A Tool for Structuring, Exploring and
Summarising Qualitative Information
And a much wider array of information about monitoring and evaluation methods can be found at www.mande.co.uk
This tool makes use of qualitative information. This
information is in the form of important distinctions or difference that people
see in the world around them. Important differences are those that make a
difference. Differences that make a difference can be described as information
The term "tree map" is adapted from the field of
cladistics, a methodology for the classification of living organisms into a
nested hierarchy of categories based on relative commonality of structure (e.g.
species, families, genera etc).
Tree maps help us deal with some problems commonly
encountered when dealing with qualitative information:
- "The Apples and Pears" problem: How to make comparisons
between complex entities. Clue: Locate the choice in a context, and bring the
observer into the picture.
- "The Wood and Trees" problem: How to see an overall order but
also to recognise local detail and diversity at the same time. Clue: Link the
analysis of the macro to the micro.
2. The basic structure
A tree map is a nested classification. It can be
represented as a diagram that grows from a single trunk and ends with many
leaves. A simple example is given below.
3. Generating a tree map
3.1 With a single respondent
Normally this method is used with one respondent. Some
ways of using it with more than one person are discussed in section 3.2 below.
- Identify the respondent’s area of expertise or knowledge that
you want to explore. For example, knowledge of animal diseases held by a
paravet, or knowledge of local NGOs held by a NGO staff member working on NGO
- Generate a list of actual cases which contains a wide variety
of examples. For example, a list of cases treated by the paravet in the last
month, or a list of NGOs known to the NGO staff member. Aim for at least twenty
case and ensure there is variety. Write the name of each one down on a separate
card. Cases might be events (treatment provided) or entities (clients).
- Place all the cards in one pile (the trunk of the tree) and ask the
respondent to tell you about some of the differences between all these cases.
The purpose of this question is simply to generate awareness of the large
number of differences that exist.
- Ask the respondent to sort all the cards into two piles of any size
(the first two branches above the trunk), according to what they think is the
most important difference between all the cases represented on the cards.
Emphasise that it is their opinion of "importance" which is important. There is
no intention or requirement here to generate an "objective" description. If the
project has an overall goal then the facilitator could, if they want to, refer
to that goal as a general reference point, without necessarily spelling out the
specifics of that goal.
- Emphasise that a distinction is important if it makes a difference.
Because respondents may casually offer a difference simply to oblige the
interviewer it is important to check its significance by asking "What
difference does this difference make ?" If one can’t be identified
suggest to the respondent they consider if there are other differences which
might be more important.
- Write down a description of the reported difference at points
B&C. Take each pile at B&C in turn and repeat stage 4 above. Repeat
this process with all piles until there is only one example left in each pile.
These become the leaves of the Tree Map
- In some cases there may be more than one example left in a pile but
the respondent may not be able to identify an important difference between
them. Don’t force them to do so, but simply note that no further
difference could be identified. It may be useful to do all the above steps in
the order of the groups of cards that the respondent feels they know most about
first, and least about later.
3.2 With multiple respondents
There are at two basic alternatives: (a) working with a
whole group, and (b) working within individuals and then comparing their
individual tree maps.
The first group-based approach is relatively
straightforward. Simply outline the process above (3.1) to the group, and let
them discuss the matter before making a series of collective choices.
The second approach is more structured and thus more
time consuming. There are two different options.
- Compare different applications of the same classification
scheme (tree map)
- Present respondent A's tree map to a second respondent (B), with
the difference labels attached to each branch, but without the names of
the cases found at the end of those branches, at each leaf.
- Give the cards containing all the cases to respondent B.
- Ask them to proceed from the trunk upwards, sorting the cards
according to the differences already labelled on the tree by respondent B,
according to where they feel each card should go. Allow them to introduce
additional cases if they feel that none of the cards on the existing set fit
some of the branches.
- Compare the overlap of the two sets of classifications by
visually and in terms of the percentage of common cases, out of the total
number of cases used.
Ideally, with two people working in the same
situation and having the same responsibilities there should be a strong
correlation between the two sets of classifications made on the same tree
- Compare different interpretations of the same classification
- Present respondent A's tree map to a second respondent (B),
without the difference labels attached to each branch, but with
the names of the cases found at the end of those branches, at each leaf.
