Plant Screens Differentiate the Perception of Safety and Privacy and Thus Influence Preferences and Willingness to Spend Time in the Park Space

Abstract

Urban park areas mitigate urbanization’s negative impacts by integrating environmental, social and cultural benefits. Development strategies should enable participation and consider all user groups’ needs, following sustainability principles. However, ensuring multifunctionality often generates conflicting decisions. While the universal necessity for safety is widely acknowledged, its implementation frequently results in the diminution of a crucial sense of privacy. For example, the universally recognized need for safety may compromise the willingness sense of privacy or intimacy. This can discourage those for whom this need is important and prevent urban parks from fully utilizing their social potential. This study examines how spatial configurations of plant forms within urban parks shape personal experiences. We used an intra-group design to evaluate photographs of park spaces, manipulated using Photoshop AI algorithms to examine safety, privacy, preference, and willingness to spend time. Variables included space size and shape. The study used Computer-Assisted Web Interviewing (CAWI) with 300 participants. Regression and mediation analyses showed willingness to visit derives from space attractiveness, influenced by perceived safety and privacy. Analyses revealed the following: open areas were safest but the least private, corridor spaces were the least safe but the most private; curtain screens enhanced perception better than corridor screens; small spaces with corridor screens were least attractive; space size mattered less for open spaces than screened spaces; and spatial configuration was critical in assessing small spaces. The findings of this research enhance our comprehension of the perception of park spaces. They hold potential practical implications for sustainable design, facilitating the development of plant forms that are more socially effective, particularly those with substantial environmental value, such as dense vegetation that serves as visual screens. Neglecting these preferences may result in inappropriate design decisions that fail to accommodate users’ needs and behaviors, thereby not fully capitalizing on the potential of urban green spaces.

1. Introduction

1.1. Research Framework

Urban park areas, providing key ecosystem services within the environmental domain and implementing social and cultural programs integrate benefits, shaping a multidimensional potential to mitigate the negative impact of urbanization on urban communities [1,2,3]. Research indicates that living in proximity to urban green space generally encourages increased physical activity, positive health behaviors and improved health outcomes, highlighting the comprehensive impact of nature on both mental and physical health indicators [4,5,6,7]. The opportunity for interaction with nature is considered a fundamental paradigm for the sustainability of urban areas and agglomerations [8,9,10]. According to current guidelines on accessibility and environmental justice [11,12], park spaces that facilitate recreation, relaxation, and community development should align with the diverse perspectives and expectations of different users. However, the growing and increasingly diverse urban population necessitates careful identification of users’ needs to effectively program the health and well-being potential of such spaces. The anticipated multifunctionality often results in mutually exclusive decision-making. A significant factor contributing to these limitations is the universally acknowledged requirement for safety.

Despite widespread acceptance, the integration of safety considerations into park design strategies often results in contentious decisions that may conflict with the need for privacy or intimacy associated with recreation in urban green spaces. Currently, we have substantial knowledge regarding the impact of park design on the perception of safety. However, principles advocating for the limitation of plants as visual screens [13,14,15], which are promoted based on this understanding, may not be optimal from the perspective of the environmental efficacy of green spaces.

Achieving a sustainable environment necessitates the implementation of solutions that offer a wide range of benefits for users and require a careful balance between them. A primary expectation of green spaces is the enhancement of environmental conditions, including mitigating the effects of urban heat islands (UHI) [16,17,18,19]. Urban thermal strategies, predominantly reliant on the implementation of well-designed biologically active nature-based solutions (NBSs), leverage the capacity of vegetation to regulate radiation balance [20], modify shaded areas, direct and obstruct airflow, alter the aerodynamic roughness [21], and induce a cooling effect by activating physiological processes [20,22]. Analyses of the thermal efficiency of various plant configurations reveal the high efficacy of communities with diverse horizontal and vertical profiles, underscoring the significance of communities with an extensive mid-canopy and substantial presence of shrubs [20,23,24]. Quantifying the cooling effects underscores the importance of shrub vegetation in local-scale thermal strategies [17,18].

Beyond environmental considerations, as we demonstrate later in this article, the use of plant groups as screens is vital for fulfilling the need for privacy and intimacy in parks. This, in turn, can significantly influence the utilization of these spaces, thereby ensuring maximum societal benefit from ecosystem services. Paradoxically, the constraints imposed by safety considerations may be particularly pronounced for social groups most vulnerable to threats (e.g., women and the elderly) [25], who require safe spaces and simultaneously seek refuge from excessive urban stimuli. Failure to acknowledge these needs may, on one hand, result in a diminished sense of safety and, on the other, may not fulfill the expectation of intimacy, thereby hindering the full realization of the social potential of urban parks.

Meanwhile, well-organized park space, conducive to spending time, can significantly improve the quality of life and health of conurbation residents [26,27,28]. Based on this assumption, we decided to conduct research aimed at identifying the impact of selected park features and the feelings they evoke on the willingness to spend time there. The research plan addressed research gaps, including a lack of consensus and insufficient evidence for certain relationships (Figure 1). The current state of knowledge is presented in detail in this paper.

Studies on residents’ feelings towards park spaces tend to focus on their preferences for park landscapes, assuming that they will translate into the willingness to spend time in the park. Indeed, a number of studies have indicated that parks assessed as attractive are popular places to visit [29,30], but it is worth confirming whether the attractiveness of a park impacts people’s willingness to spend time there.

