Reading Scatter Plots and Understanding Correlations.

__a comment to this post__, please discuss each of the graphs below. Be sure to address the questions under each graph. Please don't copy the questions or number your answers, rather, you should write a paragraph or two in complete sentences so your reader knows what you are talking about. Be sure to sign in as "anonymous" but put your first name and last initial in the post so I know to whom to give the credit. If you have any questions please e-mail me. Review the "how to e-mail a teacher" post on my blog before you send your e-mail.(click on the graphs to enlarge)

I strongly suggest you write the comment in Word or another program and then copy and paste it into the comment section below. This way, if the comment doesn't go through or is accidentally deleted you'll have a record of your work. Please also remember that I have to approve all comments, so it may take a while for it to show up on the blog. You don't need to resubmit it over and over.

What can we see from the above scatter plot of hair length vs. height? Is there a correlation? How strong is it? If so, is it positive or negative; strong or weak? What information about the students in our class does this graph give you? Are there a few "outliers" or extreme data points that seem unusual? If you throw them out of the data set what does the correlation look like? What other information would be helpful to interpret the data?

Above is the data we collected about our shoe sizes vs our heights. Can you see a relationship? Is there a correlation? If so, is it positive or negative? How strong is it? What about the person who is 160cm tall and has a foot that is 9cm long? Look at a ruler to see what 9cm looks like and explain what you think happened to cause that outlier. Does shoe size cause height to change? Does height cause shoe size to change? Does correlation imply causality - explain why or why not.

## 14 comments:

The first graph that I see is comparing the hair length with the height of an individual. The graph is not so accurate because the data is increasing and decreasing in terms of hair length. In my opinion the hair lenth has nothing to do with someone's height, they don't connect in any way because I see no pattern. Mean while the other graph compares the hair length with the shoe size in a more accurate manner. The reason being is because the height increases as the shoe size increases this proofs that height and shoe size really connect in many ways. I think that with this being said shoe size connects more with getting a better data than hair length.I can say that their was probably one outlier at the beginning of the graph because the i can see how an individual with a small shoe size (8cm) had a height that was suppose to be connected with those who had a shoe size of about 20-25 cm long. From the first data I would say that their was a correlation because their was no relationship among hair length and height.The information was weak because it wasn't good enough to say that shoe size has a lot to do with hair length. Although the second experiment was the whole opposite.

- Marlene Vences

Please be sure to address all the questions I ask in the post. Break it up into paragraphs as needed to make your answer more clear.

The hair length vs. height scatter plot shows a zero correlation. That correlation is strong because all the data is located in random areas showing no positive or negative correlation relation. From the graph, I learned hair lengths and heights have nothing in common, although there seems to be an average between 150 and 170 cm. There are several outliers whom, if were removed, would leave the results almost in a straight line. Finding out what causes length of hair, such as genetics, would be a way to see if different races had different average hair lengths.

Shoe size is increasing with height in this graph. Yes, there is a positive correlation, which is extremely strong. The person with the height of 160 cm and 9 cm foot size, most likely, there was an error when entering the information. Having small feet would be reasonable if the person was a child; but we have all teenagers in our class. I feel the graph does not provide enough evidence to link if shoe sizes makes a person taller. Overall, the taller the person, the larger their feet were. This correlation does imply causality because the graph is persistent.

Marilyn V. Rodriguez

In the first graphs it shows no correlation. No similar pattern seems to be graphed. For what I think, I believe its a negativeas well as weak. The graphs show no similarity between them them. Their is no correlation between hair lenght and height, The reason why this might be is because everyone is different, everyone has diffrent hair styles. Their can be tall bald guys as well as short people with tons of hair, and so on. Their's no actual evidence or prove that hair lenth and height and related in any way.

In the graph collected from our class their is a correlation. That graph shows that the taller you are the bigger your feet is. This graph is strong as well as positive. The person that wrote down 9cm probably got confused. 9cm is aabout 8.5 inches. This person in real life is a 8.5-9 in shoe size. This person should had put 20-23cm. If this individual's real shoe size is 9cm then its abnormal because it would turn out about 3.5 in. Only a baby will have that type of feet. Overall in our class case height does affect shoe size.

