Does visual mapping help revision?

Visual maps, whether in form of mind maps or the more complex concept maps, are a mainstay of revision advice given to pupils in secondary schools. People use such mapping techniques for many other purposes; for example to organise or brainstorm ideas. However, in schools they are frequently taught to pupils as a way of processing and remembering information – and most revision guides suggest creating visual maps of one form or another.

The idea that mind mapping helps revision is wide-spread and unquestioned. For example BBC bitesize have a mind mapping tool that students can use to help revision. Books exist which promise ‘A’ grades in GCSE through the use of mind maps. It is a common claim that using mind maps will improve pupils’ memory for the information encoded using the technique:

“Mind Maps are widely recognised as an effective method to improve understanding and memory through the visual representation of information.”

It’s difficult to pin down exactly why visual mapping is supposed to work. Some authors suggest it is particularly helpful for ‘visual learners’.

“There is substantial research on individual differences in learning styles across four dimensions, personality, information processing, social interaction, and instructional methods (Claxton and Murrell 1987), which imply the need to use diverse teaching methods to reach learners with different strengths. One categorization of learning styles includes auditory learners, visual learners, and tactile/kinesthetic learners (Sarasin 1999). Auditory learners may be well-served by traditional lectures, but visual learners need greater visual support and tactile learners need to do things to learn. The construction of a Mind Map provides a learning experience for visual and tactile learners who are traditionally not as well served by lectures.”

The lack of evidence supporting the existence of learning styles or the benefits of fitting teaching to a specific modality led me to wonder whether there was a genuine benefit from teaching students how to mind map as part of revision.

A more valid hypothesis is that it is the act of organising and classifying the information aids retention. There are some plausible reasons to think this might work. For example, in one quite famous study Bower et al (1969) looked at the effect of organising material in a semantic, hierarchical way had upon recall of the material.

“In one of our experiments (Bower, Clark, Winzenz, & Lesgold, 1969), subjects learned four of these 28-word hierarchies concurrently, amounting to 112 words in total. For half the subjects, the words were presented as four complete hierarchical trees…”

“For the control subjects, the same 112 words were presented in spatial trees, 28 per slide, but the words on a given slide were chosen randomly from all levels of the four conceptual hierarchies. Thus, the random lists appeared to have no obvious structural principle.”

The results appeared very strongly to suggest that semantic, hierarchical organisation of material greatly aided recall:

The hierarchical lists in Fig. 8 share many features in common with a simple mind map – so perhaps it is the act of organising the material into semantically meaningful categories when mind mapping which supposedly improves recall?

Some issues of doubt

There are psychologically plausible reasons why mind maps might work as a revision technique, however there are several potential pit-falls with the strategy that may undermine its effectiveness.

One element said to benefit revision is the use of colour-coding and drawings within mind maps. In principle, this might work like highlighting (making the information distinctive) and visual imagery (e.g. creating visual mnemonics) to improve recall. However, there are reasons to doubt whether these strategies are successful in all contexts. For example, Dunlosky et al (2013) reports:

“Five techniques received a low utility assessment: summarization, highlighting, the keyword mnemonic, imagery use for text learning, and rereading. These techniques were rated as low utility for numerous reasons. Summarization and imagery use for text learning have been shown to help some students on some criterion tasks, yet the conditions under which these techniques produce benefits are limited, and much research is still needed to fully explore their overall effectiveness.”

Thus, for all that mind maps may look attractive and certainly keep students looking ‘busy’, there’s no guarantee that the mnemonic techniques employed within mapping will be an effective way to process the material. How do we judge whether the material to be revised would genuinely benefit from visual imagery and colour-coding?

Whilst the role of semantic organisation in the encoding of memory is a fairly well established psychological finding, the benefit of this organisation appears to depend – in part – upon the groups we identify within the material. It appears that once we have organised material into (what is for us) natural groupings, that re-presentation of that material within those groups is recalled better than if those groups have been changed.

Bower again:

“Specifically, if the groupings imposed on the input trial are consistent with the groups the person uses, then his recall should be facilitated; contrariwise, if the input groupings systematically violate or conflict with the subject’s natural groupings, then the input trial should actually reduce his recall.”

Obviously, this is a problem if our students assign key concepts or key words into semantic groups which are inappropriate. In editing or correcting those groups (e.g. through feedback and students revising groups), there’s a possibility that the benefit to recall will be lost.

Thus, like summarising information, the pupil may require a fairly high degree of prior knowledge in order to use the technique effectively. After all, if the student doesn’t really understand the semantic links between key ideas or key words, then it is likely that the ‘natural’ groups they identify will conflict with the factual semantic organisation of the material. This is especially problematic in subjects like science, where often ideas are linked in counter-intuitive ways. Mind mapping without a secure understanding of a topic might simply consolidate any misconceptions that exist or lead to the material being ‘organised’ in a fairly arbitrary way.

Creating summaries of information is a difficult skill. So much so that Dunlosky et al (2013) rate it as a low utility technique.

“On the basis of the available evidence, we rate summarization as low utility. It can be an effective learning strategy for learners who are already skilled at summarizing; however, many learners including children, high school students, and even some undergraduates) will require extensive training, which makes this strategy less feasible. Our enthusiasm is further dampened by mixed findings regarding which tasks summarization actually helps.”