Of all the predictors of preferences for park spaces, one of the most frequently studied is a sense of safety [31,32,33,34,35,36]. Far fewer studies have considered another important need—privacy, which is one of the motivators for seeking spaces in parks that are conducive to intimacy or spending time alone, without the feeling of being watched by other visitors [37,38,39,40]. However, the relationship between the theoretical constructs of safety and privacy remains ambiguous. Privacy, characterized by invisibility in space (beyond visual control), may enhance a sense of safety by allowing individuals to remain unnoticed by potential threats, as suggested by the shelter phenomenon in Appleton’s prospect-refuge theory [41]. Conversely, invisibility can also diminish the extent of social oversight, rendering both perilous situations and opportunities for assistance equally imperceptible [42,43,44]. This issue is explored in greater detail below. Consequently, it can be inferred that these constructs share a common element, namely, that invisibility can provide a sense of safety, while also possessing distinct elements that operate in opposition, where the absence of social connection can lead to feelings of isolation. Irrespective of the theoretical linkage between safety and privacy, prior research indicates that these needs are fulfilled in different spatial environments. Furthermore, privacy-friendly spaces are usually characterized by less safety, and vice versa—the safest spaces tend not to be sufficiently private [38,39,40]. Due to (1) the importance of meeting each of these needs within urban parks, and (2) the complex and ambiguous nature of the relationship between privacy and safety, we concluded that when examining the impact of park spatial characteristics on the willingness to spend time there, both variables should be considered simultaneously. To gain deeper insight into visitors’ feelings in this regard, we decided to examine whether (1) the ability to meet privacy and safety needs leads to a greater willingness to spend time there, and whether (2) this is due to the attractiveness of spaces that provide a sense of privacy and safety. This verification was the first goal of this study (Figure 1).

To identify research gaps and define the purpose of the study, we analyzed scientific articles in the field of environmental psychology, addressing the impact of park space characteristics on two variables: sense of safety and privacy. We considered articles based on measurable (not speculative) research findings that identified the relationships between these variables (e.g., correlation and regression analyses, including mediation models). Such studies are relatively few and focus solely on certain spatial features, such as visual and physical accessibility [38,39], amount and density of vegetation [40,44] distance from other park visitors [39,45], number of visitors [45] and how the park is lit [46]. One of the most important elements influencing a sense of safety and privacy is viewing screens—spatial forms (usually plant-based in parks) that limit contact with the surroundings. For simplicity, we refer to these forms as screens in this article (other terms such as visual barriers also appear in the literature). Although the general finding has been that viewing screens reduce safety and increase privacy [38,39], the influence of the spatial form of these screens on these variables has not been studied. It can be assumed that curtain screens (screens placed across the communication route we are following or across the leading viewline) evoke different sensations than corridor screens (screens placed along the communication route or leading view line). The former obscures distant views but allows for a wide view of the immediate surroundings. These can be compact groups of greenery that form a wall enclosing a landscape interi3or. The latter allows for the observation of paths or viewing axes, but limits the view of the surrounding landscape. These can be rows of greenery placed along paths in the form of espaliers or hedges. It is also possible that these sensations vary depending on the size of the space, and consequently, the distance of the screens from the visitor (Figure 2).

The size of landscape interiors and their spatial features, which create various visual connections, are among the basic spatial characteristics of parks. Therefore, understanding how these factors impact visitors’ feelings and, consequently, their willingness to spend time in parks would seem to be particularly relevant to the conscious design of urban parks. The second objective of this study was to examine this impact (Figure 1).

This study was developed based on the following plan. Research gaps and objectives were identified (Figure 1). Next, a theoretical framework was established, encompassing three perspectives in particular, which served as the basis for defining the research criteria, directions, and research hypotheses (Figure 2). Next, we tested the research hypotheses corresponding to the stated objectives through participant assessments using a carefully designed questionnaire. The assessment results were subjected to statistical analyses and presented in tabular and graphical (synthetic) formats. Finally, an interpretation of the results and conclusions is presented.

This research, in its subject matter and methods, is grounded in environmental psychology. However, the stated objectives and results allow us to consider the acquired knowledge as useful in areas dealing with the development of urban green spaces. It outlines a framework based on the recognition of the mechanisms of human perception for designing green infrastructure in accordance with the principles of sustainable development.

1.2. The Theoretical Basis

Environmental psychology features a well-established theoretical framework that facilitates the understanding and prediction of the impact of various spatial forms on the sense of safety, privacy, and preference. The basic perspective, applied particularly in research on sense of safety/danger, is Appleton’s prospect-refuge theory [41], which goes back to human biological roots, assuming that the most attractive (preferred) spaces are those that facilitate survival. In the context of this theory, these spaces may be understood as those that are close enough to provide refuge where one might remain unnoticed by a potential attacker and open enough to offer an opportunity to observe the surroundings and notice approaching danger in time. This theory has served as a starting point for studying park features that affect a sense of danger/safety [47,48]. However, in practice, it has encountered a major problem: a double understanding of hideouts. This was pointed out by Fisher and Nasar [31], among others, who noted that spatial forms that can constitute a hideout from the enemy (as in Appleton’s theory) can simultaneously constitute a hideout for a potential attacker, and thus exacerbate a sense of threat. Many studies have shown that the existence of places that offer concealment is a strong predictor of threats to people [49,50,51,52]. Taking into account the fact that hiding places can also offer a sense of privacy—including intimacy if so willingness—the problem becomes even more complex, and without taking into account this complexity, it is impossible to state whether places conducive to hiding are liked.

Another theoretical perspective relevant to establishing links between viewing screens in public spaces (including city parks) and people’s feelings is social control, which is a key element of safe spaces. The conditions for their existence are visibility linked to the form of space, enabling observation, noticing danger, and reacting. This perspective has been used to support numerous studies including social control, and several studies have considered strategies for designing safe spaces [13,53,54].

