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Cited by 11Urban Design and Spatial AnalysisComplex Network Analysis TechniquesUrban Transport and Accessibility

A Network Approach to Link Visibility and Urban Activity Location

Open access
Natapov, Asya, Czamanski, Daniel, Fisher-Gewirtzman, Dafna·2018·Networks and Spatial Economics
DOI 10.1007/s11067-018-9411-4
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Abstract

Performance of a range of urban amenities is influenced by their accessibility to pedestrians. Success in attracting pedestrians to a particular location depends on how they project visuospatial information. In this paper, we propose an original method for analysing the visuospatial integration of particular locations within a street network. As a case study we analyse the distribution of one type of urban amenities - food and drink public facilities. We represent them in a form of visibility graph as objects of navigational decisions within the street network. To explore how urban facilities, streets and pedestrian visual cognition are interrelated, we create and compare three cases: a street network visibility graph and two visibility graphs of amenities. The first graph is based on the existing, “natural” distribution, while the second is an “artificial”, fabricated version of the environment, where urban locations are redistributed evenly across the case study. We study the graphs’ global network properties by the use of small-world, and scale-free models. Our results demonstrate that views available for an urban traveller in the existing, “natural” setting had a particular structure. It is built of numerous weakly connected locations coexisting with a small number of hubs with an exceptionally large number of visual connections. Such organisation of urban visibility shows that visuospatial network shares morphological similarities with other natural networks, suggesting that common organizational principles underlie network structure.

AI snapshot

Written from the paper’s full text.

TL;DR

The paper proposes an integrative visibility graph (IVG) that combines street-network decision points and food/drink “third places” to analyze visuospatial integration in Tel Aviv-Yafo. Comparing natural and artificially uniform distributions, it finds all three visibility graphs are small-world, while the natural IVG shows a more heterogeneous, power-law-like tail than the artificial one.

Key findings

  • All three graphs—SNVG, natural IVG, and artificial IVG—exhibit small-world properties (S > 1); average path length is higher than in corresponding random graphs and lower than in regular graphs, while clustering is close to regular graphs.
  • Under least-squares fitting, only the natural IVG degree distribution is power-law-like; under the Clauset et al. (CSN) method, none of the distributions is fully scale-free, but their tails fit power laws. The natural IVG likely scale-free tail consists of nodes with degrees 18 to 66, versus 12 to 31 for the artificial IVG; SNVG has a relatively heavier likely scale-free tail of 39% of nodes.
  • The natural IVG has 526 nodes and 4172 edges; the artificial IVG has 526 nodes and 5000 edges. Despite fewer edges, the natural IVG produces a more heterogeneous visibility pattern with high “peaks,” whereas the artificial even distribution produces more homogeneous patterns.
  • In the natural IVG, group A (likely scale-free tail) is 34% of locations (177 out of 526) with degree higher than 18; group B is 66% (349 out of 526) with degree less than 18. Sample locations have 66 and 42 visual connections in group A, versus 3 connections each in group B.

Methods

  • Case study: historical centre Lev Ha’Ir, Tel Aviv-Yafo, Israel; 217 food and drink public facilities with street seating, collected in a manual survey. Three graphs were built: SNVG (309 nodes, 1338 edges), natural IVG (526 nodes, 4172 edges), and artificial IVG (526 nodes, 5000 edges).
  • Artificial case: the same 217 “third places” were redistributed as uniformly as possible using 217 active grid cells, with cell size calculated as 113 m/85 m, and manually placed according to urban morphology and spatial logic. The IVG was built in MATLAB as an undirected visibility matrix linking street decision points and activity locations if their line of sight does not intersect building contours.
  • Analysis used Gephi: small-world properties via average path length L, clustering coefficient C, and S-statistic; scale-free properties via degree distributions using least-squares fitting and the Clauset et al. (2009) power-law fitting method.

Limitations

  • The paper states that the IVG is limited to a two-dimensional representation and ignores additional factors affecting visual perception, including distance, size, colour, shape, texture, complexity, and atmospheric conditions. It also states that tests are performed only on three cases and suggests expanding to additional urban environments with diverse morphologies.
  • The paper states case study biases. Evident from the text: the study covers one city district and one amenity category (“third places”), limiting generalizability; the artificial redistribution required manual placement, which may introduce subjective choices.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1007/s11067-018-9411-4

Cites

52 of 52 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

19 of 59 cited sources checked · 7 supported · 2 flagged · accuracy not yet measured

  • Premisecitation

    When streets are represented as nodes and edges corresponding to individual streets and street intersections, or by named-based and angularity-based methods, small-world properties are observed.

