Mind-mapping and outlining are two techniques for representing data or knowledge in tree form. A mindmap has a root node, or topic node, and other nodes expanding the topic in every direction. Although an outline typically does not have a root, it is essentially a tree (you can view it as a tree with a hidden root). A mind-mapper is a software that helps you create mindmaps, for example the free software Freemind. Similarly, an outliner is a software that helps you create outlines, for example Emacs/org-mode and Leo-editor. Both mindmaps and outlines are excellent tools for representing structured data and knowledge, especially during brainstorming and planning sessions. If you don’t want to be restricted to trees and want general graphs (including directed cyclic graphs), consider using concept mapping.
Which tool should you use? How to choose what is best for a certain task? In this post, I will try to answer those questions from my own experience.
Although mindmaps and outlines both represent tree-like data, there are some important differences between them.
First, you can easily notice a visual difference. A mindmap usually gives us a better overall view/understanding of the whole data. Using additional visual aids, like font styles, colors, size, border styles and images, it is easy to make important data stand out and add attributes to data items. Just a quick glance at a well-designed mindmap can give us a better overall idea than a careful and lengthy examination of the corresponding outline.
From the representation perspective, an outline uses a linear flow of the underlying data, while a mindmap uses a non-linear flow. Data in an outline is created, and then read and consumed, from top to bottom (of a page or a data file), jumping in and out of sub-trees (or sub-sections). An outline always imposes an inherent ordering of its data items, that is it is natural to say that an item is before another item. In contrast, a mindmap does not have that natural ordering. Instead, nodes expand their parents, eventually expand the root topic, in all directions, without imposing which comes first. Note that this does not mean a mindmap cannot have ordering, it is just not natural/obvious.
An outline can easily contain many details, even hundreds or thousands of small items (bullet points), while a mindmap typically contains a small to medium number of nodes. Of course, a mindmap can have thousands of nodes, but then it will look like a dense spider net and will make the reader lost in the sea of information. So, an outline can give high-to-low levels of details, while a mindmap usually represents a high-level abstraction. In other words, the spectrum of details of outlines is usually much larger than that of mindmaps.
From the operation point of view, it is often easier to add or remove a node and to re-arrange nodes in a mindmap than in an outline.
Because of the superior visual capability of mindmaps compared to outlines, mindmappers usually focus on providing good graphical user interface, while outliners often add many useful extra features besides constructing outlines. For example, org-mode can represent (scheduled and unscheduled) tasks, making it a very powerful task management and agenda software. Org-mode can help you write documents and export, or publish, them to web pages, PDF’s, and other formats. Documents may contain code snippets, and the code can even be executed automatically and their results are embedded in the output documents. Leo-editor makes an excellent project management tool, where all code files can be managed and generated from a single outline. Code segments can be taken out into a separate tree view, as cloned nodes, so that programmers can focus on only related parts and are not distracted by the other parts. It is not the fault of mind-mapping that mindmaps often lack these features. In theory, mind-mapping software can implement some of these features. But they rarely do.
Knowing the differences between mindmaps and outlines, it is now easier to choose an appropriate tool for a certain task. In general:
- If your data must have a certain ordering (that ordering is important) or a linear flow, use outlines.
- If you need to represent very fine level of details, with large number of small points, use outlines.
- If you need any of the features that only outliners currently provide, use them.
- Otherwise, use mindmaps, especially when you need its flexibility in representing nonlinear data, or when you want to represent a good overview of the data (e.g using colors, fonts, etc).
Sound too generic? Let’s study some specific cases to get a better idea.
Case study 1: taking notes
Note taking is very important in study, meeting, brainstorming… However, notes in different context may have different characteristics. In a brainstorming or planning session, or in a meeting, the notes are usually nonlinear. Taking notes in such contexts often requires quickly adding and moving nodes, as well as switching between different sections. Also, a good overview of the all the ideas is crucial. Finally, there is usually not much detail in the notes (an idea is often just one short sentence). Therefore, a mindmap is more appropriate for this type of notes.
However, notes taken in a lecture, as in a college classroom, are different. They always have a linear ordering, and this ordering may be important to the understanding of the lecture. Moreover, the need to quickly move between sections or add/remove details is usually low. Finally, there usually are a lot of fine details. Thus, an outline may be more suitable for lecture notes.
Case study 2: creating documents and code
Let’s say you have to produce a (scientific/technical) document or a software, or (usually) both, from scratch. A typical simple process would be:
- First, you brainstorm to gather all ideas.
- You analyze the advantages and disadvantages of the ideas, eventually decide which to use.
- Having the final ideas and an overall understanding, you plan the structure of the document and/or code.
- You write the document and/or code, better at the same time rather than separately, following the planned structure.
- Later, you may want to come back to review ideas in step 1 and 2.
It is straightforward to see that mindmaps are suitable for steps 1 and 2, while outlines (in a tool like org-mode or Leo-editor) are more suitable for steps 3 and 4. In step 2, the ideas that you decide on can be marked using colors or other visual aids. Usually, the mindmap in step 2 can be exported to an outline (or an outline tool can import the mindmap). Having the original brainstorming mindmap is often useful for later reference.
Which tool (mindmap or outline) do you think is more suitable for planning this post?