Researchers have long acknowledged that one of the basic factors influencing the safety of a space is informal control, meaning that a random observer may notice and react to a dangerous situation [42,43]. Although notions regarding such spaces vary, their essence, the existence of social control, remains the same. Strategies for designing safe spaces also apply this principle [55,56,57]. In order for social control to exist and be effective, not only are ‘observers’ required, but also appropriate spatial conditions offering good visibility. From this perspective, areas that are visible, open, and free from viewing screens are considered safer. However, this feature may negatively affect perceived privacy, defined as limited social control [58,59]. Therefore, this perspective does not clarify whether visible places with a clear view are more attractive than those with obscured views.

Finally, a perspective that may not directly relate to a sense of threat or privacy, but one that has made a well-established contribution to understanding landscape preferences, is the Kaplan Preference Matrix [60,61] (especially the part that refers to 3D factors. The matrix of the four ‘informational variables’ influencing landscape preferences involved in this theory is of two types: factors operating in 2D space (coherence and complexity) and factors operating in 3D space (legibility and mystery). The latter is particularly dependent on form and shape. Legibility affects how space is understood, helping us build mental maps in our minds [61,62], orient ourselves, and find our way back. This, in turn, has a significant impact on the sense of safety [46] inter alia, because it facilitates escape in the event of danger. Numerous studies on space legibility link it to openness and visibility [62,63,64], indicating that a lack of visual barriers has a positive effect on the sense of safety and, therefore, on preference [65]. Mystery, the second of the 3D factors from the Kaplan Preference Matrix, works differently in that it stimulates curiosity and, as a result, encourages exploration [66,67]. It also plays a biological role because exploration provides information about an area and all related situational circumstances necessary for survival. However, the factors influencing mystery are completely different, sometimes even opposite, to those that make a place legible. Mystery is positively correlated with barriers and viewing screens [63,64,65,68,69] because they obscure what is coming up next and make us want to proceed further into the landscape to satisfy our curiosity. Mysterious landscapes are attractive, although, in some circumstances, they may be less safe [70]. As we can see, the perspective of the Kaplan Preference Matrix does not clearly answer the question of whether viewing screens are liked.

The perspectives outlined above illustrate the complexity of the problem studied here, as well as the need to explore it further.

1.3. Spatial Configurations of Park Interiors—Impact on the Feelings Studied Here

Multiple studies have shown that the spatial configuration and physical features of the environment can affect perceptions of fear and danger and the sense of privacy [38,39,40,71,72] (isolated and less-frequented park areas that may potentially provide spaces for intimacy or solitude are often perceived as dangerous). These areas lack natural supervision—the presence of other people who might act as deterrents to people who pose a potential threat [73,74]. There is no chance of surveying the surroundings beyond viewing screens, and at the same time, plant forms can provide a cover for potential attackers. This means that spatially enclosed places are often associated with perceived threats [32,33,75]. This, in turn, may have a negative impact on how such spaces are evaluated and on the willingness to spend time there. Closed places in parks surrounded by plant barriers may also evoke a sense of uncertainty and threat, thus curbing the regenerative experiences of nature [33,76].

However, partitions enhance acoustic and visual comfort by creating the impression that one is cut off from the influence of harmful external stimuli. Environments with higher visual and acoustic comfort are associated with positive emotions such as joy and relaxation, which may raise the perception of intimacy, and vice versa—environments that cause visual and acoustic discomfort can evoke negative psychological states, potentially undermining perceptions of intimacy [77]. Therefore, spaces surrounded by plant barriers that provide sensory separation from their surroundings present tremendous restorative potential [78]. Studies have indicated that people attribute a higher restorative potential to enclosed spaces surrounded by trees and shrubs in landscaped interiors [79,80], which can be experienced as a refuge or sanctuary [78].

Clearly, the influence of plant barriers on human feelings is unclear. Additionally, the spatial arrangement of greenery can affect these sensations, both individually and interactively [32,33]. For example, dense vegetation more strongly undermines perceived safety when trees are located on either side of a path compared to when they grow only on one side [33]. This implies that the influence of spatial configuration on human sensation is not straightforward. Boiling down the impact of plant visual barriers to two alternatives, closed or open, seems too superficial for a true grasp of the issue. However, this requires further research and analysis. The emotional impact of these barriers is complex and varies according to the specific design and context of the park [81]. It seems that the combination of screen orientation and size of the visual openings provides a fairly wide range of typical spatial situations. Therefore, these factors were chosen as the basic independent variables in this study.

The theoretical foundations presented in the previous section also suggest that the relationships between the feelings that influence preference and willingness to spend time in a park (privacy and sense of safety) are still ambiguous. The sense of safety has a significant, often crucial, impact on preference, assuming that our preferences are determined by how a particular space may be conducive to survival. Following this line of thought, one may think that safe environments are always preferred as places for recreation. Moreover, perceived safety has been demonstrated to mediate the relationship between spatial barriers and regeneration, which is an important reason why people may want to spend time in a park [82,83]. This suggests that environments perceived as safe are more regenerative and potentially more conducive to intimate interactions and seclusion (privacy). In general, many studies have shown that a sense of safety is an important mediator of positive feelings, such as preference [39] or the ability to regenerate, as well as restore focus and mood [75]. Yet, at the same time, other research has revealed that the positive effect of safe spaces on preference is inhibited by the reduced privacy [39,40] or mystery [70] (that accompanies these spaces. In extreme cases, opposing actions of safety and privacy (or mystery) may significantly undermine or even destroy the positive influence of a sense of safety on preference [38].

These findings make it even more difficult to analyze and determine the impact of viewing screens on the sense of safety and privacy, as well as on preference and willingness to spend time in a given area. Indeed, finding the ‘ideal’ configuration may prove to be an impossible task; certain configurations evoke some positive feelings while reducing others (Figure 2). Therefore, understanding the impact of spatial forms on visitors’ feelings, and then consciously using this knowledge, requires examining several key variables simultaneously in certain models and research plans. In this study, four variables were selected for testing, the relationships between which are still ambiguous and not sufficiently understood: privacy, sense of safety, preference, and willingness to spend time in a given space.