- Place the differences listed at each junction on the tree by
respondent A onto a second set of cards.
- Ask them to proceed from the trunk upwards, placing the
difference cards on whatever branches they think are suitable. Allow them to
introduce additional differences if those already on the cards given to them
don’t seem to fit.
- The two structures can then be compared visually, and in terms of
the percentage of common differences, out of the total number of distinctions
Some progress has been made within the field of
cladistics in enabling statistical comparisons of similarity between different
3.2. Using Tree Maps
3.2.1 General uses
Value can be obtained from Tree Maps at two stages:(a)
during the creation of the Tree Maps, and (b) through comparisons made between
parts of the structure once it has been created.
1. During creation of a Tree Map the main use is as a
enthographic tool: understanding people's view of the world. There are
two forms of usage:
Identifying the distinctions that people see as
important. This is evident in the differences cited, and the differences
they are seen to make. It is also evident in how early in the exercise they are
cited. The method makes use of binary classifications (two sub-categories only
at any one time). This forces the respondent to prioritise, to choose between a
number of potentially important distinctions. There is a common sense caveat
here: What you hear will be context dependent (especially on the perceived
nature of the relationship between interviewer and respondent). But differences
that respondents cite, but may not believe are important, may be harder for
them to explain (what difference they make). This helps make them detectable.
Identifying the limits to people's knowledge:
When respondents cannot identify differences between two or more entities the
limits to their knowledge seem to have been reached. Not knowing what people
know about can be important, especially when they might be expected to, or
claim to have, expertise in that area.
2. After creation there are two other types of usage.
One is based on proceeding from trunk to leaf, the other is based on proceeding
from leaf to trunk.
Planning based discussions: Starting from the
trunk, respondents can be asked questions such as "How will your work in the
next six months with this group be different, compared to this group (those
labelled at the first junction)?" Then move to the next junction on each
branch, one a time, and re-iterate the same question. Lack of a difference
suggests lack of a strategy, and points to areas where it may need to be more
articulated. Other related planning questions which can be asked, from trunk to
branch, are "Which of these will be the most immediate priority?", "Which of
these will you be spending the most time with ?", "Which of these will present
the most problems?", Which of these do you want to scale up / expand ?", etc.
The answer, and associated rationale, can be added as a further annotation to
the tree map, at the appropriate junction.
Evaluation based discussions: These proceed
in the opposite direction, from leaf to trunk. Starting from two adjacent
leaves respondents can be asked questions such as " Which of these two groups
was most successful in the last six months?". Then move to the next two most
adjacent leaves and re-iterate the same question. Then compare the two leaves
which were identified as the most successful and which share the same larger
branch. Reiterate the process again with the other leaves. In each case "move"
the most successful case down the tree to the next junction, to meet the most
successful case moved down from the next most adjacent branch. As above, the
choice, and associated rationale, can be added as an extra annotation to the
tree map, at the appropriate junction.
Success overall can be defined in two ways. At any one
junction it will be in terms of which of the two types that exist there (as
represented by particular cases). The types take on a wider generality and
relevance the closer they are to the trunk. When viewed in terms of particular
cases (examples) success could be seen in terms similar to a tennis tournament.
The number of grades of success or performance would equal the number of
junctions along a branch from trunk to leaf. In the diagram above there are
three, beyond the original leaf itself. Comparisons would need to take into
account the fact that some branches may be longer than others.
3.2.2 Specific Applications
- Assessing the impact of capacity building activities: When
supporting capacity building work with individuals or whole organisations, we
might expect that this assistance, either in the short or long term, would make
a difference to the person or organisations relationships with their clients.
One attribute of that relationship is responsiveness. The service provider
might be more sensitive to the differences between client’s needs. They
may also be more up to date in their knowledge about their various clients'
needs. The important differences they see between their clients (that they
think are important) may be more reflective of their clients concerns, and not
just their own. Much of this information is available, in the first instance,
in the form of knowledge the service provider has (or does not have) about its
clients. This knowledge is in effect a proxy indicator. Tree maps are a way of
mapping a service provider's knowledge of their clients. How differentiated is
their map of the differences between clients, how up to date is their knowledge
of each "leaf" and branch? How much do the descriptions of difference reflect
client versus provider concerns? This information can be verified by
independent observation and follow-up contacts with clients. Are services
visibly differentiated (rather than homogenous)? How frequently have they been
modified? Do clients views on relative value of services provided correlate
with those of the provider?
