Hi there - William H Whyte's work including his book, The City: Rediscovering the Center is full of ideas on this - backed by his own research, mostly in New York City.  There's more information on his work at http://www.pps.org/reference/wwhyte/

Hope that helps.

In addition to the factors mentioned above,  a planner must first conduct a survey to determine the recreation culture of the people who will use the open spaces. Herbert Gans, the great Sociologist,  argues that if the users are not involved in the planning/design stage, three things are going to happen. First,  facilities provided may be put to awtong use (e.g. refuse dumping site); second the openj space may never be usef; d

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Hi Ryan - Sorry, but my answer above was suddenly disrupted yesterday. Let me continue from where I stopped:

First, the facilities provided may be put to a wrong use (e.g. the open space(s) may become a refuse dumping site); second, the open space(s) may never be used. Third, the facilities may be underutilised. Furthermore, the planner must consider such principles as: equity, efficiency, flexibility and sustainability when designing the open spaces.

Thanks Matt & Jacob, much appreciated.

Hi Ryan,

As Jacob has already stated, the question of who the space is supposed to be for is important. A lot of green spaces do not cater for the needs of the diverse people living in cities.

Have a look at Byrne, J., & Sipe, N. (2010). Green and open space planning for urban consolidation – A review of the literature and best practice. Urban Research Program, Griffith University.

Another line of thought relies less on planners knowing what's right. Have a look at these works:

Franck & Stevens, Loose space: possibility and diversity in urban life. (2007). Abingdon: Routledge.

Campo, D. (2013). The Accidental Playground. Fordham University Press.

My research in this direction suggests informal green space already plays a role for residents, and there may be a substantial amount present in our cities smart planning could tap into. I've attached some material below.

I hope this helps!

Article Informal Urban Green-Space: Comparison of Quantity and Chara...

Article Informal urban greenspace: A typology and trilingual systema...

Conference Paper Appreciation of informal urban greenspace by Japanese and Au...

Thanks Christoph, great response.

Simple realy ... Plenty of natural affordances .... Great for across all age groups for physiclal and psychological health ... Has form and function .... Can be utilised by the local population if they want to get their hands dirty!!!

Hi Ryan - I would like to add 'liveability' as an important factor which may include many other sub-factors in it. The term is one of those which is currently being used as a hot topic in the urban design and planning agenda, thought the meaning needs to be contextualised considering all the factors involved (i.e. physical, environmental, cultural, political and so on) in formation of a public space. Such liveable places are those which would continue to thrive even when face with  demographic/cultural changes of their users, or political changes in the approach of the relevant stakeholders toward them, or even with the change on the land-use allocations in a city. There is an interesting recent read on liveability in Guardian cities which focuses on the work of Jan Gehl and might be interesting for you:

http://www.theguardian.com/cities/2014/dec/08/jan-gehl-make-cities-liveable-urban-rethinker

Open spaces and ample greenery.

This may be of interest -- for the public space of streets in cities:  From a piece I am just finishing on the value of built environment based on occasion and image:  a summary of  policy recommendations:

Downtown Revitalization Guidelines / Policies

---> Street profile:

Preserve perceived existing / ‘old’ street profile

Consistent street profile proportion:

Through stepback of higher structures above

e.g. 2-3-story roof lines

High rises at property line destroy street profile

Suggested regulation: Stepback, not height limits

---> “Small grain’ sequence / network of elements

and occasion opportunities at sidewalk level

---> Assign floor space at sidewalk level to

‘high frequency visitor destinations’

Suggested regulation: Incentives for high visitor

visitor frequency use of ground floor

Encourage alternative means for alerting

Public to entities at higher levels, courtyards,

Passages: e.g. /showcases on sidewalk

---> Continuous string of appealing / interesting

destinations / occasion opportunities

Avoid interruption of occasion string by blank walls,

Parking garages, glass walls without interesting

content behind (empty lobbies, offices)

---> Encourage continuous arcades, awnings

(Protection against rain, sun)

---> Encourage sidewalks with different ‘zones’:

- showcases, displays or restaurant seating

- walking

- freestanding showcases, plants, trees

(separating walking zone from traffic)

---> Encourage using street slopes to generate two or more ‘street level entry’ floors

---> Encourage developing stepback ‘roof’ areas to become secondary pedestrian levels (connecting such levels with pedestrian bridges across busy streets)

A paper explaining the detailed development of value measures based on the concepts of occasion and image is available (I can send it to regular email addresses as pdf attachment upon request, let me know at [email protected]) as well as  a 'tavern talk' discussion of these ideas -- without equations and math -- on the same issue.

Mixed use and enhancement to the "public good" can be achieved by increasing the permeability of space, leading to spatial equity. Jane Jacob's "line of sight" is a good approximation of the "neighborliness" of a public space.