1.4. Research Hypotheses

Considering the above considerations and theoretical analyses, the following research hypotheses were formulated.

H1: 

Willingness to visit a park area stems from an assessment of how attractive the space is (preference), which is affected by a sense of safety and the extent to which the space satisfies the need for privacy;

H2: 

Sense of safety, privacy, preference towards park space, and willingness to spend time are influenced by the size of the landscape interior and the types of spatial barriers featured therein.

2. Materials and Methods

2.1. Study Design

The study employed a survey methodology wherein participants evaluated park spaces depicted in strategically manipulated photographs. The research was predicated on an intragroup experimental design, with spatial features serving as predictors and participants’ emotional responses as dependent variables. The studied variables and measurement methods are presented in

Table 1. Study Variables and Their Measurement Method.

Predictors	Categories (Configurations) Created by Visual Manipulation
Size of the space (screen distance)	Large (distant screens)	Mixed (some screens close, some distant)	Small (screens close)
Shape of the space (screen type)	None (Open space)	Lateral screens (curtains)	Longitudinal screens (corridor)
Dependent variables	Operational definition (survey question)		Assessment method
Privacy	Rate to what extent the place where the photo was taken may satisfy your need for privacy. Answer on a scale from 1 to 5, where 1 = not at all, and 5 = very much		- comparison of mean ratings (ANOVA with repeated measures)—H2
Sense of safety	Rate how safe or unsafe you would feel in the place where the photo was taken. Answer on a scale from 1 to 5, where 1 = very unsafe and 5 = very safe		- comparison of mean ratings (ANOVA with repeated measures)—H2
Preference	How much do you like the setting? This is your own personal preference for the setting, so please do not worry about whether you are right or wrong or whether you agree with someone else. Answer on a scale from 1 to 5, where 1 = not at all and 5 = very much		- comparison of mean ratings (ANOVA with repeated measures)—H2 - regression analysis with a model taking into account the impact of privacy and safety on preferences
Willingness to spend time there	Please rate your willingness to spend time in the location shown in the photograph. Respond using a scale from 1 to 5, where 1 indicates “not at all” and 5 signifies “very much”		- comparison of mean ratings (ANOVA with repeated measures)—H2 - mediation analysis with a model where the predictors are sense of safety and privacy and the mediator is preferences—H1

.

Participants assessed the photographs based on four criteria: sense of safety, sense of privacy, preference for the park landscape, and willingness to spend time in the area. The manipulation of predictors was grounded in two photographs of park spaces: one illustrating an open clearing and the other depicting a tree-lined park area. Both photographs depict a pathway, introduced to guide the primary viewing axis, thereby determining the orientation of the screens (either perpendicular or parallel to the path/viewing axis). Additionally, the presence of the pathway distinctly signifies the nature of the space being depicted—it is a park space, as opposed to, for instance, undeveloped green areas. These photographs were altered to create nine scenarios based on specific factors (Figure 3). The first factor was the size of the space, categorized into three options: large, small, or mixed (i.e., a space offering a combination of proximate and distant views). The second factor pertained to the shape of the space, with three configurations: open (without viewing screens), lateral screens (curtains), and longitudinal screens (corridors). The screens were positioned at varying distances from the path, contingent on the size of the space factor. In small spaces, the screens were situated near the path, thereby narrowing the field of view. Conversely, in large spaces, the screens were placed further from the path, allowing for open space along it. Mixed spaces exhibited some asymmetry. The outcomes of the manipulations for both photographs (space without trees and space with trees) are illustrated in Figure 4 and Figure 5.

2.2. Research Instrument (Questionnaire)

The manipulation of photographs was conducted using Adobe Photoshop functions that utilize artificial intelligence algorithms, specifically ‘generative fill’ and ‘generate.’ The spatial dimensions were altered by either removing or adding greenery, predominantly trees, to the foreground or background. Additionally, lateral (curtain) and longitudinal (corridor) screens were constructed by strategically adding shrubs in specific configurations. During the process of modifying the photographs, we ensured that the introduced plant forms did not significantly deviate in terms of factors not subject to modification. We posited that the plants constituting the screens (the manipulation factor) would exhibit a natural (unshaped) growth habit and would lack ornamental flowers, colorful foliage, or unusual growth patterns. This approach was intended to minimize the potential influence of uncontrolled variables. Based on this premise, an appropriate generation process was implemented. Initially, we identified locations where new plant forms were introduced. This location is contingent on the nature of the created scenery. For instance, in the case of corridor screens, the designated area is along the path, whereas for transverse screens, it is across the path. Subsequently, we formulated directives such as “shrub,” “tree,” or “shrub group.” If the resulting generation did not conform to the aforementioned conditions (i.e., the plants were excessively distinct or contained distinctive elements), the generation process was repeated until a satisfactory outcome was achieved. In instances where difficulties arose in achieving this result, the image was modified through additional actions such as altering the height or width of the plant forms by intelligently removing or adding appropriate image fragments. Such modifications necessitated manual intervention as fully automated modifications would have contravened the established study rigor. Notably, the artificial intelligence algorithm incorporates functions that facilitate the automatic adjustment of factors related to the realism of the scene, ensuring consistent lighting conditions (including shadow directions), colors, and contrasts during manipulation.

The questionnaire was structured as follows: A set of 18 photographs (2 × 3 × 3), generated through manipulation, was arranged in a random sequence. Initially, respondents were presented with the entire set of photographs that they were required to evaluate. This approach enabled participants to establish a subjective scale for subsequent assessments. Subsequently, participants were instructed to evaluate all the photographs based on one variable, followed by evaluations for a second variable, and so forth. The sequence of the questions (variables evaluated) was randomly generated for each participant.

