Day 3: An introduction to graphing

U D M M S C C O U R S E I N E D U C AT I O N & D E V E L O P M E N T 2 0 1 3

N i c h o l a s S p a u l l @ g m a i l . c o m – w w w. n i c s p a u l l . c o m / t e a c h i n g

An introduction to graphing

What is a graph? A graph is a visual representation of information

Why do we use graphs? Often information is easier to understand when in

graphical format. We see patterns, trends and outliers easier than if we had a big data set full of numbers

What kinds of graphs are there? Next slide

Graph interpretation

Some examples of graphs and how to interpret them

Line graphs A line graph can help to show

the relationship between two variables, or the trends in one or more variable over time/space.

In Zambia, what proportion of urban children reach Grade 9? Rural children?

In Swaziland, is the gap between rich and poor larger or smaller than the gap between boys and girls?

Line graphs

http://www.ats.ucla.edu/STAT/stata/library/GraphExamples/code/line4.htm

Has the gap in life expectancy between White and Black males in the US increased or decreased over time?

How much longer did White males live than Black males in 1970?

Stacked area chart

Useful to show how the composition of a whole has changed over time or some other category

What proportion of household income was spent on personal insurance in 1986?

Pie charts

1. Which country has the highest proportion of children reaching higher order reading skills?

2. Which country has the lowest proportion of children that are either illiterate or unenrolled?

Scatter plots

Bar chart – TIMSS 2011 Maths

What is the average mathematics score of quintile 5 children in South Africa? Do they perform better or worse than children in Romania? Lithuania? Morroco?

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Bar Charts – Matric passes in South Africa

Which province has the third largest number of Grade 10 students? Which province has the highest number of matric passes?

Infographics are graphs

A different kind of bar chart… The New York Times…

Enrolment pyramid by age & level of education

1. What proportion of 10 year old children from the poorest 20% of households in Tanzania are enrolled in primary school?

2. What proportion of 13 year old children from the richest 20% of households in South Africa are enrolled in secondary school?

3. What are some of the other features of these two graphs that stand out to you?

Population pyramids

Are Italians in the age range 25-29 more or less likely to be married than unmarried?

Are there more females who are widowed than males that are widowed? (what do you think could explain this? Do females kill their husbands?! )

How will the shape of this population pyramid change in 30 years time? What are the implications?

1. How do population pyramids change shape?

2. Why do you think there was such a strong pyramid shape in these countries in the 1950s? How has it changed and why?

Colour-maps

Is China more or less unequal than India?

Colour-maps

Venn Diagrams

Venn Diagrams Venn diagrams show

the extent to which different sets overlap and to what extent those overlaps are mutually exclusive or mutually inclusive

Tutorial quiz 2, 3 and 4

Go to http://quizstar.4teachers.org/indexs.jsp Enter your username and password There are 3 quizzes in this section

Graphs (STACKED BAR GRAPHS) Graphs (POPULATION PYRAMIDS) Graphs (SCATTER PLOTS)

I would recommend completing them in this order If you have any questions raise your hand and I will come and

help you For those not already registered you can register as a student

on http://quizstar.4teachers.org/indexs.jsp and then search for my class  ”UDM Msc Education” anyone can join the class