Data collection and display vocabulary

Here are some big words people use when they show data.

Frequency means how many times a value shows up in the data. If three children picked red, the frequency of red is 3.

A frequency table is a chart that lists each value and shows its frequency next to it. It helps you see the data without counting over and over.

A histogram is a kind of graph made of bars that touch each other. It shows how data is spread out. The bars group numbers into ranges.

A frequency polygon looks like a line graph, but it uses ranges of numbers to show lots of data.

Want to be a data collector? You can do your own survey.

First, decide what data you want to study. Pick something you can count, like how many buttons are on coats in your class.

Next, ask if your data is discrete or continuous. Discrete data is counted, like the number of buttons. Continuous data is measured, like the length of a leaf.

Then, ask each person your question and record the answers. You can use tally marks to keep track.

After that, count the tally marks to find the frequency of each answer. Put the results in a frequency table.

Finally, draw a bar chart or pictogram to show what you found. Give it a title and label the axes so other people can read it.

A graph has two lines called axes. One goes across the bottom and one goes up the side.

The line across the bottom is the horizontal axis. It is labeled with what the data is about. It might say days of the week or names of fruits.

The line going up the side is the vertical axis. It is labeled with how many, like the number of children or the height in centimeters.

Each axis needs a label so people know what it shows. The scale on the axis tells you what each step on the line is worth, like counting by 2s or by 5s.

A good graph also has a title. The title tells you what the whole graph is about.

A pie chart is a circle cut into slices, like a real pie. Each slice shows a part of the whole.

Pie charts help you compare parts of a total. If 4 children like dogs, 3 like cats, and 5 like fish, you draw a slice for each group. The fish slice is the biggest because fish has the most children.

Every slice together makes the whole pie. The whole pie stands for all the answers you collected.

To read a pie chart, look for the biggest slice first. That is the most popular choice. Then look for the smallest slice. That is the least popular choice.

Remember, a pie chart shows parts of one whole group. If your data does not add up to a whole, a bar chart might be a better pick.

A graph is a picture that shows how something changes or compares.

First, draw the x axis. That is the flat line across the bottom. It is the horizontal axis.

Next, draw the y axis. That is the line that goes up the side. It is the vertical axis.

Then mark numbers or names along each axis. These marks are the scale. The scale must go up in equal steps, like 1, 2, 3, 4.

After that, put a label on each axis. The label says what the axis shows. Add a title at the top too.

Now you can plot your points. Each point sits above its x value and across from its y value.