How to Make a Data Table

If you need to collect large amounts of information, organize it efficiently by putting it into a data table. Like spreadsheets, data tables consist of rows and columns. Each column represents a data field, and the cells (part of a row) below a column hold values for that field. Although data tables are particularly useful for storing data gathered from scientific observations, you can use a data table to help you organize any type of information. The type of data table you create will vary depending on the type of data you collect.

Male hands typing on a computer keyboard
Typing on a laptop.
credit: serggn/iStock/Getty Images

Anatomy of a Data Table

The term “data table” can mean many things. Some programming languages, such as C#, allow you to generate data tables based on existing data. Relational databases also contain data tables that have keys, constraints and other properties. For websites, HTML tables are used for design purposes and, of course, to organize data. Aside from software or website, you can also create a data table by drawing a grid on paper and filling the grid with data values. These types of tables are much simpler than database data tables -- all you need to do is to define column headers and add your data. You can make your data tables more readable and efficient by following a few design principles that experts use on and off the Web.

Define Your Data Entities

If you want to build a database, you'll do it more efficiently if you first analyze your problem and record the data that you wish to store in your tables.Similarly, to design a simple data table, think about the information you wish to capture and write it down. For instance, if you want to create a data table that holds CD information, you might write down the things you'd like to know about a CD. Those might include artist, track title, track length and genre. The entities that you come up with become your data table's columns. Because this example data table about CD information stores only information about one entity -- CDs -- the data table will be a one-dimensional table.

Arrange Your Columns Efficiently

Although you can add data columns to a data table in any order, it is more efficient if you put the most important entities first. The Windows File Explorer is a classic example of a data table that illustrates this principle. Many people probably have the "Name" column as the first column because file name is usually the most important entity. On the other hand, you may have a data table in which no entity is more important than another. Imagine a data table that stores the names of files you download each month. In this type of scenario, you'll find information more efficiently if you arrange your columns by month name. Other times, you may want to place the columns in alphabetical order to make it easier to analyze your information. Always look for opportunities to combine several columns into one. For instance, if your data table doesn't need a First Name and a Last Name column, simplify the table by creating a single column called Name.

Create Advanced Data Tables

The CD data table is one-dimensional because it tracks only CD information. Suppose you want to record monthly rainfall and high temperature in Detroit. In this example, you have one entity, Detroit weather stats, and another entity, months of the year. You can track this information in a two-dimensional data table. You could put "Rainfall" in column 2 and "High Temperature" in column 3 of your data table's first row. Move to row 3, column 1 and type "January." Type "February" in row 4 below it and continue until the first column contains the names of the months. When you’re done, you have a two-dimensional data table that looks like a spreadsheet. The second row, which is empty, helps separate the column headers from the data. You can then store rainfall and high temperature values for any month by typing it in the appropriate table cell.

Grouping Tips

Some columns in a data table may contain repetitive data. For instance, if you store sales by department, your data table may contain two columns: Department Name and Sales. In this scenario, you may have only three department names and many sales per department. If you separate the department names into groups, you’ll find it easier to analyze your data later. For instance, the first 10 rows in the first column might contain the word “Camera Department.” The corresponding values in the first 10 rows of the second column would contain sales for each department. When you design a data table this way, you emulate the way Excel can sort and group columns. Add an empty row between groups to make it even easier for people to visualize your information.