    “But when streets are represented as nodes and edges corresponding to individual streets and street intersections, or by named-based and angularity-based methods, the small-world properties are observed (Jiang et al. 2014;Porta et al. 2006;Jiang and Claramunt 2004).”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites Jiang et al. 2014 source

      Section 2.1 (p. 2) represents individual streets as nodes and their intersections as edges. Section 3.3 (p. 10) reports striking small-world properties for the original networks. The paper does not establish the claim for name-based methods; its street-construction method joins adjacent segments using an every-best-fit principle. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites Porta et al. 2006 source

      The Conclusions (p. 22) describe a dual representation with streets as nodes and intersections as edges, and report small-world properties generally, with exceptions for networks with few triangular loops. The Results (p. 19) identify four of six networks as small-worlds. Section 2 (pp. 4–5) describes the named-street approach as another method, but this paper does not show that its named-street representation exhibits small-world properties. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites Jiang and Claramunt 2004

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Findingown data

    Views available for an urban traveller in the existing, natural setting had a particular structure: numerous weakly connected locations coexisting with a small number of hubs with an exceptionally large number of visual connections.

    “Our results demonstrate that views available for an urban traveller in the existing, Bnatural^setting had a particular structure.It is built of numerous weakly connected locations coexisting with a small number of hubs with an exceptionally large number of visual connections.”
    Quote in the paperSubstantial claim
  • Findingown data

    The natural 'third places' make a significant contribution to achieving a higher degree of overall visibility.

    “In Fig. 7a we highlight the peaks to show the significant contribution of natural 'third places' in archiving higher degree of overall visibility.”
    Quote in the paperSubstantial claim
  • Findingreasoning

    Strictly speaking, the CSN method does not show that a likely power law behaviour of the natural IVG is more plausible than the other graphs.

    “So strictly speaking the CSN method does not show that a likely power law behaviour of the natural IVG is more plausible then the other graphs.”
    Quote in the paperNot a substantial claim
  • Findingown data

    The artificial, even distribution produces more homogeneous patterns, despite the bigger number of connections.

    “Nevertheless, the artificial, even distribution produces more homogeneous patterns, despite the bigger number of connections.”
    Quote in the paperSubstantial claim
  • Classified as probably not a substantial claim. 43
  • May combine two claims. 35
  • The quote only partly states this claim. 1

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Several studies found scale-free degree distributions in street networks using other graph representations.

    “Several studies also found scale-free degree distributions in street networks, using other graph representations (Cardillo et al. 2006;Carvalho and Penn 2004;Porta et al. 2006).”
    Quote in the paperNot a substantial claim3 of 3 sources checked
    • cites Cardillo et al. 2006 source

      Cardillo et al. represent street intersections as nodes and streets as edges (Introduction, p. 1). In Graph local properties (p. 4), they say they do not expect scale-free degree distributions in these planar street networks because spatial embedding limits node degree; they do not report finding one. (LLM, conf=0.90)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
    • cites Carvalho and Penn 2004 source

      The paper describes axial maps as a representation of streets (p. 2), but its Abstract (p. 1) and section 2.2 (p. 4) report power-law distributions of axial-line lengths, not scale-free degree distributions. Thus it supports the use of another street representation, but not the finding attributed to it. (LLM, conf=0.79)

      Experimental — accuracy not yet measured
    • cites Porta et al. 2006 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The comparative investigations in Cardillo et al. 2006 and Porta et al. 2006 reveal scale-free degree distributions for the vertices of spatial graphs if the ICN principle is implemented.

    “The comparative investigations in (Cardillo et al. 2006 andPorta et al. 2006) reveal scale-free degree distributions for the vertices of spatial graphs if the ICN (intersection continuity negotiation) principle is implemented.”
    Quote in the paperNot a substantial claim2 of 2 sources checked
    • cites Cardillo et al. 2006 source

      In “Graph local properties” (p. 4), Cardillo et al. say they do not expect scale-free degree distributions in their planar street networks because spatial embedding limits the number of streets at an intersection. The Introduction (p. 1) defines their graph vertices as street intersections; it does not describe an ICN-based result that would support the cited claim. (LLM, conf=0.88)

      Checked by a reasoning model — may be wrong.

      Experimental — accuracy not yet measured
    • cites Porta et al. 2006 source

      The Conclusions (p. 22) describe ICN as the method for constructing dual urban-street graphs and report power-law degree distributions, especially for networks of significant size. The degree-distribution analysis (pp. 14–16) finds clear scale-free behavior in the larger graphs but says the smaller graphs do not permit a precise conclusion. The claim overgeneralizes this finding to spatial graphs whenever ICN is implemented. (LLM, conf=0.88)

      Experimental — accuracy not yet measured

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    The primary graph method represents junctions in street networks as nodes, and the street segments that connect junctions as edges.

