Introduction to Junior Statistics
Data and the PPDAC cycle
Name: Emily Apatu
Data
What does data look like? Results and graphs of and simple questions of surveys.

We need to think about how we collect the data, what question we ask, what answers people might give, and how to record the answers.

We also need to think about how many people to ask. This is called our sample size.

There are several ways to collect data:
By carrying out a survey
This is when you ask people some questions.
By doing an experiment
This is when you test or measure people or objects, like in science.
By taking a census.
This is where you ask every person in the country a bunch of questions.

Survey Exercise:
Ask 4 people the following questions, and record the information in the table below.

1 How old are you?
2 Are you male or female?
3 What did you eat for dinner last night?
4 How many songs have you listened to today?
Student
Age
Gender
Dinner
Songs
1
13
Female
Pork
3
2
13
Female
Pizza
1
3
13
Female
Pork
2
4
13
Female
Pork
1

Asking students questions like this is called a survey.
Describe what a survey is, in your own words.
A survey is a simple few questions of a sample of people.

Experiment Exercise:
Take the measurements below from 4 people, and record the information in the table below.

Student
Length of thumb
Length of little finger
1
7cm
7cm
2
6.5cm
6.5cm
3
6cm
6cm
4
5.5cm
5.5cm

Measuring students like this is called an experiment.

Describe what an experiment is, in your own words.
An experiment is a measure of students of people weather it was like your favourite lollies or recording the height of different people.
Census Exercise:
A census is where we collect information from every person living in New Zealand. We do this every 4 years.

The government gets information such as:
How many young people we have in NZ
How many elderly people we have in NZ
How many people live in one house
How many hours people work each week
The government uses this information to help it decide things like:
Where to build new schools (if there are a lot of young children in one area, they will need a school)
How many hospital do we need
Do families need more financial or medical assistance

Describe what a census is, in your own words.
A census is an official count or survey for people around New Zealand to fill out the form to record the census around the country for the population or how many people work each week to use this information to help the Government to decide things to build new schools if there are a lot more children.
Data Type Exercise:
Look at your data on pages 3 and 4.
Think about the answers – are they a measurement (e.g. height), a count (e.g. how many people have a cell phone in our class), or a group (e.g. ethnic or cultural group).
Circle the data type for each variable in the table below.
Variable
Type of data
Age
Measurement
Counting
Group or category
Gender
Measurement
Counting
Group or category
Dinner
Measurement
Counting
Group or category
Songs
Measurement
Counting
Group or category
Length of thumb
Measurement
Counting
Group or category
Length of little finger
Measurement
Counting
Group or category
Different data
There are 4 types that we need to tell the difference between:
Summary (Univariate data)
Relationship (Bivariate data)
Comparison (Multivariate data)
Time series (data collected over time)
We need to know what investigation problem is, because the data, graphs and calculations we do for analysis, and the conclusions will be different for each data type.

Variable
A variable is a collection of values (measurements, counts or groups) that are all about the same thing.

Example
If we measure the height of all students in our class, then the height is the variable and it has a lot of values (or measurements).
Problem

Summary Problems
This has one variable, and could be a measurement or count.
For example: height.

The investigation problem looks