Tables are a very important part of scientific papers. A good table should present the data simply, clearly and neatly, and allow the reader to understand the results without having to look at other sections of the paper. A bad table can be very confusing, and may reduce the chances of your paper being accepted.
In this post, we will look at the basic rules for creating effective scientific tables.
Let’s begin with an example of a bad table, highlighting some common errors and showing how the table can be improved.
Can you see anything wrong with this table?
Fig. 1: Example of a poorly formatted table that can be improved
Let’s start with the table formatting and editing.
Rule 1. Use a separate cell for each value
In the top row of Fig. 2 (below), the author has placed two columns of data in the same cell. We often see tables with only one row and column, with the rows of data arranged using the space bar or "tab" button.
If the table is adjusted or moved (for example, if the table size or text size is changed) the table layout will change, causing the data to be misplaced (as shown in the bottom of Fig. 2).
Fig. 2: Tables created without cells can become disorganised if resized or moved
Additionally, if there are empty cells, rows or columns, it can be difficult to know if data is missing from the table, and impossible to know which columns or rows the data should be in.
Therefore, tables should be created with the correct number of rows and columns - use one cell for each piece of data.
You can add new rows and columns to an existing table by right clicking on the table, selecting “Insert” and choosing to insert new rows and columns above or below the existing rows or columns.
It is also possible to insert multiple rows/columns to a table at the same time. For example, if you would like to add three columns to the left of your table, highlight the first three columns, right click and choose “Insert Columns to the Left”.
Rule 2. Use only horizontal line borders and double line spacing
Most journals ask that tables only contain only horizontal lines as borders. Additionally, most journals require the text in tables to be double-spaced. It is always a good idea to look at the “Instructions to Authors” for your journal, and check if there are any special instructions for tables.
In Microsoft Word (version 2007 onwards), you can change the table borders by clicking on the table and using the menu that appears in the “Design” section under “Table Tools” - as indicated by the red arrows in Fig. 3.
Alternatively, right click your mouse over the table, and click “Borders and Shading” to change the table borders.
Fig. 3: How to format table borders in Microsoft Word
Rule 3. Use clear and informative titles
Generally, you should include information on the test system (e.g. the species, cell line or type of patients), as well as the type of treatment (e.g. salinity or the drug name) and what was measured (e.g. plant height, blood pressure or cell proliferation).
So the title for the Table 1 could be:
Table 1. Height of wheat plants after salinity treatment
Table 1. Effect of salinity on the growth of wheat plants
Sometimes, it can also be a good idea to describe the main result in the table title. This will help the reader quickly understand your data. For example:
Table 1. Salinity reduces the growth of wheat plants
Table 1. Exposure to salinity reduces the growth of wheat plants
It’s not always possible or necessary to include the result in the table title, for example tables that show a list of data (such as patient characteristics, plant cultivars or PCR primers) or tables that contain complex or conflicting data.
Let’s see how the table changes if we apply these rules to the Table 1. I’ll insert a new column to the left of the table and place each value in a separate cell (rule 1), only use vertical rules and double space the table (rule 2) and use an informative title (rule 3).
Fig. 4: Improved table after placing values in individual cells, formatting and double spacing, and adding an informative title
I remember trying to write my first manuscript. Why was it so difficult? Why did I feel like a failure?
Now I’m a scientific editor, I know every single scientist struggles (or at least used to struggle) with writing manuscripts.
That’s why I’ve created a simple, FREE checklist to help you write better manuscripts.