Understanding picture and bar graphs

0:00- What do you see here are two different ways of looking at the same information. So, for example, if I were to ask you, and you could look at either this graph on the left or this graph on the right, what type of squirrel do they find the most of at the park?

0:19What would your answer be? Well, the way that you would try to answer that, let's say you were to look at this graph on the left, which is a picture graph. You might say, "Where does that name come from?" Well, it's using pictures. And these pictures usually are some type of symbol, or in this case, an actual picture of a squirrel that shows you the things that we're counting.

0:38Now, before you even just count the picture graph, the pictures in the picture graph, it's important to look at the key here and make sure that you know what each squirrel picture. They almost look like cats here. What each of these squirrel pictures represent here, each squirrel represents one squirrel, so it's pretty straightforward, but it could have been two squirrels or three squirrels, or four and a half squirrels, which would've been very strange, but it's one squirrel.

1:03So if you wanted to know which one has the most, and I guess it would've been the most, regardless of what this key said, even if it was two squirrels, you can see just by looking at it that you see the most gray squirrels here. There's the most number of these little squirrel pictures.

1:16We can actually know exactly how many gray squirrels there are. There are 1, 2, 3, 4, 5, 6, 7, 8 of these pictures. Each of them represent one squirrel, so there are eight gray squirrels. Now, we could have also used this graph at the right, and this is called a bar graph.

1:35Why? Because you have these bars to show how much of each type of squirrel you have, and so we can make sure we can confirm that the gray squirrels right over here. This is also showing that you have eight, and with a bar graph, this one has it nicely numbered, where we see that each line increases by one.

1:54We go from 1, 2, 3, 4, 5, 6, 7, 8, 9. Sometimes it's not labeled as neatly, and sometimes each of these vertical lines might represent two or three or four. So it's always good to make sure, but this one's pretty straightforward. So we can see here there are eight gray squirrels.

2:12Now these can also be useful for making comparisons. So, for example, if I were to say how many more fox squirrels were found at the park than red squirrels? Well, you could look at either of these. Let's start with the bar graph here. We could see the red squirrels.

2:27There's five. The fox squirrels has six, so there's one more. There's one more fox squirrel than red squirrel. You can see that here. The red squirrel fives, fox squirrel. The red (chuckles) There are five red squirrels, and then you can see there are six fox squirrels.

2:43You could think of this one as the one that goes above and beyond the number of red squirrels we have. So both picture and bar graphs can be good ways of thinking of the quantities. You see, they're good for making comparisons. They're good for figuring out just how many of something you see or what's the difference, or even the total of different categories.

3:06Here, it's the squirrel types. Now, it's also important to realize what this is not going to tell you. This isn't necessarily going to even tell you the color of the squirrels. You might say, "Oh look, this picture graph looks like this squirrel. Is this gray/blue color?"

3:18No, you can't just assume how it's drawn is actually what it is. It's just a symbol. For example, I'm guessing that a red squirrel is more reddish, and a gray squirrel, and maybe a gray squirrel is more grayish. But this doesn't tell you what they look like. This doesn't tell you how hard it was to collect the data.

3:33You don't know how long it took. You don't know anything else about the squirrel's behavior, what they might eat, et cetera. You just know how many of each type of squirrel was found at the park.