The variables were rated on a 5-point Likert scale, with 1 being the lowest score and 5 being the highest. This scale is commonly used to measure participants’ feelings towards landscapes [47,63,64,69,70].

Questions pertaining to safety, privacy, and preference were developed based on established operational definitions [39,62,63,70]. The wording of these questions is presented in Table 1.

2.3. Participants

The survey was administered through an online questionnaire utilizing the CAWI (computer-assisted web interviews) method, conducted by an external company that recruited participants from its registered database of respondents. Participation in the study was entirely voluntary, and all participants retained the right to withdraw from the study at any stage.

The study was conducted using a research panel that included a broad group of adult Polish residents (approximately 200,000) who expressed an interest in regularly participating in online opinion, marketing, and social research. The panel is nationwide, and its demographic structure is constantly monitored and compared with data from the Central Statistical Office, enabling the selection of samples that are representative of the adult Polish population.

Consistent with previous research [52,68,69,70], our study incorporated questions pertaining to gender and age, in addition to inquiries about photo ratings. These basic sociodemographic variables have been shown to influence the variables under investigation, particularly the sense of safety and privacy. Gender was accounted for through proportional sampling (50% male and 50% female), and age was included in the question.

The study sample consisted of 300 participants (150 men and women). The invitations were sent to randomly selected groups of respondents, but with a number 10 times larger than the expected sample in each assumed quotation element.

The response rate was 64.5%. The survey was completed by 300 participants (age range = 19–77 years; M_age = 42.23; SD_age = 11.49).

All procedures were performed in compliance with relevant laws and institutional guidelines.

3. Results

3.1. Assumptions

Statistical analyses were conducted utilizing JAMOVI version 2.2.5, with the significance threshold established at α = 0.05. Regression and mediation effects were examined through the GML Mediation Model module, where the statistical significance of mediation effects was determined using 95% confidence intervals derived from the bootstrap method with n = 5000 samples, alongside the Sobel test. Additionally, a series of repeated-measures analyses of variance (ANOVA) was performed. The significance of the main and interaction effects, as well as the post-hoc tests, was assessed using 95% confidence intervals.

The results section contained no missing data.

Prior to conducting the analyses, the fundamental assumptions for regression analyses and repeated-measures analysis of variance (ANOVA) were evaluated. Descriptive statistics were employed to verify the assumption of normality of the distribution, along with the Shapiro-Wilk test, which produced significant results in all scenarios. However, the skewness and kurtosis values, each with an absolute value of less than 2 [84], suggest that the distributions do not significantly deviate from normality. Additionally, in relation to the planned repeated-measures ANOVA analyses, tests of sphericity (Mauchly’s W) were conducted.

For those effects where the sphericity assumption was violated, the Greenhouse–Geisser correction was applied.

The study investigated the impact of sex and age on the analytical outcomes. The findings indicated that age did not significantly influence the results; however, sex was found to have a notable effect on the safety assessment, with women rating it significantly lower than men.

3.2. Results of Testing Hypothesis H1

To test H1, a multiple regression analysis was initially performed to check whether a sense of privacy and safety were predictors of preference. The model controlled for the age and gender of the participants. Both predictors turned out to be significant, and the model turned out to be a good fit, explaining 32% of the variance (Appendix A).

Next, the influence of preferences on the relationship between privacy and safety and the willingness to spend time in a given place was examined. The mediation analysis (

Table 2. Mediation analysis where the relationship between privacy and safety and the willingness to spend time in the location the space is mediated by preference—Indirect and Total Effects.

Indirect and Total Effects
				95% C.I. (a)
Type	Effect	Estimate	SE	Lower	Upper	β	z	p
Indirect	Safety ⇒ Preference ⇒ Willingness	0.3	0.06	0.18	0.41	0.29	4.91	<0.001
	Privacy ⇒ Preference ⇒ Willingness	0.24	0.06	0.13	0.36	0.25	4.12	<0.001
Component	Safety ⇒ Preference	0.33	0.06	0.21	0.45	0.37	5.21	<0.001
	Preference ⇒ Willingness	0.89	0.06	0.75	1	0.8	14.3	<0.001
	Privacy ⇒ Preference	0.27	0.06	0.15	0.39	0.31	4.36	<0.001
Direct	Safety ⇒ Willingness	0	0.04	−0.08	0.08	0	−0.11	0.909
	Privacy ⇒ Willingness	0.09	0.05	0	0.18	0.09	1.88	0.06
Total	Safety ⇒ Willingness	0.29	0.07	0.15	0.43	0.29	4	<0.001
	Privacy ⇒ Willingness	0.33	0.06	0.21	0.45	0.34	5.29	<0.001

Note. Confidence intervals computed according to the Bootstrap percentiles method. Betas are completely standardised effect sizes.

, Figure 6) showed that preference was a mediator for both. After introducing it, the relationship between privacy and willingness to spend time in an area and between safety and this willingness becomes statistically insignificant. Both mediation effects are statistically significant, as indicated by both the Z-test result (p < 0.001) and the bootstrap confidence interval not containing 0 in its interval.

3.3. Results of Testing Hypothesis H2

To test hypothesis H2, ANOVA analyses of variance were successively conducted for all four dependent variables (safety, privacy, preference, and willingness to spend time in the area). The results showed that all main effects and almost all interaction effects were significant (Appendix B). Next, appropriate post-hoc tests (Appendix C) were performed, which, together with the estimated marginal means (

Table 3. Estimated Marginal Means.

