survey. A bigger, fairer sample gives more trustworthy data than asking only a few friends.

11biased data

Data that unfairly favours one view or group because of how it was collected or selected, e.g. sampling bias, leading questions or missing groups.

12Form responses sheet

A spreadsheet linked to an online form. Each submitted response becomes a new row, each question is a column, and a timestamp column records when it was sent, giving data ready to use.

13consistent data entry

Typing each survey answer in its own cell, one row per person, using the same spelling and format every time (Yes, not yes or Y), and leaving the cell blank if there is no answer.

14sensor

An input device that measures a physical quantity, such as heat or light, from the environment and sends the readings to a computer or microprocessor.

15temperature sensor

An input device that measures how hot or cold something is. Used in central heating, ovens, greenhouses and weather stations.

16moisture sensor

An input device that measures the amount of water in a solid material such as soil. Used in automatic plant watering and farming. Not the same as a humidity sensor, which measures air.

17light sensor

An input device that measures how bright the light is and sends the light level to a computer. Used in automatic street lights, screen brightness and greenhouses.

18accelerometer

A sensor that measures acceleration (change in speed or direction) and tilt. Used for phone screen rotation, step counters and car airbag impact detection.

19data first, then sensor

Each sensor captures one type of data, so identify the data first (e.g. moisture in soil, humidity in air), then name the sensor that measures it.

20time-series data

Data recorded repeatedly over time, each value with a timestamp, usually at regular intervals, so you can see how values change and spot trends and seasonal patterns.

21input.temperature()

A micro:bit block that returns the temperature reading in degrees Celsius as a number. You can show it with basic.showNumber() or store it in a variable.

22datalogger.log()

Saves one row of named sensor readings, with a timestamp, in the micro:bit data log. Each call adds a new row, so use it in a loop to record readings over time.

23MY_DATA.HTM

The file on the MICROBIT USB drive that opens the data log. Use its Download CSV button, then open the CSV in a spreadsheet and check the column headings.

24outlier

A reading far from the rest or impossible, like -999. It may mean the sensor is faulty or in the wrong place, so check it before you use it.

25open data

Datasets, such as government statistics, that anyone can download from a portal. A licence says how you may reuse them, and you must credit the source.

26authentic data

Real data collected by a trusted organisation and kept in a large repository; check its publisher, date and relevance to your question.

27search filter

A setting in a data repository, such as topic, date range or file format, that narrows the results so you find and download only the data you need. Check the metadata first.

28file format

The way a dataset's data is structured and stored in a file, such as CSV, XLSX, JSON or XML. Choose the format that suits the software you will open it in.

29CSV 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.

30data generator

A tool that makes random sample data, with fields and rows you choose, to practise with when real data is not available. You can export it to a spreadsheet. It is test data, not real data.

31spreadsheet

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.

33Click 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.

34header 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.

35data 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.

36Raw_Data

A short, clear worksheet tab name that describes what the sheet holds. Use one consistent style with no spaces, and keep raw data on a separate tab from analysis, such as Summary.

37string

Text made of a sequence of characters (single letters, digits or symbols), written in quotes, like 'Sam' or '0412345678'. Phone numbers are strings.

38integer

A whole number with no decimal part, positive or negative, used for counts such as the number of students in a class (e.g. 25, 0 or -3).

39float

A floating point number is a number with a decimal part, such as 1.75 or 19.95. It is used for measurements like height and for money, unlike an integer, which has no decimals.

40Date/Time

A data type that stores a calendar date and/or time of day, such as 25/03/2025 or 14:30, so values can be sorted in order and used to calculate the duration between two dates.

41data type

Pick the data type by what you will do with the value: calculate (number), sort by date (date/time), test true or false (Boolean). Postcodes are text, not numbers, as you never do maths on them.

42cell 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.

44fill 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.

46=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.

47=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.

48=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.

49Sort

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.

50filter

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.

51=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.

52=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.

53accuracy

Data is accurate when it is correct and free from errors, so it matches the real-world fact it records. Typos, faulty measurements and out-of-date values make data inaccurate.

54clean data

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

55raw data copy

An untouched copy of the original data, made by duplicating the worksheet or using Save As before cleaning, so you clean only the copy and never lose the original.

56ISBLANK

A spreadsheet function that checks a cell. It returns TRUE if the cell is empty and FALSE if it holds data, so it works as an existence check. COUNTBLANK counts empty cells in a range.

57missing value

An empty cell where data should be. Find it with a filter for blanks, then delete the row, fill it from a reliable source or exclude it so AVERAGE and COUNT are not distorted.

58=COUNTIF($A$2:$A$100,A2)>1

Gives TRUE when the value in A2 appears more than once in column A. Put it in a helper column to flag duplicate rows, then filter for TRUE.

59Remove Duplicates

A spreadsheet tool that deletes rows repeating the same values in the columns you choose to compare, keeping the first match. Always keep a copy of the raw data first.

60=AND(B2>=0,B2<=100)

A range check formula. It returns TRUE only if the value in B2 is at least the minimum (0) and at most the maximum (100), so boundary values pass and anything outside is rejected.

61=IF(OR(B2<0,B2>100),"Check","OK")

Shows Check if B2 is below 0 or above 100, otherwise OK. OR needs just one true test, so it catches both ends. AND would never work because no value is both below 0 and above 100.

62ISNUMBER

A function that tests whether a cell value is a number. It returns TRUE for a number and FALSE for text, so it works as a type check. ISTEXT does the same job for text.

63=VALUE(A2)

Converts text that looks like a number, such as '45' stored as text, into a true number so it can be added, averaged and sorted correctly. Left-aligned numbers are a warning sign.

64Conditional formatting

A spreadsheet tool that changes a cell's colour or icon automatically when its value meets a rule, so highs, lows and outliers stand out.

65=TRIM(A2)

A text function that returns a tidy copy of the text in A2 with extra spaces removed. UPPER, LOWER and PROPER work the same way to fix capitals, e.g. =PROPER(A2) gives Mia Chen.

66Find and Replace

A spreadsheet tool (Ctrl+H) that finds every cell with one spelling and changes them all to the correct spelling in one step, like turning Sydeny into Sydney.

67validation

An automatic check that data is reasonable and in the right form when entered. It blocks bad data early, but it cannot prove the data is true (a valid age of 15 could still be wrong).

68validation check

A test that an entry is sensible. Types include presence, data type, range, length, format and list. Each one tests a different property of the entry.

69Data > Data validation > Whole number between

A rule that only lets a cell accept a number between a minimum and maximum, like age 11 to 14. Numbers outside the range are rejected. Use Decimal for numbers with parts.

70List validation

A rule that lets a cell accept only items from a set list, shown as a drop-down. Items can be typed in or taken from a range of cells, which keeps spelling consistent.

71Error alert

A message that pops up when someone enters data that breaks a validation rule. It can Stop the entry, Warn about it, or give Information, and a good message explains how to fix it.

72=COUNTIF(D2:D100,"Check")

A quality summary counts problems with formulas like this one. It counts cells flagged Check. COUNTBLANK counts empty cells. Each problem count should reach 0 after cleaning.

73cleaning log

A record of each data problem found, the fix applied and how many rows were affected, so every change, including deleted rows, can be explained and checked.