- It should be possible to use Tree Maps as a means of doing a
stakeholder analysis in a development project. This could initially be
from the perspective from one observer, possibly an individual stakeholder.
Firstly, a list of cases reflecting the maximum possible variety of
stakeholders would be identified. The process would then start at the trunk,
with the respondent identifying "the most important distinction between all the
stakeholders in the project". Then each initial category of stakeholder could
be progressively differentiated until all cases were located as a leaf of their
own. Alternately the analysis could be attempted without prior naming of
specific cases, and then differentiated to the degree of detail that was
- An alternate process would make use of multiple participants,
involved on a rolling basis. The first respondent, (possibly the one person
seen as the most important) would be asked to identify the first branch in the
tree. People identified as most representative of each of those two branches
(possibly by the first respondent) would then be asked to identify the next two
branches (x2), from their point of view. People representative each of those
branches (x2) would then be asked to identify the next two branches (x4), etc.
Some branches may join back together again, when the same person is identified
as a representative of an important sub-group by two different branches of the
tree that has been developed. This should not be a problem. It makes the tree
more heterarchical than hierarchical, and provides more flexibility of
interpretations when, and if, experiences is aggregated back down the tree
structure to the trunk
- Scenario planning: This is a practice widely associated with
Shell. It involves developing a number of alternate views of the future and
then identifying how the organisation concerned would react differently to each
different scenario. Tree maps of different scenarios could be developed by
starting off with a question: "What is the most important difference in views
within this organisation about what it should be doing over the next 10 years
?". Within each new branch created by the answer, the question could be
repeated, but pre-phrased in terms of "Within this view of the future...". Once
the Tree Map is constructed a planning based set of questions could be pursued,
as described above. As above, both individual and group based versions of this
exercise could be designed.
- Qualitative monitoring: A staff member of an NGO may be
working with many groups or villages. Their categorisation of these groups or
villages can be documented using the tree map method. This structure then
provides a framework within which comparisons can be made by that person
between the different items of news they may have heard from each of these
locations. News is defined here as a form of difference, a change from the
previous condition. News from two sources on immediately adjacent branches can
be compared in terms of its relative importance, as seen by the observer (the
NGO staff member who owns the classification). The most important news (thus
defined) can then be compared to the most important news from the next most
adjacent branches. Complex information can be managed by making one-at-a-time
comparisons. Comparisons will start at a very local level (adjacent leaves) and
move to towards more global comparisons (branches next to the trunk). In
organisations the organogram itself can form a similar type of tree structure
and be used for the same purpose. A participatory monitoring system involving a
large number of staff, designed on the this basis is described in a paper
available at http://www.mande.co.uk/docs/ccdb.htm Another related system is
described at http://www.swan.ac.uk/cds/rd/diversity.htm
If you are interested in using this tool in any setting
I would be happy to provide informal advice and comment. For further
information or permission to reproduce this paper email Rick Davies at
...The information I collected through M&E news before I came away
has been very useful - good case studies and ideas.
In particular I thought I would let you know that I have tried your tree
map method for the first time. Despite thinking it sounded rather unlikely to
be useful when I first read it, it has provided a very nice alternative to
classic wealth ranking for investigating the structure of villages. The people
I am working with had the same unease as I do about launching into wealth
analysis. We therefore tried your method as it seemed to offer a way round the
problem. We ask the number of families in the village, then ask about
differences between them with respect to livestock and well-being. Following
the process as you describe, we rapidly get a good idea of the wealth structure
of villages, which is far more disparate than I had imagined. From this
exercise it is possible to find people to interview in more detail from each
category. Repeating the exercise with paravets, we then asked them to indicate
what proportion of their work was with which group. This worked well and
provided an indication of who was benefiting most from the services of the
programme." Stephen Blakeway, Vetwork UK, at
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