    “This method represents junctions in street networks as nodes, and the street segments that connect junctions as edges (Eichler et al. 2013;Strano et al. 2012 andBarthelemy 2011).”
    Quote in the paperSubstantial claim2 of 3 sources checked
    • cites Eichler et al. 2013 source
    • cites Strano et al. 2012 source
    • cites Barthelemy 2011 source

  • Classified as probably not a substantial claim.

    Premisecitation

    Relationships between spatial components (street network, urban locations, visual information) are systematized by use of mathematical graphs.

    “In urban studies, relationships between these spatial components are systematized by use of mathematical graphs (Ducruet and Beauguitte 2014;Barthelemy 2011).”
    Quote in the paperSubstantial claim2 of 2 sources checked
    • cites Ducruet and Beauguitte 2014 source

      In “Network analysis in geography and regional science” (page unavailable), the review says transport geographers apply graph theory to networks such as roads and railways. “Local determinants of centrality” (page unavailable) describes an analysis treating streets as nodes and crossroads as links, and “Interdependent networks” discusses graph-theoretic analysis of links among cities. These passages support the use of graphs for street and urban relationships, but do not address visual information as a spatial component. (LLM, conf=0.83)

      Experimental — accuracy not yet measured
    • cites Barthelemy 2011 source

      The road and street networks section (p. 18) describes a street network as a graph of roads and intersections. The urban commuters section (p. 15) also describes a network whose nodes are urban locations and whose edges represent movement between them. The passages found do not show visual information being represented this way, so that component is unsupported. (LLM, conf=0.83)

      Experimental — accuracy not yet measured

  • Classified as probably not a substantial claim.

    Premisecitation

    Small-world and scale-free properties allow classifying different networks in terms of their robustness, efficiency and heterogeneity.

    “Small-world and scale-free properties allow classifying different networks in terms of their robustness, efficiency and heterogeneity (Barthelemy 2011;Newman 2010).”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites Barthelemy 2011 source
    • cites Newman 2010 source

  • May combine two claims.

    Premisecitation

    Traditional, geometric, road-based models fail to observe small-world properties, while a new street-based modelling approach has obtained opposite results, by observing small-world properties for diverse methods of graph representations.

    “While traditional, geometric, road-based models fail to observe small-world properties, a new street-based modelling approach has obtained opposite results, by observing small-world properties for the diverse methods of graph representations, e.g., (Jiang et al. 2014;Jiang 2007;Porta et al. 2006;Jiang and Claramunt 2004).”
    Quote in the paperNot a substantial claim3 of 3 sources checked
    • cites Jiang et al. 2014 source

      The Introduction (p. 2) distinguishes geometric junction-and-segment networks from street-based topological networks and says previous studies found small-world properties in the latter. It does not say geometric road-based models fail to show small-world properties, or establish that the finding holds across diverse graph-representation methods. The Methods (p. 2) describe one street-based representation applied to six cities. (LLM, conf=0.86)

      Experimental — accuracy not yet measured
    • cites Jiang 2007 source

      The Introduction (p. 1) says the traditional segment-and-junction representation is unsuitable for uncovering network patterns, but does not establish that it fails to show small-world properties. The Topological Analysis (p. 4) finds small-world structure in all 40 networks studied using street–street intersection topology; it does not demonstrate that result across diverse graph-representation methods. (LLM, conf=0.84)

      Experimental — accuracy not yet measured
    • cites Porta et al. 2006 source

      The Results (p. 19) find small-world properties in four of six street-based dual graphs, while the Conclusions (p. 22) describe exceptions and caution that small-world scaling needs further investigation. The paper does not establish that traditional road-based models fail to show small-world properties, or demonstrate the result across diverse graph-representation methods. (LLM, conf=0.86)

      Experimental — accuracy not yet measured

  • May combine two claims.

    Findingcitation

    According to the method suggested by Clauset et al. (2009), all the networks are not scale-free, but their tails are.

    “In our examination according to the standard least-square fitting method, only the natural IVG was a scale free, while according to the method suggested by Clauset et al. (2009) all the networks are not scale-free, but their tails are.”
    Quote in the paperSubstantial claim1 of 1 sources checked
    • cites Clauset et al. (2009) source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The evolution of social and economic life in cities increases with population size: wages, income, gross domestic product and bank deposits scale superlinearly, over different years and nations, with statistically consistent exponents.