Like probably every secondary school teacher in the UK, I’ve tried to get my students to create visual maps of topics. It’s actually quite hard to get pupils to draw decent visual maps! Beyond the challenge of some pupils wanting to spend forever ‘bubble writing’ the title, it requires quite a significant amount of time and training for students to organise much of the material into a visual form. It is possible, with persistence and practice, to encourage students to create some undoubtedly beautiful and complex visual maps of learning material. However, is it genuinely worth the time and effort in doing so? Do mind maps actually improve the recall of information required in exams?

What does the evidence say?

So widely used are mind map techniques as a revision strategy, I assumed there must be a fair amount of evidence supporting the technique. It proved more difficult to find research evidence than I imagined. @roygrubb helpfully linked me to a wiki list of some of the research into the effectiveness of mind mapping.

At face value, there appears to be some research support for the technique as a revision strategy. However, many of the supporting studies suffer from one or more of the perennial issues within education research. For example, one study reporting benefits of mind mapping appears to lack any kind of counterbalancing or randomisation of control vs experimental groups; the sample size is fairly small (N=86) and the assessment system appears highly subjective – yet there is no attempt at blinding.

“The pretest and post-test essays of both groups were holistically graded based on a general impression of content, organization, cohesion, word choice, language use and mechanics.”

As an evidence base, it appears rather underwhelming support for such a popular educational strategy.  On the other hand, there are a couple of larger, better controlled studies which appear to cast doubt upon the generic effectiveness of mind mapping as a revision method.

In a pair of counter-balanced experiments involving undergraduates, Karpicke et al (2011) compared the effect of retrieval practice vs concept mapping upon test performance. Interestingly they found that students rated the concept mapping activity highly.

“Ninety out of 120 students (75%) believed that elaborative concept mapping would be just as effective or even more effective than practicing retrieval. Most students did not expect that retrieval practice would be more effective than elaborative concept mapping …”

However, the actual effectiveness of the techniques appeared at odds with student perceptions:

“Overall, 101 out of 120 students (84%) performed better on the final test after practicing retrieval than after elaborative studying with concept mapping.”

In another pair of fairly large and reasonably well-controlled experiments, Ritchie et al (2012) looked at the effect of retrieval practice with and without mind mapping on the recall of novel geographical facts.

The results of the first experiment showed a clear advantage for retrieval practice. However, whilst mind mapping was a weaker revision technique, it did appear more effective than note taking.

“Children in the retrieval practice group had significantly higher recall scores four days later than those in the non-retrieval group. The other study technique, mind mapping, did not exert a main effect on learning, but did improve learning compared to normal note-taking in the non-retrieval practice condition.”

However, in an attempt to replicate this effect with a larger sample (209 UK primary school children), the benefits of mind mapping appeared to vanish:

“Children in the retrieval practice condition recalled significantly more facts at the one- and five-week tests, albeit with a smaller effect size than for the four-day test administered in Experiment 1. Experiment 2 did not replicate the interaction between retrieval practice and mind mapping discovered in Experiment 1; mind mapping did not affect learning outcomes in either of the retrieval conditions.”

Their conclusions provide a challenge for the idea that mind mapping is an effective revision method:

“The two experiments reported here have practical implications for primary school teachers: using simple self-testing in the classroom by asking children to make notes on their learning materials from memory should significantly improve their recall of those materials several weeks later. …

“The popular technique of mind mapping, on the other hand, may be an interesting and enjoyable way for children to visually represent their learning, but teachers should not expect it to boost fact learning–at least of the type studied here–in the short- or long-term.”

Post Script

After writing this blog post, @ryandal pointed me towards a more recent study by Blunt and Karpicke (2014)

In this study, the researchers compared repeated study with two types of retrieval practice; creating concept maps and summarising as a paragraph. They found both types of retrieval practice were equally effective ways of fostering long-term recall. They suggest that retrieval practice works simply through the act of retrieving information, rather than the form it is written in.

“The key finding from the present experiments was that retrieval practice was equally effective when done in concept map or paragraph format. Students did not gain additional benefits by retrieving knowledge in concept map format relative to retrieving in paragraph format.”

Interestingly, this undermines the idea that the process of semantically organising the information into a hierarchy improves later recall.

“Concept mapping is assumed to promote organizational or relational processing that should improve learning, but our results are consistent with the possibility that such organizational processing may be redundant with the processing people already engage in when practicing retrieval in other ways.”

So, it appears that mapping techniques aren’t particularly effective when used as a summarising technique, but are no worse than note-writing as a retrieval practice task.

Conclusion [edited 26/08]

Visual mapping of one sort or another is a commonly suggested revision technique, based on the assumption that the process of organising material in linked, hierarchical and graphical ways is superior to note-writing or simply answering practice questions. However, the evidence for its effectiveness as a process of elaboration is currently poor. That’s not to say mind mapping or concept mapping couldn’t be effective for other things – perhaps brainstorming ideas or planning a piece of writing – but the evidence appears at odds with its mainstream use in schools as a graphical summarising strategy.

Recent research appears to suggest that it can effectively be used as a form of retrieval practice (i.e. recall in the absence of the material to be learnt rather than a summarisation technique). However, given that other methods of retrieval practice (e.g. practice questions) may require less training, it could be argued that teachers would be better off encouraging a wider range of retrieval practice strategies (e.g. self-testing using flash cards) in order to help children revise material more effectively. Certainly the claims that creating visually organised representations of information leads to superior learning, appears unsupported by the evidence.