Noa Z. 4

In the hair length and height graph you can see that the charts scatter plot consists basically of a straight line. This means that the too variables are have no correlation. It's is neither strong or weak nor negative or positive. This graph shows u that every student in class can not be put in the same category when it comes to hair length and height. You can prove that because there are many outliers. If u were to take away the outliers the graph would be a straight line.

On the other hand if you were to look at the data chart for height and shoe size u can see how the scatter plots make a sort of inclined plane. That shows that there is a correlation because as the height increases so does the shoe size. The amount of incline on the chart shows that it is a strong correlation in the positive direction. I believe that the outlier that is 160 cm tall and has a foot size of 9 cm was most likely a miscalculation and instead of putting 19 cm they put 8 cm.

I do not think that a height creates a certain shoe size or vice versa but that there is an calculation that states that people with a certain height have have an approximate shoe size but not an exact one. Everyone is different so not everyone is exactly the same.

Rosa O.

Looking at the graph between the interactions of hair and height you can see numerous combinations of hair and length’s erratic results. By looking at this graph I think it is very obvious that there is no relationship between a persons shoe size and hair length. This graph to me only tells me that we are all of different sizes. I think that this experiment has to be looked at from a Developmental psychologist point of view. If we where to have done measurements on participants all in the same age group, whom have never had hair cuts, or taken any drugs that could have stunted their growth then I believe the results would have been tremendously different then now and could possibly have shown some sort of relationship between the hair length and shoe size.

~Letty Bezares

I see that in the hair length vs. heightthe plot has no correlation at all. I think the plot is strong because the data is spread out everywhere and you can't tell if it is positive or negative.Even if you take out the outliers it will not make a difference because the data is all over the place.In my opinion hair does not have nothing to do with height because people cut their hair all the time and can mess up the data. I think to be able to get the correct data is to get data from people that have never cut their hair. To compare it to there height.

In the plot of height vs. shoes size it has positive correlation and is very strong.I think the person that put the height of 160 cm and shoe size 9 cm kind had an error entering their data into the computer.I think the shoes size does cause height to change because as the size got longer the height got taller too.They both cause each other to change.I think the correlation does imply causality because if one goes up so does the other one.

-Mariana G.

What we can see from the scatter plot graph of hair vs. height is that there is zero correlation because it’s difficult to tell if the shown information is going on a positive way or a negative way. I know that its correlation is zero because the data is random all over the graph. The graphs correlation is strong because you can tell right away. The information that the graph gives me from the students in the class is the type of height and their hair length and how this two variables don’t have anything in common. There are some outliers that can be thrown away and it might give us a positive or negative correlation.

The relationship I see in this graph is that the shoe size and the height do have something in common. In this graph it shows a strong positive correlation. The person who is 160 cm. tall and has a foot that is 9cm. long is wrong or he/she made a mistake measuring his/her foot or didn’t type the right measurement of his/her shoe size. I think that the shoe size changes the height of some one. It’s casual because the larger the shoe size of a person is the taller the person gets/is.

-Cintia C.

I see in the graph that the points are everywhere and there is no pattern. This means that there is no correlation since there is no pattern. According to students from our class, height is no related to hair length. Although this graph seems to have no relationship all the points look centered but there are some outliers that look father or out of place points. Even if we erase the outliers from the data there would still be no correlation. Maybe some outside knowledge will be helpful to interpret the data. In the data of height vs. shoe size there is a relationship and a correlation. This correlation is positive. After picturing the line of best fit the correlation is strong. Regarding the person who is 160cm tall and has a 9cm long foot was an outlier. Probably the actual length of the foot was not measured correctly or s/he was not standing straight when the height was measured. I don’t think that shoe size causes height to change or height causes shoe size to change. Instead I think that people who are short often wear a smaller shoe size. This does not mean that one causes the other one, it might just reflect one another.

