The society you live is sometimes called the Information Age because
so much data, another word for information, is available to you. You
can easily log onto the Internet and retrieve all kinds of information
that used to be stored in encyclopedias and other books that were
kept in a library. Before the Internet, you needed to have some idea
which book to look into to find the information that you wanted. But
now lots of information is just a few keystrokes away.
Numbers make up a large part of the information that people are interested
in. Let's make a list of some common pieces of data that people are
curious about:
- What is the population of major cities in world like New York,
London and Tokyo?
- How much should a healthy baby weigh at each month of age?
- How many calories are there in foods we eat every day?
- What is the healthy blood pressure for a person my age?
- What is the miles per gallon rating of the car I want to buy?
Let's answer the first question, the population of three major cities.
In 2006 the population of New York was 8,214,426, the population of
London was 7,512,400 and the population of Tokyo was 12,540,000.
Now try to do some comparisons between the population numbers. Put
the cities in order of increasing population, smallest to largest.
Calculate the difference in population between New York and Tokyo.
Imagine if we increased the list to include the population of Chicago,
Los Angeles, Hong Kong and Beijing. All the large population numbers
would be mixed up with English words like you see in the paragraph
above. There must be a better way of showing, or the word that's used
is presenting, data!
Fortunately there is a better way to present data - it's using a
data table which also called tabular data. If you go back to the list
of common pieces of data, you will find that there is a relationship
between two things in each question. Let's see what these relationships
are:
- The name of the city and it's population
- The age of the baby and how much it weighs
- The name of the food and the number of calories
- The age of the person and the healthy blood pressure
- The kind of car and it's miles per gallon rating
If you think about the relationships we've just talked about you
will see that the answer we are looking for is always a number but
sometimes the question is a thing, like the name of the city or a
food. That's okay because you can look up all kinds of numeric information
using a data table.
Now let's put the three pieces of population data into a
data table or tabular format.
|
City
|
Population
|
|
London
|
7,512,400
|
|
New York
|
8,214,426
|
|
Tokyo
|
12,540,000
|
Isn't the tabular format of the population data much easier to understand
and to work with? But there are two ways that this table could be
improved. What piece of information that we had before in the written
paragraph is missing? We don't know the year that population was counted
but since it is the same for each city we will add that in a label
for the table. Every table needs to have a label to identify what
the table contains.
This is a simple table that contains at just three cities but what
if we expanded it to include all the major cities of the world? Then
the table would need to be organized better by putting the cities
in alphabetical order. So a good data table for population would look
like this:
|
City
|
Population
|
|
London
|
8,214,426
|
|
New York
|
7,512,400
|
|
Tokyo
|
12,540,000
|
2006 Population of Major Cities