All Year concerns persistence.
Does the link always exist?
Does it exist only at certain times?
Does it appear and disappear?
Does it depend upon a timetable, season or external condition?
The phrase All Year is deliberately memorable rather than literal.
The underlying question is:
How stable is this connection through time?
Permanent links
Some relationships are effectively permanent within the context being considered.
London is the capital of the United Kingdom.
Paris is in France.
The Beatles originated in Liverpool.
These links do not depend on the time of day or season.
They are highly persistent.
Scheduled links
Other relationships exist only because a service operates.
London and Paris may be permanently connected geographically and historically, but the practical rail connection depends upon trains actually running.
At 10 a.m., there may be several available services.
Late at night, there may be none.
The infrastructure remains.
The usable transport link temporarily disappears.
This means that one pair of entities can simultaneously have:
a permanent geographical link
and a time-dependent operational link.
Frequency
All Year also includes frequency.
A Metro station connected by a train every two minutes has a stronger practical link than one served twice a day.
Two airports may be connected by a flight, but if that flight operates only once a week, the operational link is relatively weak.
Frequency therefore affects the temporal quality of a connection.
We might ask:
Is it continuous?
Frequent?
Daily?
Weekly?
Occasional?
One-off?
Seasonal links
Some connections are seasonal.
A ski resort may have a much stronger transport network during winter.
A seaside town may have additional services during summer.
A migratory bird may connect two continents at different times of the year.
A Christmas market may connect a town square to a particular activity only for several weeks.
These are genuine links, but they are not permanent.
Temporary links
Some links exist for an even shorter period.
A diversion creates a temporary bus route.
A footballer joins a club on loan.
A road closes.
A band performs at a venue for one night.
A city hosts an Olympic Games.
The link may be strong while it exists but disappear completely afterwards.
This means that durability and strength are not the same thing.
A temporary link can be extremely powerful.
London and Paris
London and Paris provide a useful example because the same relationship can be examined through all three qualities.
Near
At a European scale, London and Paris are close major capitals.
The physical distance is modest compared with distances across the continent.
The high-speed rail connection further reduces the practical distance between them.
Clear
The connection is easy to understand.
They are neighbouring European capitals with longstanding political, economic and cultural relationships.
They are also joined directly by rail through the Channel Tunnel.
The route can therefore be seen, travelled and explained.
All Year
The relationship between the cities is permanent, but particular forms of connection are not.
The cities do not stop being linked when the last train leaves.
But the ability to travel directly by rail depends upon operating hours, schedules, disruption and frequency.
So All Year distinguishes between:
the enduring relationship
and
the availability of a particular route.
London and the United Kingdom
London and the United Kingdom demonstrate a different kind of link.
They are extremely Near in relational terms because London is contained within the United Kingdom.
The link is also extremely Clear.
But Move behaves differently.
There is no journey:
London → United Kingdom
because London is already inside the United Kingdom.
Instead, the operation required is Zoom.
We move from:
London
to a wider geographical frame:
United Kingdom
This is not traversal.
It is a change of scale.
That distinction helps demonstrate why Move and Zoom need to remain separate operations within Linkology.
Comparing London with other cities
Near and Clear are always contextual.
London may have an extremely clear relationship with Paris.
But its relationship with Birmingham, Manchester or Liverpool may be even clearer in some contexts because all four are major English cities within the same national system.
A railway map might make London–Birmingham especially clear.
A history of popular music might make London–Liverpool more significant.
A discussion of international capitals might make London–Paris the more obvious pairing.
There is therefore no universal measurement of link quality.
Near, Clear and All Year describe the relationship within a particular frame.
Change the frame and the assessment may change.
This is another reason why Zoom matters so much.
Three independent dimensions
Near, Clear and All Year should not be combined into a single crude score.
They describe different properties.
A link can be:
Near, Clear and All Year
such as two adjacent stations permanently connected on a transport network.
It can be:
Near, Clear but temporary
such as neighbouring festival stages during an event.
It can be:
Near but unclear
such as two people who lived on the same street without any widely known relationship.
It can be:
Distant but clear
such as London and Sydney as major world cities connected by direct air travel.
It can be:
Clear but seasonal
such as a ski resort and a winter shuttle service.
The usefulness lies in examining the dimensions separately.