# Association Maps

• Concept Maps »

Heirarchical maps including  information about relationships between concepts.

• Association Maps »

Non-linear maps using a standard data representation to explore and catalogue relationships between concepts.

• Mind Maps »

Visual maps showing simple links between concepts.

# Association Maps - making relationships work

## Association maps focus on the relationship between two concepts, and use symbols to indicate the most common relationships. Additional concepts may be added producing a non-linear structure similar to a mind map, whilst the use of additional language on the link is more reminiscent of a concept map.  The diagram below illustrates the main features.

The map above can be read in any order, starting in any position. Any two concepts joined by a link (line) can always be made into a sentence, so a simple way into an association map is to pick such a triplet (two boxed words and the linking line) and try to read it.

## Dogs and Fleas

Look at "Dog" and "Flea" on the map. These are joined by a link with the word "has" along the top. The "has" has a small black arrow pointing towards the "Flea", showing the direction in which the association should be read. This triplet can thus be turned into the sentence "Dog" "has" "Flea", or "A dog has a flea". In association maps the singular is always used for concepts (the words in boxes), so the triplet could equally well be read as "Dogs have fleas".

How many? - Sometimes the number is important, and in an association map it is possible to include this information by adding optional numbeers to the end of the link nearest to the concept which has the value. In the link under discussion here the "1" relates to the "Dog", whilst the "0..*" relates to the "Flea". Here "0" means there may be none and the asterisk (*) indicates "many". Other examples might include "1..2" (the number could be 1 or 2) or "1..*"

(one to many, or "one or more"). In full then, this triplet tells us that " One dog has between zero and many fleas".

## Common Relationships

On association maps links always give additional information about the relationships between the two linked concepts. There are two particular relationships which are very common and so these have their own symbol to reduce clutter on the maps.

"Is a type of" or Specialisation Relationship - this is represented by a large white arrow on the end of a link, as in the example between "Terrier" and "Dog". The arrow points towards the more generalised concept, and anything which is true of the more generalised concept (in this case that it is made of a tail, legs and a head) is also true of the specialisation. In this case anything which is true for "Dog" would also be true for "Terrier". This is not a two way relationship, so some things which are true for "Terrier" are not also true for all dogs. The easiest way to form a sentence structure form a triplet with this type of link is to read from the tail of the arrow to the head, so "Terrier" "is a type of" "Dog", however it can also be read in the other direction as "Dog" " has type" "Terrier".

"Is made up of" or Aggregation Relationship - This is represented by a large white arrow on the end of a link and often involved a numbr of triplets with the same relationship to the main concept. There is a hierarchy here as this relationship shows how a concept can be broken down into smaller components. At a simple level on the diagram, this symbol is used to show how "Dog" "is made up of" "Tail" x1, "Leg" x4 and "Head" x1. The {incomplete} notation indicates that this is not the full specification for a dog. As with the numbers, this is optional depending on the purpose of the map. If we stick to the "triplet = sentence" conversion, then this area of the map would translate as three sentences. "Dog" "is made up of" "Tail" x1. "Dog" "is made up of" "Leg" x4. "Dog" "is made up of" "Head" x1. However, these aggregation relationships usually lend themselves to being collated to produce "A dog is made up of a tail, four legs and a head".

Association Relationship - This is the type of link used for relationships which do not fall into the above category. The "Dog has fleas" example above is an association relationship. The exact wording used along the link in these cases is up to the map developer. The relationship between fleas and dogs could equally well be described as "Fleas live on a dog", in which case the "has" term would be replaced with "lives on", and the small arrow would be moved to the right of the term and point towards "Dog".

## References:

Jon Holt (2004). "UML for Systems Engineering - watching the wheels." The Institution of Electrical Engineers.

Martin Fowler (2004). "UML Distilled - a brief guide to the standard object modelling language." Addison-Wesley.

Jon Holt (2005). "A Pragmatic Guide to Business Process Modelling." The British Computer Society.

## This website gives an overview of three visual mapping options, concept maps, mind maps, and association maps, to support an understanding of the differences between them, and to help visitors to select the option best suited to their needs.

The author approaches the topic from a secondary science teaching background, coupled with a spell using graphical mapping techniques to support process modelling in a business environment.