# 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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25 views

### Identical interquartile ranges for distributions with different means and numbers of data points

Consider these two distributions, representing ratings (in the range 0-9) given in an experiment for two different conditions A and B: ...
53 views

I'm trying to find out if there's a significant difference between relative abundance (response variable: rel.abund) and habitat (predictor variable with levels lagoon, bank, shelf: Habitat). This is ...
13 views

### should I check and remove outlier from dataset through multi round

I have a data set as: x1, x2, x3... x9 (non-normal distribution). I check it with box-plot and find one outlier as x9. Normally I will stop then remove x9 and use the new data set. But when I check ...
15 views

### Implementing classification with rejection and interpreting 2D ambiguous data

Let's say we're going to train a classifier with the full data set. There's also a reject logic for ambiguous regions in the data. So, at the end, the final system outputs reject or 0 or 1. That is, ...
1 vote
141 views

### Interpreting box plots with categorical variables

How do you explain a box plot with categorical variables on the x-axis? For example, I have these two box plots, how do you interpret relative comparison of each category within the box plot? Sample ...
16 views

### How to find all the data on a box-and-whisker plot? Most importantly the mean

I am super stuck on the question. I looked up on how to find the mean on a Box-and-whisker plot, and never got a clear answer.
20 views

### Residual Analysis in R

I am trying to develop a strategy to deal with outliers. Below is the residual boxplot that I have generated for the test data, train data and both the test and train data. My question is, what is the ...
66 views

### Boxplot or Scatterplot?

I created boxplots for 5 traits to show the spread of true age for each variant of each trait in both samples between 2 observers: A professor suggested that I should use scatterplot of Price vs Kim ...
120 views

### R Tukey Anova: Can non-overlapping boxplots share the same letter of significance in Anova / Tukey Test?

I conducted a one way anova followed by a tukey-test in Rstudio and used a compact letter display to add letters of significance to a ggplot. After a positive Grubbs-outlier-test I removed an outlier ...
1 vote
30 views

### Grouped Boxplots in R [closed]

I want to draw the same exact graph in R. However, I want to consider two options: (1) with one x axis for each of the genders & (2) two different xaxes for each of the gender. Here is also the ...
14 views

### Testing hypothesis that mean of grouped quantitative data is increasing in one direction

My predictor variable is quantitative, but falls into nine discrete groups (i.e., values are either 60, 125, 200 etc.). I have a responder variable that is quantitative and continuous. I have made a ...
288 views

### Are there any simpler alternatives to boxplots and barplots that can faithfully represent data with outliers and strongly varying ns?

I have a dataset of passwords that looks like this: My goal is to make a graph that accurately showcases the strength of each category so my initial plan was to group the data by category and ...
198 views

### Boxplot | 5-Number-Summary

I have a question regarding the boxplot. On some web pages, the Minimum and the Maximum of the 5-Number-Summary correspond to the whiskers. However, regarding this definition, my question is: how is ...
127 views

### Boxplots: valid method for visualizing collinearity?

I recently heard one can detect collinearity between a factor (Species) and a continuous covariate (TL) simply by making a boxplot. If the plots don't overlap, there is evidence of collinearity. I'm ...
1 vote
64 views

### T-test and linear regression are significant but a grouped boxplot shows similar medians

I did a mean differences test, the t-test gave me a p-value of 0.034 and a regression test gave me significant differences as well. But when I plot my data with a boxplot, I see that the medians are ...
2k views

### Why use bar chart with error whiskers instead of box plot?

Bar charts with error whiskers, like the one below (taken from What type of plot is it?), seem to be quite common in some communities. I wonder, however, why is a bar chart used, and not a box plot? ...
489 views

### What type of plot is it?

Here is the plot ,which I do not know what type of plot it is. It is so similar to box plot, but it does not have first quartile. How we can find mean and standard deviation using this plot? UPDATE: ...
1 vote
225 views

### Boxplot whisker don't match the calculated values [closed]

Here are my data points: ...
42 views

### Boxplots t tests and Bonferroni correction

I'm comparing three groups: people that have had two infections, people that have had one infection and people that have had zero infections. I'm showing them on a boxplot (regarding age for example) ...
677 views

### Is a boxplot useful, when it doesn't even look like a box?

I want to visualize some data with a boxplot -- and I am wondering, if the boxplot is even the correct way for visualizing the data. I want to compare three datasets (40 entries each) using boxplots. ...
1 vote
439 views

### Visualize distribution (box plots like) with many and extreme outliers?

I have values with extreme outliers and want to visualize that. But the box plot doesn't seem a good choice for my data as you can see here. Most of the values are less than 50,000. But some them are ...
4k views

### How should we do boxplots with small samples?

This question is inspired by this posting, plus a comment by @StephanKolassa and an answer by @dipetkov who point out that the boxplots presented in that question are misleading. As is pointed out, ...
1 vote
245 views

### How to use box plots to detect outliers?

Suppose for simplicity that we have Gaussian distributed data with some outliers, whose typical characteristic is getting values that are far from the mean. Suppose my sample size is ...
1 vote
139 views

### What is the best plot I can do to understand true values vs errors in prediction in a regression problem?

I am facing a regression problem and I would like to understand how my errors distrubuite along the true values I have. For the moment, I have done this scatterplot: but I want a plot that directly ...
3k views

