The histogram looks very similar to bar graphs, but there is one outstanding feature that differentiates them. In bar graphs, the bars are separated by continuous intervals, but the bars of the histogram are not separated and always touching. Further features of histograms are that the x-axis is measured in ranges to define various parts of the data.
When to Use Histogram
Histograms are an excellent way of describing numerical x-value data. For example, graphing the height of several merchants on the x-axis versus weight on the y-axis would use a histogram, because the x-values have arithmetic values. Still, colors graphing on the x-axis contrasted with their acceptance on the y-axis would not use a histogram because colors do not have arithmetic values but instead, they are categorical. Usually, bar graphs are used when relating uncompromising data, and histograms are used when linking arithmetical data. At times when not sure of what to do with a big set of measurements shown in a table, you can use a Histogram to arrange and display the data in a more user friendly and understandable format. It makes it easy to see where most of the values fall in a measurement scale, and how much difference there is. It is also helpful to create a Histogram when you want to perform the following activities
To summarize large data sets graphically
- With histogram, you can make it much easier to understand by summarizing it on a tally sheet and organizing it into a Histogram.
To compare process results with specification limits
- When you add the process specification limits to your Histogram, you can know rapidly if the current procedure was able to produce “good” products.
- The Specification limits may take the look of weight, length, density, quantity of materials to be delivered, or whatever is crucial for the product of a given process.
To communicate information graphically
- With histogram, team members can with ease see the values which occur most times, (I.e. the frequency of values). If you use a Histogram to summarize big data sets, or to relate measurements to specification limits, you are using a powerful tool for communicating information.
To use a tool to assist in decision making
- In the use or creation of histogram, all sizes, certain shapes and the spread of data have meanings that can assist you in inspecting issues and making decisions.
- But always remember that if the data you have in hand aren’t current, or you do not know how the data were collected, it’s a waste of time trying to chart them. Performing measurements cannot be used for making decisions or estimates when they were made by a process that is different from the present one or were collected under conditions that are not known.
Benefits of the Histogram
The advantages of the histogram are in its applications.
- Using the histogram helps us to make the decision making process a lot more easy to handle by viewing the data that was collected or will be collected to measure pass performance of any given company.
- A histogram offers a way to display the frequency of occurrences of data along an interval.
- When you Use the data presented in the histogram, you can regulate statistical information.
- The Histograms track helps determine trend. For instance, if you have divided the horizontal line into 12 segments representing January through December and the vertical line is divided into temperatures, you can see the trend of temperatures during the year.
- You can use histogram calculations to make your picture clearer to read and to categorize your data into many diverse classes.
In conclusion, when one uses histogram for calculations of frequency and other necessary actions like decision making and so on, it is the area of the bar that shows the frequency of incidences for each bin. Therefore, this shows that the height of the bar does not really show how many incidences of scores there were within each specific bin. The histogram is the produce of height multiplied by the width of the bin that shows the frequency of incidences within that bin.