Estimated Marginal Means—Main Effects
		Mean	SE	Mean		SE		Mean		SE	Mean	SE
		Safety		Privacy				Preference			Willingness to Spend Time There
Presence of trees	With trees	3.65	0.05	3.82		0.05		4.05		0.04	4.09	0.04
	Without trees	3.53	0.05	3.59		0.05		3.63		0.05	3.58	0.06
Type of space	Open	3.92	0.05	3.49		0.06		3.91		0.04	3.9	0.05
	Curtains	3.53	0.05	3.77		0.05		3.87		0.05	3.87	0.05
	Corridor	3.32	0.06	3.85		0.05		3.75		0.05	3.73	0.06
Size of space	Large	3.82	0.04	3.57		0.06		3.93		0.04	3.92	0.05
	Mixed	3.59	0.05	3.72		0.05		3.83		0.04	3.82	0.05
	Small	3.36	0.05	3.82		0.05		3.77		0.05	3.76	0.05
Estimated Marginal Means—interactive effects: Type ✻ Size
Type	Size	Mean	SE	Mean		SE		Mean		SE	Mean	SE
		Safety		Privacy				Preference			Willingness to spend time there
Open	Large	4.05	0.05	3.39		0.07		3.91		0.05	3.93	0.05
	Mixed	3.83	0.05	3.56		0.06		3.86		0.05	3.84	0.05
	Small	3.89	0.05	3.53		0.06		3.94		0.05	3.94	0.05
Curtains	Large	3.78	0.05	3.65		0.06		3.97		0.05	3.95	0.05
	Mixed	3.57	0.05	3.75		0.05		3.84		0.05	3.88	0.05
	Small	3.24	0.06	3.9		0.05		3.79		0.06	3.77	0.06
Corridor	Large	3.63	0.05	3.68		0.06		3.9		0.05	3.88	0.05
	Mixed	3.38	0.06	3.84		0.05		3.77		0.05	3.75	0.06
	Small	2.94	0.07	4.03		0.06		3.58		0.07	3.56	0.07
the order of values is in ascending order: a-b-c-d-e-f, the same colour indicating subsequent values that do not differ in a statistically significant way					a	b	c	d	e	f

✻: The standard symbol for interaction between factors.

), helped determine the influence of individual predictors on respondents’ ratings (Figure 7). The mean ratings for the individual scenarios presented in Table 3 were analyzed to assess the significance of the differences between successive mean values for each variable in ascending order. The results of these comparisons were color-coded for illustrative purposes.

The location with trees was rated higher than the area without trees for all the variables. For the remaining factors (size and type of space), clear differences were observed (Figure 7). Open spaces were considered the safest. The addition of lateral (curtain) screens lowered the safety rating, and corridor spaces with longitudinal (corridor) screens were considered the least safe. The respondents conversely assessed the different spatial configurations when it came to privacy. They considered corridor space to be the most private, whereas spaces with lateral (curtain) screens were rated lower, and open spaces were thought to offer the least privacy. While evaluating preference and willingness to spend time in a given area, the respondents did not differentiate between open spaces and areas with lateral (curtain) screens; only corridor space was rated lower.

Differences in ratings also emerged in the interaction effects, which, for size and type of space, were significant for all the variables. Post-hoc tests showed that the safest space was large and open. Respondents also gave high safety ratings to other open spaces (mixed and small) and a large space with screens. Small spaces with screens, especially long spaces (corridor spaces), were rated as the least safe.

The individual scenarios were assessed differently when it came to privacy. A small corridor space (with longitudinal screens) was considered the most private. Small spaces with lateral (curtain) screens and mixed corridor spaces were also rated highly. In general, open spaces were considered the least private, especially large spaces.

The ratings for preferences and willingness to spend time in the area indicated that the impact of the tested factors was clearly less than that on privacy and safety. Apart from the small corridor space, which was rated the lowest, the differences between subsequent evaluations of other types of spaces turned out to be statistically insignificant (Table 3).

4. Discussion

In the Discussion section, we addressed the results of testing hypotheses H1 and H2. The key results are shown in Figure 8. Detailed differences in the ratings are shown schematically in Figure 9.

4.1. Hypothesis H1

This analysis confirmed the first hypothesis. First, it turned out that both privacy and sense of danger influenced our choice of park space for spending time in. This finding corresponds to previous studies [25,32,34,39,40] indicating the need to consider both of these factors in park design. In turn, mediation analysis confirmed that our subjective assessment of the attractiveness of a particular space (preference) explains why we want to spend time in a space that offers privacy and/or safety. Existing studies have confirmed the positive influence of privacy and safety on individual preferences [39,40]. The relationship between preferences and the willingness to spend time in a given space aligns with current knowledge [29,30]. However, there is currently no evidence to suggest that the perception of safety and privacy inherently encourages the use of a space due to their attractiveness as safe and private environments. Nevertheless, it is worth noting that preference explains the impact of both predictors on our willingness to spend time in an area to different extents. In the case of safety, the mediation is absolute; when we control for preference in the model, the relationship between safety and willingness to spend time in the park space disappears. This means that safety affects our willingness to stay in a park area, because it makes it more appealing. The concept that preference is rooted in our survival instinct, as suggested by theories such as prospect-refuge theory [41] and landscape preference theory [60], implies that three factors—safety (directly related to survival), preference (our inclination towards spaces that facilitate survival), and our willingness to spend time in a given area (our comfort in spaces we prefer)—are intrinsically linked in a cause-effect sequence.

The situation is different for privacy. Here, its relationship with willingness to spend time in a particular space was only partially explained by preference. It turned out that an area that the respondents believed to offer privacy encouraged them to stay because they liked it, but also for other reasons. The literature provides a basis for explaining these reasons. It could have resulted, for example, from a willingness to be alone and unrelated to space [38,44,45]. This, in turn, may mean that we choose a space that gives us a sense of privacy, even if we do not fully like it. Therefore, this relationship might be less obvious and unambiguous.