### Visualize a continuous variable against a binary variable

I want to visualize a continuous variable, BMI index, against a binary variable, heart disease. I want to check by visualization ...
1 vote
226 views

### May the cumulative distribution function be used to calculate the inter-quartile range and vise-versa?

May the cumulative distribution function be used to estimate the inter-quartile range? I am drawing their similarities. The IQR is found via a boxplot which has percentiles. A percentile comes from ... 40 views

### IQR range in boxplot

I'm having a look at altair docs, and I don't understand why, in the last two groups (85 and 90), that have a very low IQR, they have similar whiskers than in the first group, where the IQR of the ...
1 vote
148 views

### How to use side-by-side boxplots to assess assumptions of a 2 sample test?

Here is the context: So we can analyse this using a 2 sample t tests. The assumptions of t-test comparing the means of two independent samples are populations being compared should follow normal ...
50 views

### Interpreting boxplot VS stacked histogram in example

I understand what a boxplot and histogram are supposed to show, but I'm a bit confused on how it is being presented in this graphic printout from R. The picture is taken from Beyond Multiple Linear ...
785 views

### Box Plot Upper Fence is greater than Max

Hi is it normal for the upper fence to be greater than max? If not, what might have gone wrong? I am using Empirical Rule and doing calculation mean +3 * IQR Thanks
436 views

### How can I test whether one empirical CDF is to the left or right of another?

I am currently working with a box plot (shown below) that consists of two boxes per value of one of the independent variables (call it $x$). The other independent variable is indicated by the two ...
499 views

### SIgnificant P-Value with overlapping boxplots

I'm confused about some of the results I got after plotting my data. I have a data set that includes tests scores and a binary group assignment of either polypharmacy or non-polypharmacy. the scores ...
227 views

### How do I determine if differences between medians are statistically significant when notches are very close (see "C" and "D")?

Regarding "C" and "D": Is there a way other than visually inspecting the notches from the boxplots? I know the range of values for "D" is lower than "C" and the ...
39 views

### Graphic representation of averages

I have a series of averages. One of these however turns out to take too high a value due to a N. low equal to 1. Let me explain better by means of an example: I have to calculate the averages of the ...
68 views

### Representing MAE and standard deviation for multiple models over multiple bins in python?

I have 21 regression models. I am plotting MAE and Standard deviation of models using a errorbar plot in python. However, if I bin the data (say 10 bins), and for each bin now I can calculate MAE, ...
1 vote
2k views

### mean + 95 % confidence interval versus boxplots

I am wondering about the use of boxplots versus mean with 95% in a figure? A boxplot will give you median and you can add a notch to show the 95 % CI for the median so it is quick and easy to compare ...
1 vote
1k views

### How can I see Kurtosis in a box plot?

How do I know whether a distribution is leptokurtic or platykurtic by only having the box plot?
1 vote
5k views

### How to use a boxplot with grouping and multiple variables

I am trying to create a graph in R that has 7 variables on the x axis, and size on the y axis. Each variable has 2 treatments and sex (drug 1/2 & M/F). I am struggling to understand how to: ...
395 views

### Detecting and dealing with outliers in a sales prediction dataset of "Rossmann"

I have been working on a dataset for which the task is to forecast the sales of the drug sold by 1115 drug stores of the Rossmann chain. The dataset is fairly large with over 1m records and as many as ...
1 vote
189 views

### Proper way to compute stats of multiple box plots

If I have 10 sample distributions that I've calculated the box plots for, what is the proper way to summarize that into a single box plot? I should add that the sample distributions are not drawn from ...
53 views

### I want help to explain boxplot

I want help to explain this boxplot I generated data from this code set.seed(1234); a4 = matrix(rnorm(10*200, 1,1), 200); boxplot(a4) I only see 10 samples ...
646 views

### What does it mean when 25th percentile, median and 75th percentile are the exact same value?

I am trying to study the distribution of a variable, tax rate. When I calculate some stats and make some plots, I notice that the 25th, median, and 75th percentile are the exact same value. ...
1 vote
141 views

### Power transformation & pearson's correlation - how to interpret?

In the first phase of my analysis, I had transformed a skewed variable (normality violated, heterogeneity of variance violated) using a power transform (x^-2) to be able to conduct parametric tests. ...
368 views

### What exactly does standard deviation mean in this dataset, and how do I go about generating it in another?

I'm trying to add error bars to a boxplot in R. I need sd/se and all of the instructions I can find that I can understand have datasets with sd/se already calculated, like so: My dataset is set up ...
81 views

### Box and Whisker plot - dots over the box

I have a box and whisker plot, and I am unable to understand the meaning of the dots over the box. In the following example, I understand that outliers are the data points which do not "fit" ...
1 vote
143 views

### Creating box plots from a count (or frequency) table

I have a census data where the number of population at each age is indicated and I am trying to create a box plot for the age of the entire population. At first I tried to repeat the 'age' by the ...
229 views

### How to name and treat such a distribution of extreme values / outliers?

In this sample data I have 4600 teenagers with their telephone calling frequency per week. Most of them are "normal" (max 5) but some are extreme with up to 75 calls per week. I learned to ...
146 views

### What does the "mass" of a box plot mean?

By “mass” I mean the size of the two subretangles that make up the box in a standard box plot. I thought the mass quantified the observations below and above the median but if it did so every box plot ...
1 vote