Data quality: relevance

Name:

Date:

Class:

Quick Questions

Shade in the A or B circle for each question.

1. A school wants to know how many students use the canteen. Which data is relevant?

A Canteen purchase records per student

B Students' favourite football teams

2. True or false: Relevance means the data relates directly to the question or purpose it is used for.

A True

B False

3. A survey about bus use includes a field for each student's shoe size. What is the problem?

A The shoe size field improves the relevance of the data

B The shoe size field is an extra unneeded field that is not relevant

4. A council wants to know what local teenagers think of a new skate park. Which group should it survey?

A Teenagers who live in the local area

B Adults living in another state

5. Which statement about relevance is correct?

A Relevance has no effect on the quality of information

B Relevance is a characteristic of information that affects its quality

Match the Pairs

Draw a line connecting each item on the left to its match on the right.

Left column		Right column
1relevant data		AA column of data that does not help answer the question, such as shoe size in a study of exam results
2irrelevant field		BQuestion: Average Year 10 maths mark? Keep: Student, Year, MathsMark
3Data from the wrong population is not relevant to the question being asked		CData that relates directly to the question or purpose it is being used for
4Relevance is a characteristic of information: only keep the fields that answer the question		DQuestion: Do Year 11 students sleep enough? Data: survey of Year 7 students
5Purpose: Find the most popular canteen food. Data: students' bus routes and home postcodes		EThe data is from the wrong population. Use responses from VCE students so the data is relevant to the question.
6Question: How many hours do VCE students study? Data: 500 responses from primary school students		FThe data does not relate to the purpose. Bus routes and postcodes are irrelevant. Collect canteen purchase or food preference data instead.

Definitions

relevant data

Fill in the Blanks

Complete each line of code by filling in the missing parts.

// Average score of Year 10 students SELECT AVG(mark) FROM marks _____ year = 10;

// Show rainfall for each suburb SELECT suburb, ________ FROM weather;

=_________(B2:B30,"Year 10",C2:C30)

// Only keep adult respondents IF age __ 18 THEN KEEP record

// Attendance for Year 7 students only SELECT * FROM students WHERE year = _;

Spot the Error

Shade in the letter of the line that contains an error.

Question 1

A SELECT AVG(ShoeSize)

B FROM Year10Results

C -- Goal: Year 10 maths average

Question 2

A GOAL: Year 10 maths average

B SET rows ← Students

C KEEP rows WHERE Year = 7

D SHOW average of MathsMark

Question 3

A GOAL: Students' lunch choices

B ASK ← parents of students

C QUESTION: Favourite lunch?

Question 4

A SELECT Name, Email, Weight

B FROM Students

C -- Goal: newsletter mailing list

Question 5

A GOAL: Geelong rain in 2023

B LOAD file: BoM_rain.csv

C FILTER Town = Geelong

D FILTER Year = 1998

Answer Key

Data quality: relevance

Section A: Quick Questions

A — Canteen purchase records per student

A — True

B — The shoe size field is an extra unneeded field that is not relevant

A — Teenagers who live in the local area

B — Relevance is a characteristic of information that affects its quality

Section B: Match the Pairs

relevant data → Data that relates directly to the question or purpose it is being used for

irrelevant field → A column of data that does not help answer the question, such as shoe size in a study of exam results

Data from the wrong population is not relevant to the question being asked → Question: Do Year 11 students sleep enough? Data: survey of Year 7 students

Relevance is a characteristic of information: only keep the fields that answer the question → Question: Average Year 10 maths mark? Keep: Student, Year, MathsMark

Purpose: Find the most popular canteen food. Data: students' bus routes and home postcodes → The data does not relate to the purpose. Bus routes and postcodes are irrelevant. Collect canteen purchase or food preference data instead.

Question: How many hours do VCE students study? Data: 500 responses from primary school students → The data is from the wrong population. Use responses from VCE students so the data is relevant to the question.

Section C: Definitions

relevant data — Data that relates directly to the question or purpose it is used for. Unneeded fields or data from the wrong population are not relevant, so they lower the quality of the information.

Section D: Fill in the Blanks

// Average score of Year 10 students
SELECT AVG(mark) FROM marks WHERE year = 10;

// Show rainfall for each suburb
SELECT suburb, rainfall FROM weather;

=AVERAGEIF(B2:B30,"Year 10",C2:C30)

// Only keep adult respondents
IF age >= 18 THEN KEEP record

// Attendance for Year 7 students only
SELECT * FROM students WHERE year = 7;

Section E: Spot the Error

A — The goal is the Year 10 maths average, so the field averaged must be MathsMark. ShoeSize is not relevant to the question. It should be SELECT AVG(MathsMark).

C — The goal is about Year 10, but this line keeps Year 7 students. That is the wrong population, so the data is not relevant. It should be KEEP rows WHERE Year = 10.

B — The goal is what students choose for lunch, so the survey must go to students. Asking parents gives data from the wrong population. It should be ASK ← enrolled students.

A — A newsletter mailing list only needs names and email addresses. Weight is an extra, unneeded field that is not relevant to the purpose. It should be SELECT Name, Email.

D — The goal is rainfall in 2023, but this filter keeps 1998 data. Data from the wrong time period is not relevant. It should be FILTER Year = 2023.