    “The evolution of social and economic life in cities increases with population size: wages, income, gross domestic product and bank deposits scale super linearly, over different years and nations, with statistically consistent exponents (Bettencourt et al. 2007;Andersson et al. 2006;Florida 2004;Barabasi and Albert 1999).”
    Quote in the paperNot a substantial claim2 of 3 sources checked
    • cites Bettencourt et al. 2007 source
    • cites Andersson et al. 2006 source

      The Model validation section reports a linear relationship between population and land value for Swedish clusters, not superlinear scaling of wages, income, GDP, or bank deposits. Searches for those measures and for consistent exponents across years and nations found no passage addressing the attributed finding. (LLM, conf=0.78)

      Experimental — accuracy not yet measured
    • cites Florida 2004

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    Traditionally complex network theory explains the evolution of scale-free phenomenon by 'growth' and 'preferential attachment'.

    “Traditionally complex network theory explains the evolution of scale-free phenomenon by Bgrowth^and Bpreferential attachment^ (Xie and Levinson 2009;Barabasi and Albert 1999).”
    Quote in the paperSubstantial claim1 of 2 sources checked
    • cites Xie and Levinson 2009 source
    • cites Barabasi and Albert 1999 source

  • May combine two claims.

    Findingown data

    Almost all visibility lines belonging to the artificial distribution are below the streets' visibility, with similar but much lower peaks around the street intersections.

    “In contrast to this, almost all the visibility lines belonging to the artificial distribution are below the streets' visibility, with similarbut much lowerpeaks around the street intersections (Fig. 7b).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The natural IVG's likely scale-free tail consists of nodes with degrees 18 to 66, while the artificial IVG's tail consists of nodes with degrees 12 to 31.

    “Comparing the two versions of IVG, we observe that the natural IVG likely scale-free tail consists of nodes with degrees 18 to 66, while the artificial one has degrees of 12 to 31.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    No distribution is successfully fitted with p-value >0.1; hence, the CSN method suggests rejecting the hypothesis that either distribution follows a power law.

    “No one of the distribution is successfully fitted with p-value >0.1.Hence, this method suggests that we should reject the hypothesis that either of our distribution follows power law.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    The artificial IVG has 5000 edges (available views), while the natural IVG has only 4172.

    “The artificial IVG has 5000 edges, i.e. available views, while the natural IVG has only 4172.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    R squared values of SNVG and artificial IVG show that these graphs exhibit an exponential distribution rather than a power law distribution, i.e. they are not scale-free.

    “R squared values of SNVG and artificial IVG show that these graphs exhibit an exponential distribution rather than a power law distribution, i.e. it is not scale-free.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    SNVG has a relatively heavier tail (39% of nodes) that is likely scale-free.

    “However, using this method we can see that SNVG has relatively heavier tail (39% of nodes) that is likely scale-free.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The average path length of the graphs is higher than that in the corresponding random graph, and significantly lower than in the corresponding regular graph.

    “Also the average path length of the graphs is higher than that in the corresponding random graph, and significantly lower than in the corresponding regular graph.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    All three graphs exhibit small-world properties; all S-statistics are higher than 1.

    “The results demonstrate that all three graphs exhibit small-world properties (Table 2).All S-statistics are higher than 1.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In the possible scale-free distribution of the natural IVG, most urban locations have the same low visibility, while only a few cafes and restaurants have extremely high level of visibility.

    “Examining behaviour of the 'third places' in the possible scale-free distribution of the natural IVG, we found that the most urban locations have the same low visibility, while only a few cafes and restaurants, have extremely high level of visibility.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Group A shows the tail of the degree distribution which is likely scale-free and includes the most visually connected places.

    “Group A shows the tail of the degree distribution which is likely scale-free and includes the most visually connected places.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The IVG pattern is not homogenous, but has a particular structure with many visually segregated locations, as well as a few locations with a large number of connections.

    “This pattern is not homogenous, but has a particular structure with many visually segregated locations, as well as a few locations with a large number of connections.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Group B includes places with a considerably smaller number of views and comprises the majority of locations (66%, 349 out of 526) with a degree less than 18.

    “While group B includes places with a considerably smaller number of views and comprised of the majority the locations (66%, 349 out of 526) with a degree less than 18.”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    Many other 'third places' are located on the same intersections as highly connected places from group A.

    “In Fig. 1b, which shows all the facilities in the area, it can be seen that there are many other 'third places' located on the same intersections.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Samples from group A have a high degree: A1 has 66 visual connections and A2 has 42, while both samples from group B (B1 and B2) have only 3 connections.

