Booklet 2: Data Analysis

Question 1

Measure of central tendency definition

Answer 1

An average of a data set

Question 2

Mean definition

Answer 2

• The score commonly known as the average
• To calculate, you add all the numbers in the data set together and divide by the total amount of results

Question 3

Median definition

Answer 3

• The middle value when raw data is placed in order from smallest to largest
• It is not affected by extreme values as they are marginalised

Question 4

Mode definition

Answer 4

• The value or event that occurs most frequently
• This measurement is a basic measure of central tendency

Question 5

Strength of the Mean

Answer 5

• POINT - All of the data is used to calculate the answer
• COMMENT - Therefore it is an accurate representation of the data

Question 6

Weakness of the Mean

Answer 6

• POINT - Extreme scores can distort the value
• COMMENT - Therefore it is not an appropriate measure of central tendency if our data set is skewed

Question 7

Strength of the Median

Answer 7

• POINT - Extreme scores do not distort the value
• COMMENT - Therefore it is a robust measure of central tendency if our data set is skewed by extreme values

Question 8

Weakness of the Median

Answer 8

• POINT - It is difficult and time consuming to calculate with a large data set
• POINT - It is a less representative measure of central tendency because it does not depend on all the items in the data

Question 9

Strength of the Mode

Answer 9

• POINT - It is the only measure of central tendency we can use when the data is not numerical
• COMMENT - Therefore it allows for analysis of the most commonly occurring category

Question 10

Weakness of the Mode

Answer 10

• POINT - This measure of central tendency may not accurately reflect the data
• COMMENT - Therefore if there is no most popular answer, this measure of central tendency is effectively useless

Question 11

What is Discrete data

Answer 11

Data that can be placed into separate categories

Question 12

What is Continuous Data

Answer 12

Data that cannot be placed into distinct categories and can be presented on a number line

Question 13

What are the 5 graphs you need to know

Answer 13

• Bar Charts
• Pie Charts
• Histograms
• Line Graphs
• Scatter Graphs

Question 14

Which of the graphs represent Discrete data

Answer 14

• Bar Charts
• Pie Charts

Question 15

Which of the graphs presents Continuous data

Answer 15

• Histograms
• Line Graph
• Scatter Graph

Question 16

What is the criteria for drawing a Bar Chart

Answer 16

• Used for discrete data
• Columns do not touch
• Useful for comparing groups of data
• The mean/frequency is on the Y axis
• The category is on the X axis
• Labels on each axis
• Title

Question 17

What is the criteria for drawing a Pie Chart

Answer 17

• Used for discrete data
• Shows relative contribution to overall total
• Used for 6 categories or fewer
• Useful when data is showing a percentage

Question 18

What is the criteria for drawing a Line Graph

Answer 18

• Used for continuous data
• Used for comparing 2 or more conditions
• Good for looking at changes over time
• Continuous scale is on the X axis
• Frequency/measurement is on the Y axis
• Data points are connected with a straight line
• Labels at the end of the lines

Question 19

What is the criteria for drawing a Scatter Diagram

Answer 19

• Used for continuous data
• Used for measuring the relationship between two variables
• Data from one variable is presented on the X axis and the other variable on the Y axis
• Shows a positive, negative or no correlation

Question 20

What is the criteria for drawing a Histogram

Answer 20

• Used for continuous data
• Columns touch
• The area of the columns shows the frequency
• The frequency density is on the Y axis
• The continuous scale is on the X axis
• Requires class boundaries, class width and frequency density

Question 21

How do you calculate frequency density

Answer 21

Frequency Density = Frequency / Class Width

Question 22

Structure for Exam Q:
“Outline a conclusion from the table”

Answer 22

1. State a finding using raw data
2. Explain what this data means in the context of the study
3. Making an inference as to why

Question 23

Structure for Exam Q:
“Outline a finding from the table”

Answer 23

1. State a simple finding from the table or graph including the numbers if possible
2. Make sure it is in context of the data in the question