# Questions tagged [boxplot]

A graphical display to summarize the distribution of a sample. It displays five numbers plus (possibly) some outliers - those five points being the median, hinges (approximate quartiles), and the largest and smallest value not counting any points marked as outliers.

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23 views

### Is this the appropriate way to conduct an ANOVA on this data?

I have collected data on 216 individuals. I measured the concentration of the same 7 Substances in each individual, represented by Sub1:Sub7. The concentration of these Substances may be different in ...
59 views

### Interpreting a boxplot with outliers [closed]

I have this specific boxplot that I would like to interpret in my conclusion for my master thesis. I noticed that the most right box does not have any outliers, but a very broad Q2 and Q3 range. Also ...
22 views

### Interpretation of boxplot overlaps

Let's assume that I have the boxplot below that shows fraction of hits for a query. I'm trying to understand if there are any meaningful differences for each type (x,y) and for each category (A-D). ...
23 views

### Comparing boxplots with different sample size

Let's suppose somebody did an experimented to measure how high a plant can grow on different soils. The experiment has been repeated different times for the different soils, with some soils having e.g....
33 views

### Why do box-and-whisker plots use interquartile range, when it deliberately ignores everything below the 25% percentile and above the 75% percentile?

Why ought IQRs, and anything that relies on them like boxplots, be used when they ignore data? I replicated Wikipedia's graphs.
615 views

### Missing quartile in boxplot

Currently I am creating a box plot. I am new on the field of statistics and especially box plots. Find the picture following: On the y-axis find the number of messages. I have problems understanding ...
16 views

### Plotting series of numbers while protecting privacy

I have 2 series of numbers e.g x=[1,3,4,6,9] y=[100,179,210,400,650]. I want to plot them and show that plot in a manuscript. However, these numbers represent some private information and hence I don'...
15 views

### Correlation with Pearson possible for Continous - Dummy Variable? Otherwise options?

I assume that I cannot interpret correlation coefficients given by Pearson method for continous - dummy variables. Is this correct? Which options can I pursue otherwise? Its for the decriptive ...
26 views

### How to define a threshold based on box-plot

I have a set of ordered number list as follows. 25789, 20500, 18888, 15000, 13200, ...., 118, 8, 1, 0 In my dataset most of the values are in the range of (1000-...
84 views

### Should I compare the median or mean for my data?

I have a data frame in R that contains the information about 252 freshman university students. ...
23 views

### How to deal with the categorical variables with few data for prediction

The image below shows how the rating for the heating quality will affect sale price.The data is about apartments and it's properties. E.g Rooms, GarageSize, BasementSize, etc. This visualization will ...
226 views

### boxplot in R shows wrong outliers

Can someone explain why does boxplot in R show me outliers when they are actually not? I have a dataset for computer sales and I have to predict the price based ...
28 views

### I have two groups of data with (the same) two variables each, how can I plot these groups against eachother?

Please bare with me, I am very new to statistics. I have two data groups (Location A and Location B), at both locations I recorded two variables (Noise and Activity), I am trying to find out how I ...
47 views

### Displaying high dimensional box plots

If several box plots are to be displayed on a graphic where the X-axis represents a unique level, but one which is continuous (like per-year over a very long study) is there a well known way to ...
703 views

### Ways of visually comparing variance of data [closed]

I have a dataset containing 8 categories, I now want to visually compare the variance between the categories. The most common approach would be to use box plots or violin plots but I would like to ...
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### Is it possible to experimentally reproduce the probability of type 1 errors in significance tests?

In some fields, a lot of sample studies feature statistical tests. Oftentimes, box plots of sample distributions are shown. I was wondering whether i could read distributional parameters from these ...
239 views

### Biostats two way anova in R boxplot visualisation

I am having a problem analyzing some data from a recent experiment in R. The experiment was balanced with 5 replicates in each group. It included two factors (plant type and leaf age) with 15 ...
132 views

### Interpreting percentage of an outlier in a box plot

I have a dataset of 21 points. Below is a box plot of that data. I am trying to interpret this boxplot. Is it safe to say that 96% of my data points fall under 48? I derived 96% by dividing 100 with ...
134 views

### Is it reasonable to display “percentage data” in a boxplot, why?

I have data that are in fact percentages of C (bound to clay) combusted in a certain temperature interval. Exemplary data: ...
482 views

### How to check the assumptions of ANOVA from a boxplot?

This boxplot shows 5 different forms of dancing. On the y-axis we have the number of injuries. This is an ANOVA model. The question is, what assumptions could not be met according to this boxplot? I ...
203 views

### How can this boxplot be transformed suitably?

In R, I have produced a boxplot for two different groups, with discrete y-values between 1 and 20. My goal from this work is to investigate whether the average count differs between A and B: ...
422 views

### Boxplot only display points

I have a rather mysterious problem when I try to do a simple boxplot with boxplot(data$sex,data$freq) but I'm unable to display box plot, and I cannot figure out ...
872 views

### What's the history of box plots, and how did the “box and whiskers” design evolve?

Many sources date the classic "box plot" design to John Tukey and his "schematic plot" of 1970. The design seems to have stayed relatively static since then, with Edward Tufte's cut-down version of ...
65 views

### Create a probability distribution using boxplot information

How do you fit/estimate a probability distribution using only the information from boxplot, i.e, max, min, 1st quartile, 3rd quartile and median? I don't have access to raw data but only a boxplot ...
52 views

### box plot analysis.

I have been asked to comment on what I observe and I am unsure of what to say about not having 1 quartile for race 1, not having a lower whisker for race 2, and not having 1 quartile for race 3. I ...
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### Can you let me know how you would analyze/compare this 2 box plots?