    “Samples from group A have a high degree: The first (A1) of 66 visual connections and the second (A2) of 42, while both samples from group B (B1 and B2) have only 3 connections.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Axial line graph represents a network of movement options by showing straight street segments drawn over every longest line of sight as nodes and their intersections as links.

    “A graph representation called axial line graph, represents a network of movement options by showing straight street segments drawn over every longest line of sight as nodes and their intersections as links (Hillier and Hanson 1984).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Hillier and Hanson 1984 source

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Characteristic point graph implements an alternative VG model that makes use of human navigational principles in the city; it is built of a set of navigational decision points, street intersections, as nodes in the graph.

    “Characteristic point graph implements an alternative VG model that makes use of the human navigational principles in the city; it is built of a set of navigational decision points, street intersections, as nodes in the graph (Jiang and Claramunt 2002).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Jiang and Claramunt 2002 source

  • May combine two claims.

    Premisecitation

    Visibility is an important determinant of urban vitality; visuospatial characteristics play a central role in navigation performance.

    “Visibility is an important determinant of urban vitality; visuospatial characteristics play a central role in navigation performance (Wang et al. 2014 for a review).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Wang et al. 2014 source

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    Some land uses, such as retail and entertainment places, tend to be distributed in a particular form, clustering together.

    “With that, it's known that some of the land uses, such as retail and entertainment places tend to be distributed in a particular form, clustering together (For instance, Fig. 1a).”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Real-world settings consist of a much wider range of physical properties of viewers and environments, including size, contrast, colour, shape, texture, pattern, complexity, static/dynamic position, atmospheric conditions, distance, angle of observation, etc.

    “Real-world settings consist of the much wider range of psychical properties of viewers and environments.These include size, contrast, colour, shape, texture, pattern, and complexity of the viewed elements, their static or dynamic position, atmospheric conditions, distance, angle of observation, etc. (Wang et al. 2014;Gret-Regamy et al. 2007;Shang and Bishop 2000).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Wang et al. 2014 source
    • cites Gret-Regamy et al. 2007 source
    • cites Shang and Bishop 2000 source

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductreasoning

    The main criterion for selection of food and drink facilities was availability of street seating places; this criterion ensures that the facilities behave as 'third places', i.e. places for urban social interactions.

    “The main criterion for their selection was availability of street seating places.This criterion ensures that the facilities behave as 'third places', i.e. places for urban social interactions.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    There has been a growing overlap between graph-based models and research of human spatial and visual cognition and navigation.

    “In recent years, there has been a strong degree of growing overlap between graph-based models and the research of human spatial and visual cognition and navigation (Natapov and Fisher-Gewirtzman 2016;Franz et al. 2005;Hölscher et al. 2006).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites Natapov and Fisher-Gewirtzman 2016 source
    • cites Franz et al. 2005
    • cites Hölscher et al. 2006 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Visibility graph (VG) represents space by imposing a regular or irregular grid on top of it.

    “Visibility graph (VG) represents space by imposing a regular or irregular grid on top of it (O' Sullivan and Turner 2001;Krüger 1979).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites O' Sullivan and Turner 2001

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Krüger 1979 source

  • Classified as probably not a substantial claim.

    Premisecitation

    Weisman (1981) describes a taxonomy of features for navigation, which include visual access between key locations, spatial differentiation, and layout complexity.

    “Weisman (1981) describes taxonomy of features for navigation, which include (a) visual access between key locations; (b) spatial differentiation and (c) layout complexity.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Weisman 1981 source

  • May combine two claims.

    Premisenone given

    Axial lines fail to differentiate between the centrality values of a particular location at the different ends of the street segment; all locations along a street corresponding to one sight line acquire identical centrality.

    “For instance, axial lines fail to differentiate between the centrality values of a particular location at the different ends of the street segment.All the locations along a street corresponding to one sight line acquire identical centrality.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    According to Bishop (2002), in areas with transparent skies, visibility modelling out to 20 km-30 km is justified.

    “However, according to Bishop (2002) in areas with transparent skies, visibility modelling out to 20 km-30 km is justified.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Bishop 2002 source

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Study design and conductnone given

    IVG represents urban environment in a very abstracted way.

    “In similarity to other graph techniques, IVG represents urban environment in a very abstracted way.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Premisecitation

    The emergence of urban uses and activities in cities is an inordinately complex process influenced by diverse zoning laws, de jure segregation and more.

    “The emergence of urban uses and activities in cities is inordinately complex process influenced by diverse zoning laws, de jure segregation and more (Loewenstein 1963).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Loewenstein 1963 source

  • May combine two claims.

