Charts

In charts, data is represented graphically, so they are used in statistics mainly to get an overview of the collected data and to prepare information in an easily understandable way.

The most commonly used charts in statistics are bar charts, histograms, scatter plots, line plots, box plots and pie charts.

Bar charts

Bar charts are probably the most commonly used charts in statistics. Bar charts are usually used to show the frequency of different categories, but also to visualize numerical data, such as sales figures or population statistics.

In a bar chart, the length of each bar is proportional to the value it represents. The bars are usually arranged horizontally or vertically.

Histogram

A histogram is a graphical representation of the frequency distribution of a metric variable. To display a distribution of data in a histogram, the data must first be divided into classes, also called bins. These classes or bins are then represented by rectangles that lie directly next to each other.

This is also the main difference from bar charts: in a bar chart, the categories are already defined and do not have to be divided into bins as in a histogram. This becomes graphically clear because there is typically a space between the bars in a bar chart.

Accordingly, histograms are used for metric variables such as salary or age, and bar charts for ordinal or nominal variables such as gender or school grade.

Example Histogram

We would like to display the frequency distribution of the results of a statistics exam graphically. For this we have the respective scores of 150 students.

This is how it works with numiqo: Simply load the example data or copy your own data into the online statistics software, click on "Descriptive" and then "Charts," and finally select the variable "Score."

You will then get the following graph in numiqo, which provides a visualization of the results of the statistics exams of 150 students.

Scatterplot

Scatter plots are used in statistics to visualize relationships in data. In a scatterplot, two variables are plotted by representing each pair of values for a case as a point in a coordinate system. If, for example, 10 people are asked for their weight and height, the scatterplot shows 10 points.

With the help of the scatterplot you get a first indication of the association between the two visualized variables. If high values of one variable are associated with high values of the other variable, there is a positive association. If high values of one variable are associated with low values of the other variable, there is a negative association. If the points show no clear pattern, there may be little or no association between the variables.

Furthermore, there can also be a non-linear relation, in this case there is a pattern in the distribution of the points, but no straight line can be drawn through the points.

Line chart

A line chart is a graph consisting of a series of data points connected by a line. It is used, for example, to show a continuous change of data over time. In a line chart, time or the other continuous variable is plotted on the horizontal axis, while the values of the data to be illustrated are plotted on the vertical axis.

Line charts are particularly useful for visualizing trends and changes over time, and they are often used to represent economic and financial data, weather data, or scientific data.

Box Plots

Box plots are charts used to represent distributions of data. They provide a visual summary of the data by presenting important statistical measures such as median, quartiles, and outliers in a single graph.

Create charts

Charts are a valuable tool for visually presenting information. With numiqo you can create your own charts online and free of charge.

With numiqo you can easily create your charts online. To create a chart, simply copy your data into the table on the statistics calculator and select the variables for which you want to create a chart.

• Bar chart
• Box plot
• Histogram
• Scatter plot
• Creating Violin plot online
• Create raincloud plot
• Create Bland-Altman plot online
• Create Sankey diagram online
• and many more...

Which chart you should create depends on the information you want to convey and the scale level of your data.

In statistics, it is advisable to first examine the data using charts. This can indicate whether there may be differences between groups, for example. Hypothesis tests can then be used to assess whether the observed differences could reasonably be explained by random sampling variation under a stated null hypothesis.