How do you use histograms and scatter diagrams to analyze project data and trends?

1 What are histograms?

A histogram is a type of bar chart that shows the frequency of data values in different intervals or bins. It can help you understand the shape, spread, and central tendency of your data, and compare different data sets or groups. For example, you can use a histogram to see how many tasks were completed on time, ahead of schedule, or behind schedule in your project, and how they vary across different phases or teams.

2 How to create a histogram?

To create a histogram, you need to collect and organize your data into bins or categories. You can use a spreadsheet software like Excel or Google Sheets, or a statistical software like R or SPSS, to achieve this. First, decide on the variable or attribute you want to analyze, such as task duration, defect rate, or customer satisfaction. Then, sort your data in ascending order and find the minimum and maximum values. After that, choose the number and size of bins or intervals for your data. You can use a formula like (maximum - minimum) / number of bins, or use a built-in function in your software to do this automatically. Next, count how many data values fall into each bin or interval and record the frequency for each bin. Finally, draw a bar chart with the bins or intervals on the x-axis and the frequency on the y-axis; ensure that the bars are touching each other and have equal width.

3 What are scatter diagrams?

A scatter diagram is a type of plot that shows the relationship between two variables or attributes. It can help you see if there is a correlation, or a linear or nonlinear association, between your variables, and how strong or weak it is. For example, you can use a scatter diagram to see if there is a relationship between the number of defects and the number of changes in your project, or between the customer satisfaction and the project cost.

4 How to create a scatter diagram?

Creating a scatter diagram requires collecting and plotting data as pairs of x and y values. You can use spreadsheet or statistical software, such as Excel, Google Sheets, R, or SPSS to do this. First, decide on the two variables you want to analyze, such as defect rate and change rate, or customer satisfaction and project cost. Then, enter your data as pairs of x and y values in a table or matrix. After that, draw a plot with the x variable on the horizontal axis and the y variable on the vertical axis. Lastly, plot each pair of x and y values as a point on the plot. You can use different colors, shapes, or symbols to represent different data sets or groups.

5 How to interpret histograms and scatter diagrams?

Histograms and scatter diagrams can help you answer questions like what is the most common or typical value of your data, how spread out or concentrated it is, and whether there are any outliers or anomalies. You can also determine if there is a pattern or trend, a positive or negative correlation between variables, and a linear or nonlinear relationship between them. To interpret histograms, you can look at the shape, center, and spread of the bars to identify symmetric, skewed, bimodal, or uniform data; as well as gaps, peaks, or tails in the bars. With scatter diagrams, you can examine the direction, form, and strength of points to determine a positive or negative correlation; a linear or nonlinear relationship; clusters, outliers, or gaps; and compare them across different data sets or groups.

6 How to use histograms and scatter diagrams for project improvement?

Histograms and scatter diagrams can help you improve your project quality and performance by identifying root causes of problems, evaluating changes, monitoring progress, and communicating project data. To use these tools for project improvement, you need to define objectives and metrics, collect and analyze data, identify gaps or trends, implement corrective actions, and report your findings. Doing so will enable you to measure the impact of any changes you make to your project.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?