    Premisecitation

    Visual properties are embedded in both the urban environment and pedestrian behaviour, and most pedestrian behaviours are guided by the processing of visuospatial information.

    “Visual properties are embedded in both the urban environment and pedestrian behaviour, and most pedestrian behaviours are guided by the processing of visuospatial information (Wiener et al. 2009;Golledge and Gärling 2002;Gibson 1950).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites Wiener et al. 2009

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Golledge and Gärling 2002

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

    • cites Gibson 1950

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Classified as probably not a substantial claim.

    Premisecitation

    The integrative visibility graph (IVG) used in this study encodes street network and building uses in one unified framework.

    “Integrative visibility graph (IVG) used in this study encodes street network and building uses in one unified framework (Natapov et al. 2013), (Fig. 2).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Natapov et al. 2013 source

  • May combine two claims.

    Premisecitation

    Streets tend to persist in time much longer than other urban elements like buildings or building uses, and provide a structural basis for further urban development.

    “Streets tend to persist in time much longer than other urban elements like ) b ( ) a ( buildings or building uses, and provide a structural basis for further urban development (Vernesz-Mouton, 1989).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Vernesz-Mouton, 1989

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationown data

    In non-geo-referenced layouts, central hubs of the graphs are clearly recognizable; these hubs identify urban locations with high visibility.

    “In such visualization, the central hubs of the graphs are clearly recognizable.These hubs identify urban locations with high visibility.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The natural IVG scale-free tail is longer than the artificial IVG's, and in these aspects the natural networks stay apart from the artificial one.

    “This means that the natural IVG scale-free tail is longer and in these aspects the natural networks stay apart from the artificial one.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Study design and conductnone given

    In dense urban conditions, the pure effect of the line of sight is the most influential, and other factors could be neglected.

    “In our case, when the method is applied to the dense urban conditions, pure effect of the line of sight is the most influential, and other factors could be neglected.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Since the early study of random graphs by Erdös and Renyi (1959), the degree distribution P(k) has become a common way of classifying graphs into categories.

    “Since the early study of random graphs performed by Erdös and Renyi (1959), the degree distribution”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Erdös and Renyi 1959 source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    Studies of street network representation have widely diverging results, depending on the representation procedures.

    “These studies have widely diverging results, depending on the representation procedures.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    The graph is suitable for other retail street-fronting urban facilities.

    “This study focuses on one specific sector of uses and activities ('third places'), however the graph is suitable for other retail street-fronting urban facilities.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Jiang and Claramunt (2004) reported that, under the street name approach, street graphs exhibit small-world characteristics but scale-free degree statistics can hardly be recognized.

    “However, it has been reported by Jiang and Claramunt (2004) that, under the street name approach, the street graphs exhibit small-world characteristics but scale-free degree statistics can hardly be recognized.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Jiang and Claramunt 2004

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    Carvalho and Penn (2010) studied the distribution of the length of open space linear segments, and showed that their cumulative distribution displays power-law tails.

    “Carvalho and Penn (2010) studied the distribution of the length of open space linear segments, and showed that their cumulative distribution displays power-law tails.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Carvalho and Penn 2010

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • May combine two claims.

    Interpretationreasoning

    The studied graphs are typified by many local interactions and by a smaller number of inter-area connections.

    “That means they are typified by many local interactions, and by a smaller number of inter-area connections.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Small-world graphs are classified according to two independent structural features, namely the average shortest path length and the clustering coefficient.

    “Small-world graphs are classified according to two independent structural features, namely the average shortest path length and the clustering coefficient (Watts and Strogatz 1998).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Watts and Strogatz 1998 source

  • Classified as probably not a substantial claim.

    Premisenone given

    Street networks can be converted into graphs using different methods of representations, such as nodes and edges corresponding to individual streets, street intersections, longest sights, street names or angularity.

    “As has already been mentioned, street networks can be converted into graphs using different methods of representations, such as nodes and edges corresponding to individual streets, street intersections, longest sights, street names or angularity.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    The comparison between the original network of activities and the artificially uniform layout enabled assessment of potential links between visibility and urban morphology in a weighed and controlled manner.

    “In applying our analyses both to the original network of activities and to the layout resulting from the procedure described above, we created a comparison that enabled us to assess potential links between visibility and urban morphology in a weighed and controlled manner.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    In studies of street networks, various results of degree statistics can be found.

    “In studies of street networks, various results of degree statistics can be found.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Jiang (2006) showed that topographic surfaces exhibit an exponential distribution rather than a power law, i.e. it is not scale-free, in contrast to many other real world networks.