Judith D.

Looking at the hair length vs. height graph I noticed that the points were scattered in different places, and therefore I can assume no relationship between hair length and height. Indicating no correlation in this given data; neither weak nor strong. To conclude the height of a person can vary in sizes and this has nothing to do with their hair length because the hair length can also vary in sizes. Height is not a factor that affects hair length.

Unlike the above graph, the height and shoe size graph sort of implies a trend. There is a positive correlation indicating that the taller you are the most likely you have a bigger shoe size. With the exception of an outlier who states that a person 160 cm tall has a 9 cm shoe size. I believe this information is absolutely wrong because 9 cm is too short for a person to have in shoe size. From this graph we can see an obvious relationship with shoe size and height. No I do not think this casualty because it makes total sense that a taller person has a larger shoe size. I believe that our body is symmetrical therefore it makes sense that a taller person has a larger shoe size.

-Marilyn A. Rodriguez

Hair Length Vs. Height graph does not show a relationship between the Hair length and height, this leads to no correlation. This graph only gives the Hair Length and Height of each student and they show no relationship. The points on the graph seem unusual because they do not show any pattern or relationship between hair length and height. Other information that could be helpful to better interpret this data could be the times a year that a person gets a hair cut because height not necessarily has to do with hair length since a lot of the students get hair cuts every couple of months.

Height and Shoe Size graph shows a positive correlation, it shows a strong

relationship between this two factors. There is one exception that contradicts

the whole correlation and this is the person who is 160 cm tall and has a foot that

is 9cm long, this might have to do with the persons genetics or incorrect data.

Shoe size does not cause height to change, in my opinion is vise verse; height

causes shoe size to change. Correlation does NOT imply causality.

Laura M.

pWhat is seen in the scatter plot above (Hair Length vs. Height) is that there seems to be a very weak or no correlation at all between hair length and height. It is this because the scatter plot’s points seem to be completely random and therefore height and hair length seem to have a somewhat weak, or a negative, correlation. Although, if a few outliers were thrown out, the correlation would still be negative.

In the second scatter plot (Height vs. Shoe Size), it is seen that there is a positive correlation and it is strong. Even though there are a couple of outliers, one lied pretty bad to get 9cm long for their foot size. I believe height causes shoe size to change, although casualty may also be a factor. This study can not be used alone to prove height changes shoe size, or shoe size changes height.

Carlos S.

In the first graph you see data scattered all around. There is zero correlation between hair length and height.Since there is no correlation it isn't strong or weak. This to me shows no relationship could occur between the two and it is pretty much common sense. You can see a tall man with short hair and you can see a tall woman with long hair , hair has nothing to do with height and vice versa.

In the second graph you can now see a connection between the two variables. As you see height increase shoes size also increased, making this graph have a positive correlation which is strong. The person whom had the 9cm shoe size but was pretty tall most likely measured their foot in inches and accidentally didn't see the unit that was being used, which was centimeters. From looking at the data i wouldn't say shoe size causes height to change, but vice versa.

-Anibal G

According to the graph of Hair vs Height, there is little to no correlation on the graph. The results on this graph are completely random. Though it may seem there’s a very minimal correlation a person cannot make conclusion based on this because the other results are scattered. If you were to throw the few outliners from the data set the graph would remain negative. Probably the only information one could gain from this graph is that there is no relationship between hair and height because everyone is different and has a preference not according to their height.

Based on the data from this graph you can see a pretty strong correlation between height and shoe size. This correlation is positive and is strong because even if you remove some of the outliners the correlation remains positive and remains strong. There are many factors that could have affected the person who was 160cm tall and had a 9cm shoe size. One could be that the person accidentally used the wrong unit of measurement and perhaps measured in inches. 9 inches equals 22.86 centimeters which is very close to the measurement of another person who was 160cm tall. I believe that height causes shoe size to change not shoe size causing height to change because as our bodies grow, our body parts grow which includes our foot sizes.

Agustin V.

Post a Comment