4.2. Hypothesis H2

Comparisons of respondents’ ratings revealed that of the two types of spaces evaluated (with trees and without trees), the space with trees was rated higher in every respect. It felt safer and more private, scoring higher in terms of preference and willingness to spend time there. This confirms the preference for landscapes with single trees that do not form compact blocks, as discovered in previous studies [15,33,60,85]. However, this finding should be treated with caution because the respondents only compared two types of space, which were different. Therefore, it cannot be ruled out that their assessments were swayed by factors other than the presence of trees.

When comparing the scenarios created by manipulating two factors, namely space configuration (screens) and size, significant variations were revealed between the evaluations of the individual scenarios in terms of safety and privacy. To simplify this somewhat, one may observe that these assessments are distributed inversely—the safest spaces do not offer much privacy, and most private spots are not considered safe. Predictably, space size had a positive effect on the sense of safety and a negative effect on perceived privacy. However, in terms of spatial configuration, open spaces were considered the safest, areas with lateral screens (curtains) were less safe, and spaces with longitudinal (corridor) screens turned out to offer the least safety according to the respondents. The opposite is true for privacy. The distribution of evaluations appears to corroborate previous research findings and aligns with the perspective-building theories upon which the research plan was predicated. The increased safety observed in large open spaces may be attributed to enhanced control [13,44]. This is stronger in an open space, where we are visible from a distance and can see our surroundings clearly at the same time. For safety, this scenario is beneficial in several respects. First, such a situation allows one to spot an attacker early enough to escape the attack (see, among others, Appleton’s prospect-refuge theory [31,41,86]. Second, visual contact with surroundings is conducive to social control and eliciting help in the event of a threat [42,43,56]. At the same time, however, this same control undermines one’s sense of privacy [58,59]. Without the possibility of even partial concealment, we cannot quote Altman’s classic definition of privacy, obtain ‘a selective control of access to the self or to one’s group’ [58]. Our findings, when compared with prior research on the influence of spatial factors on privacy and safety in parks, demonstrate a notable similarity. Although our study did not investigate the identical factors outlined in our research plan, certain parallels are evident. Specifically, areas characterized by a low number and density of plants were identified as safer yet less private, whereas areas with a high density of plants were found to be less secure but offered greater privacy [38,40,87].

The implications concerning the configuration of screens are interesting, especially when we consider interactive effects (Figure 7). In the case of an open space, safety was the highest and the size of the space had a relatively small influence on the evaluations when compared to the space with screens. The lack of screens seems to be a key factor for safety and is more relevant than the size of the interior landscape. This result confirms the results of previous studies showing that view limitations have a strong impact on the sense of safety [25,31,86,88,89]. The smaller importance of the size of the interior landscape is likely because control can be maintained even in a relatively small space. Apparently, some distance from the nearest potential hiding place for an attacker created by the walls of the landscape interior is sufficient to maintain this control. It is important to notice an attacker at a distance that allows time to react.

However, introducing longitudinal (corridor) or lateral (curtain) screens to the interior does not yield such unambiguous findings in the assessment of safety. First, for spaces with screens, the size of the space plays a greater role than for open spaces. The respondents rated large spaces as the safest and small spaces as the least safe. This may be due to the fact that screens provide a significant opportunity for a potential attacker to hide [15] which is more important the closer the hideout (screen) is. The importance of hideouts in reducing the sense of safety has been repeatedly confirmed [25,85,90,91]. Second, variations occurred in the evaluation of spatial configuration (type of screen) depending on whether the space featured trees or not. In a space with trees, the introduction of screens significantly undermined a sense of safety, while in the case of large and mixed spaces, it was no longer relevant whether the screens were lateral (curtain) or longitudinal (corridor). Longitudinal screens reduce safety more than lateral screens only in small spaces. This may be due to the fact that screens combined with trees provide stronger cover than without trees, reducing control and making it easier for an attacker to hide. Trees not only provide direct cover (thick trunks) but also provide additional shade, reducing the visibility of the site, which has been highlighted by research [38,92] This was different for the spaces without trees. The corridor spaces were considered the least safe, regardless of the size of the space. Although the fact that screens reduce safety is obvious, it is worth considering in more detail the fact that corridor screens have a stronger negative impact on safety than curtain screens. The former offers a better overview of the path than the surroundings, while the latter has the opposite effect. Apparently, for respondents, control of the surroundings was more relevant to safety than control of the path, especially in the case of clearings without trees. This phenomenon may be explained by spatial legibility, which is related to safety [65,66]. Some studies have also shown that legibility explains the impact of some spatial features (such as vegetation density or method of illumination) on safety [46,65]. Spatial configurations that provide a wide view of the surrounding landscape provide a better idea of the shape of the space than information regarding the course of the path. This makes such an area more legible, improves orientation, and enables more effective construction of mental maps [61] Another reason may be the existence of potential hiding places where an attacker may hide [50,51] In the case of curtain screens, the risk of an unexpected attack (without time to react) arises only when approaching the screen. In the case of corridor screens, danger exists along the entire length of the screen if it does not run continuously or without gaps.

Regarding privacy, the findings also indicated interactive effects. First, the introduction of screens, in contrast to safety, is more relevant to spaces without trees. Additionally, for spaces with trees, screens are more significant in the case of small spaces and curtains increase privacy to a lesser extent than corridors. Screens have a more pronounced effect on privacy in spaces without trees, although there is no difference in the impact of longitudinal (corridor) and lateral (curtain) screens; privacy is enhanced by any screen. This difference may result from an opposite rationale than in the case of safety: a lack of trees means a lack of any screen that might offer privacy. Therefore, introducing such a screen, regardless of type, dramatically increases the sense of privacy, which is not the case in spaces with trees.