    “With regard to other visibility graphs, Jiang (2006) showed that topographic surfaces exhibit an exponential distribution rather than a power law, i.e. it is not scale-free, in contrast to many other real world networks.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Jiang 2006

      Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationown data

    The fact that these networks are small-world opens a new direction in network research.

    “The fact that these networks are small-world opens a new direction in network research.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisenone given

    The possibility of breaking a graph into two separated graphs, SNVG and IVG, allows using both street networks and building uses as units of analysis, and computing network measures separately for each of them.

    “The possibility of breaking a graph into two separated graphs, SNVG and IVG, allow us to use both street networks and building uses as units of the analysis, and to compute network measures separately for each of them.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    The natural IVG distribution fits best the description that most locations have approximately the same low level of visibility, while only a few intersections and urban activity locations have extremely high levels of visibility, which usually designates the scale-free property.

    “we see that the natural IVG distribution fits the best the description Bthe most locations have approximately the same low level of visibility, while only a few intersections and urban activity locations have extremely high levels of visibility^which is usually designates the scale-free property.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationreasoning

    Sharing statistical and morphological similarities with many complex systems suggests that common organizational principles might underlie these processes.

    “Sharing statistical and morphological similarities with many complex systemsincluding food chains, metabolite processing networks, networks of brain neurons, voter networks, telephone call graphs and social networks, suggests that common organizational principles might underlie these processes.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisereasoning

    In general, street networks do not provide sufficient data to draw conclusions about the universality of degree statistics.

    “In general, street networks do not provide sufficient data to draw conclusions about the universality of degree statistics.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Diverse visuospatial attributes, such as viewpoints or vistas, have considerable economic significance and value.

    “It's known that diverse visuospatial attributes, such as viewpoints or vistas, have considerable economic significance and value (Lang and Schaffer 2001).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites Lang and Schaffer 2001 source

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Premisecitation

    Network approach allows us to study the city as a formal emergent phenomenon, with a 'hidden hand' guiding its growth, and no top-down decision-maker guiding its physical and spatial organization.

    “Network approach allows us to study the city as a formal emergent phenomenon, with a Bhidden hand^guiding its growth, and no top-down decision-maker guiding its physical and spatial organization (Batty 2013;Batty 2003).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites Batty 2013 source
    • cites Batty 2003

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationreasoning

    This study sets a framework for an evidence-based design tool to assist planners in the evaluation of urban projects in the rapidly urbanizing world.

    “Therefore this study sets a framework for an evidence-based design tool to assist planners in the evaluation of urban projects in the rapidly urbanizing world.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: City performance depends on the allocation of urban uses and activities.

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    Observed network properties have important implications in terms of spatial modelling, and can assist researchers in understanding the mechanisms that underlie the emergence of urban activities.

    “Therefore, observed network properties have important implications in terms of spatial modelling, and can assist researchers in understanding the mechanisms that underlie the emergence of urban activities.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Space in the less connected locations (B1 and B2) is more controlled and small in size; thus, distant views are blocked.

    “Space in the less connected locations (B1 and B2) is more controlled and small in size; thus, distant views are blocked.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationreasoning

    Our findings suggest the utility of relating urban dynamics to complex network theory, creating a new link between behavioural and spatial processes in cities.

    “Furthermore, our findings suggest the utility of relating urban dynamics to complex network theory, creating a new link between behavioural and spatial processes in cities.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The tests are performed only on the three cases: street network, natural distribution of uses and artificial distribution of uses.

    “Second, the tests are performed only on the three cases: street network, natural distribution of uses and artificial distribution of uses.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Jones et al. (2008) introduced a concept of 'Link and Place' to analyse streets on a basis of the needs of people, rather than vehicles.

    “Jones et al. (2008) introduced a concept of BLink and Place^to analyse streets on a basis of the needs of people, rather than vehicles.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites Jones et al. (2008) source

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    The IVG in its current form is limited to two-dimensional representation that ignores additional factors affecting visual perception.

    “First, the IVG in its current form is limited to two-dimensional representation that ignores additional factors affecting visual perception.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    There is still not enough data to draw comprehensive conclusions about the universality of streets' degree statistics across the various street representation and analysis methods.

    “However, there is still not enough data to draw comprehensive conclusions about the universality of streets' degree statistics across the various street representation and analysis methods.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The IVG representation allows combining 'Link and Place' concepts in one graph-based method and examining street connectivity together with consideration of functional locations.