I am unsure of what these 2 box plots are telling me about the distribution of the data and how the are different. Any information will be appreciated.
1k views

### Qualitative difference between boxplots and error bars (descriptive vs inferrential statistics?)

Assume I have test scores from several groups, with all samples of equal size. Assume I want to plot this data so as to emphasise in the simplest way (without showing the distributions) the difference ...
38 views

### What information can be gained from the the density or the distribution of outliers in box plots?

Hi everyone, I am using box plots to show my results for the simulated energy consumptions. However, the distributions of the outliers for the months May and June are weird to me. Specially ...
2k views

### Outlier detection for skewed data

I have a dataset as below: 4.8856 4.8914 4.9125 4.9338 4.9563 4.993 4.9947 4.9947 4.995 5.2932 4.981 4.981 4.981 4.982 4.982 4.982 4.982 4.983 4.983 4.984 4.984 ...
70 views

### What are considered as outliers

I am using this function to see, if I have outliers. ...
29 views

### Simplify the data in a boxplot

I'm a web developer and currently working on visualizing the execution time of processing a request. Thus, I can create a list with all execution times (e.g., ...
235 views

### SPSS P-value for box plots?

I got some groups to compare. My variabels are in the physical fitness area so BMI, bodyfat etc... I have 4 groups, categorized in gender and two school classes from 2010 and 2012 (Men2010 Men2011, ...
76 views

### ideas for presenting data from multiple conditions

I have some data from an experiment that has 7 variables that have two levels to generate the conditions for the experiment. Consequently there are 128 (2^7) different combinations of variables. I've ...
140 views

### Help needed with my box plot

I decided to give box and whiskers plots a try with my data. However, the produced box plots look a bit abnormal. I have not been able to find such cases online. For example, my "T" value has no box ...
2k views

### How to deal when you have too many outliers?

I have attached the boxplot of a variable called Fare(of a journey). This is a continuous variable which has outliers. According to some articles on outliers, I learned that any data point that is ...
197 views

### ANOVA ASSUMPTIONS, LOW or NONE VARIANCE IN PART OF DATA

It was said to me there is a problem here, cause there is no variance of the control and ulex treatment - it can be the nature of the data or it can be the assumptions to apply anova in these data ...
1k views

### Why doesn't the fact that 1 median is lower than another median, mean that most in group 1 are less than most in group 2?

I believed that the boxplots below could be interpreted as "most men are faster than most women" (in this dataset), primarily because the median men's time was lower than the median women's time. But ...
7k views

### ANOVA - Homogeneous variance, what to look for in a boxplot

I'm just starting out learning about ANOVA, I'm having trouble understanding how to check for homogeneous variance assumptions. One source I have seems to be looking at box-plots, and another looks at ...
2k views

### Understanding and Interpreting letter value boxplots

I have read through the R documentation of lvplots, but it didn't provide enough material on how I would interpret these plots. I want to just have an intuitive ...
347 views

### Outliers in boxplots

I have a set of area measurements for objects in different groups (e.g., cities), and I want to provide a visual summary of them. While Quartiles and medians are quite interpretable, I'm trying to use ...
68 views

### How can I compare two variables when one has lots of zeros?

Specifically, I want to understand the contributions to insurance premiums and claims. In this case, everyone pays a premium, but only some people make claims. I want to understand whether the ...
214 views

### Relationship between the length of the whiskers and the tails of a population in boxplot

Why in the boxplots long whiskers are associated with a heavy tailed distribution and short whiskers are associated with light tailed distributions populations?
2k views

### How are whiskers in a Boxplot of different lengths? [duplicate]

The formula for calculating the position of the whiskers is Q3+1.5IQR and Q1-1.5IQR But doesn't that mean that the length of the whiskers should be of the same length? How are they of different ...
2k views

### What exactly does a Boxplot show? [duplicate]

Having a Boxplot like the following, how do I read it?
139 views

### Exploratory data analysis techniques to percentage variable

I'm running an analysis about a dataset with three variables: Income, number of residents per residence and percentage of income spent on rent (response variable). What descriptive statistics should I ...
2k views

### Why do means appear outside the boxplot?

I have plotted the boxplots of the distributions of certain groups and I was bewildered to see that the means appear outside the boxplots. How could this be explained? Since boxplots are a ...
972 views

### box plot in R: Do the outliers count when the quantiles are being determined?

I have a 1 dimensional dataset and I use the boxplot function to make a box plot. Then I can see that I have some outliers. Do the outliers count when the ...
346 views

### Boxplot for 2 distributions with different number of data in each

I had 2 different sets of data which I wanted to compare using a boxplot. However the number of samples / entries I have for each of the 2 types differ. Should I just create a boxplot for both of ...
The standard definition of an outlier for a Box and Whisker plot is points outside of the range $\left\{Q1-1.5IQR,Q3+1.5IQR\right\}$, where $IQR= Q3-Q1$ and $Q1$ is the first quartile and $Q3$ is the ...