Finally, we can compare the evaluations of preferences and willingness to spend time in park spaces. In both cases, we observe a clear ‘flattening’ of the graph—the differences between the scenarios are much smaller than in the case of safety and privacy. This indicates that preference and choice regarding space are caused by the interaction of different, often opposing feelings [38,46]. However, if we probe deeper, we can note some interesting differences in terms of the interaction effects. First, in the case of spaces with trees, adding screens differentiated the ratings for small spaces only (lower ratings), whereas the spatial configuration did not matter in terms of how large and mixed spaces were evaluated. The situation is different in spaces without trees. Here, the spatial configuration seems to matter. In general, spaces with curtain screens were rated higher in terms of preference than those with corridor screens. Interestingly, large spaces with curtain screens were rated higher than open spaces (without screens). This advantage disappeared in the respondents’ assessment of their willingness to spend time in space, which did not increase after the addition of lateral (curtain) screens. Generally, however, it can be assumed that, apart from small spaces where the screens lower the ratings—in the remaining scenarios, the ratings of preferences and willingness to spend time differ only slightly or not at all. This confirms the complexity of how park spaces affect people’s feelings, that it is ambiguous and dependent on the situation and needs of a particular visitor at a particular moment. The need for safety and privacy, which are key factors influencing preferences and choices, depends on spatial features in different ways. Analysis of these relationships offers deeper insight into how park visitors feel and, therefore, a better opportunity to adapt the space to their needs.

4.3. Limitations

The research method used in this study has certain limitations. First, the number of assessed variables strongly restricted the number of photographs that could be evaluated. Consequently, only two scenarios were rated and manipulated according to the factors to be assessed. To confirm the findings obtained, it is necessary to conduct a similar study with more scenarios (different photos manipulated in a similar way). In particular, it would be important to select a sample of assessed photos that would allow for taking into account the variability resulting from, among others, the morphology of the terrain, the presence of reservoirs and watercourses, the nature of the vegetation, the spatial context, including the surroundings, the time of day and year, the weather, and other factors that significantly influence perception and feelings [93].

This indicates that the research should indeed be replicated, but the results obtained here seem promising.

Secondly, assessments based solely on visual factors limit our understanding of the potential impact of other, non-visual phenomena [94]. This is an inherent limitation of all research based on visual representations of reality, from photos to virtual reality (VR) visualizations. This is because, among other things, (1) participants’ lack of full experience of the environment being assessed, photographs do not capture the dynamic and multi-sensory aspects of the environment [95]; (2) limitations in complex environments, in which photographs may not fully capture [96], and the influence of uncontrolled technical conditions, such as image quality, lighting, and viewing angle, which can lead to distortions in the results [97].

Third, the research is cross-sectional in nature, considering the feelings and preferences of various user groups, but its universality is limited by geographical conditions. The findings were identified in diverse social categories, but they concern a specific region of Central Europe and are embedded within this cultural area. In the future, it would be worthwhile to expand the research to consider cultural and geographical diversity (cross-cultural comparative studies). There are significant cultural differences in preferences for park landscapes, which are influenced by various factors, such as cultural background, historical context, and individual experiences [98] (For example, American participants experienced greater psychological benefits from viewing mountains and forests, while Taiwanese participants experienced greater benefits from viewing water and parks [96,99]).

Fourth, the study included responses from respondents who constituted a representative sample of the Polish population but only examined the influence of two demographic characteristics on the responses: age and gender. Therefore, the study did not consider the differences in responses depending on a number of factors, such as place and environment of residence, social status, and frequency of visiting parks [100]. Further research could be conducted to identify the influences of these and similar factors.

5. Conclusions

The study corroborated the hypothesis that both privacy and a sense of safety significantly influence the attractiveness ratings of park spaces, thereby affecting individuals’ willingness to spend time in these areas.

In addition, by comparing the ratings for individual scenarios, several general conclusions can be drawn that can be applied to park-space design. First, lateral (curtain) screens generally have a more positive effect on the perception of space than longitudinal (corridor) screens. The findings suggest that corridor spaces will probably be more private in certain situations only (in this case, in small and mixed spaces with trees), and corridor spaces tend to be perceived as less safe, which is especially true for small spaces. Furthermore, people were less willing to spend time in small corridor spaces (lower preferences). Second, open spaces (compared to spaces with screens) enhance safety but reduce the sense of privacy. How they are assessed will probably depend on individual needs and preferences, and on which of these two needs is more important to the visitor. This was indicated by the relatively equal average preference and willingness ratings given to open spaces and spaces with screens. Third, of all the types of spaces assessed, small spaces with screens (especially corridors) were the worst, being evaluated on average as less attractive than small spaces without screens. This is because they are significantly less safe. Therefore, despite the fact that such spaces are conducive to privacy, they also scored lower on preference and willingness to spend time there. Furthermore, in general, the findings indicate that the size of the space played a lesser role in the assessments of open spaces than spaces with screens, especially corridors. At the same time, the spatial configuration was most relevant to the evaluation of small spaces (compared to large and mixed spaces).

The primary contribution of this study is to establish and demonstrate the following: The perception of privacy and safety within a space significantly influences individuals’ willingness to utilize it, as these factors affect their subjective attractiveness. Consequently, for park spaces to be visited frequently, they must address both privacy and safety requirements. Private and safe spaces require distinct, often conflicting, spatial modifications related to plant screens. The sense of privacy is maximized in small spaces with screens that limit visibility, whereas the perceived safety is enhanced in large open spaces. Current research has not yet demonstrated the feasibility of creating a space that is both secure and private by using plant screens. Therefore, it is crucial to allow visitors to select a space that aligns with their primary needs under the existing conditions.

Corridor screens are generally rated lower than curtain screens. Therefore, whenever feasible, plant screens should be designed to avoid creating tunnels that restrict lateral views, except when prioritizing the highest possible sense of privacy.

These conclusions, which enhance our understanding of the mechanisms underlying park space perception, may have practical implications for sustainable designs. They facilitate a more socially effective shaping of plant forms, particularly those with significant environmental value, such as dense vegetation that creates visual screens within a space.