    “Therefore it allows to combine BLink and Place^concepts in one graph-based method and to examine street connectivity together with consideration of functional locations, hence presenting more comprehensive picture of urban realm.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    The IVG heterogeneous pattern represents the number of views faced by a traveller in the real environment.

    “IVG heterogeneous pattern represents the number of views faced by a traveller in the real environment.”
    Quote in the paperNot a substantial claim
70 of 70

  • The paper relies on this without support.

    Performance of a range of urban amenities is influenced by their accessibility to pedestrians.

    “Performance of a range of urban amenities is influenced by their accessibility to pedestrians.”

  • The paper relies on this without support.

    Walkability in cities varies depending on the specific morphology of street network, distribution of urban locations and availability of visual information.

    “Walkability in cities varies, depending on the specific morphology of street network, distribution of urban locations and the availability of visual information.”

  • The paper relies on this without support.

    Urban uses and activities are important features of the city landscape, serving as origin and destination points for traveller routes and accommodative centres of urban life.

    “They serve as origin and destination points for traveller routes, and are accommodative centres of urban life.”

  • The paper relies on this without support.

    On the fine-grained resolution, the exact location of new openings in buildings is a spontaneous, bottom-up urban phenomenon, not prescribed by planning authorities.

    “However, on the fine-grained resolution, the exact location of new openings in buildings is a spontaneous, bottom-up urban phenomenon, not prescribed by planning authorities.”

  • The paper relies on this without support.

    The moderate Israeli climate and street-oriented frontages of historical buildings make the district an ideal location for all kinds of 'third places'.

    “The moderate Israeli climate, and the streetoriented frontages of historical buildings make the district an ideal location for all kinds of 'third places'.”

  • The paper relies on this without support.

    The profitability of food and drink places is a function of visit frequency, since they are amongst the most probable navigation targets for tourists and local pedestrians strolling through the area.

    “The profitability of these places is a function of visit frequency, since they are amongst the most probable navigation targets for tourists and local pedestrians strolling through the area.”

  • The paper relies on this without support.

    Neither accounting for a particular location such as building use throughout the visibility network nor using both street networks and building uses as units of analysis is addressed in most urban graph methods.

    “Neither of these is addressed in most urban graph methods.”

  • The paper relies on this without support.

    City performance depends on the allocation of urban uses and activities.

    “city performance depends on the allocation of urban uses and activities”

  • The paper relies on this without support.

    The exact locations of cafés and restaurants are not designed by planning authorities, but are the result of bottom-up processes intrinsic to the way cities grow and evolve.

    “Typically, the exact locations of cafés and restaurants are not designed by planning authorities, but are the result of bottom-up processes, intrinsic to the way cities grow and evolve.”
9 of 9

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Natural and artificial tail thresholds are reversed

    Major

    The text assigns the natural IVG a tail beginning at degree 18 and the artificial IVG one beginning at degree 12. Table 3 gives xMin as 12 for the natural IVG and 18 for the artificial IVG.

1 of 1

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Authors
Natapov, A., Czamanski, D., & Fisher-Gewirtzman, D.
Affiliations
  • University College London (GB)
  • Western Galilee College (IL)
  • Technion – Israel Institute of Technology (IL)
Corresponding author
Natapov, Asya
ORCID
Venue
Networks and Spatial Economics
Publisher
Springer Science and Business Media LLC
Published
2018-07-07
Volume
18
Issue
3
Pages
555-575
ISSN
  • 1566-113X (ISSN-L)
  • 1572-9427
DOI
10.1007/s11067-018-9411-4
OpenAlex
W2821472895
Cited by
11
References
50
Citations by year
2026: 3 · 2025: 1 · 2024: 1 · 2023: 1 · 2021: 2 · 2020: 1 · 2019: 1 · 2018: 1
FWCI
0.98
Type
journal article
Language
en
Open access
Licence
Locations
  • Networks and Spatial Economics (publishedVersion, cc-by)
  • RePEc: Research Papers in Economics (submittedVersion)
  • UCL Discovery (University College London) (submittedVersion)
Funders
  • Israel Science Foundation (59/17)
  • Joan and Reginald Coleman-Cohen Fund
Topics
  • Physical Sciences › Engineering › Building and Construction › Urban Design and Spatial Analysis
  • Physical Sciences › Physics and Astronomy › Statistical and Nonlinear Physics › Complex Network Analysis Techniques
  • Social Sciences › Transportation › Urban Transport and Accessibility
Keywords
visibility graph, street networks, pedestrian accessibility, urban amenities, small-world networks, scale-free networks, network hubs, visual cognition, network structure

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-21.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-21.

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