The study of visitor behaviour is a field of behavioural science defined by its setting rather than the behaviour itself. Thus, it is much more to do with how the built environment works than pure psychology. The purpose of this chapter is to provide some background to the methodology of the case studies introduced later and to establish the contribution and utility of the field to zoo design. The focus is architectural rather than psychological.
The scientific study of human environments--or human ecology--began in the first half of this century  but began to enter the awareness of architects only from about the 1960s. In that period, Modernist architecture entered a crisis with the assumption that architects automatically understand the users of their buildings beginning to be questioned. The test of good architecture came to be how people actually behave in built environments.
The Modern Movement is generally regarded as a reaction against nineteenth century classicism and eclecticism. It enjoys a freedom of expression free from rules and academic traditions. Indeed, a principle goal is the expression of ideas or emotions, not simply expression of purpose . The ‘crisis’, or realisation of its failings, was precipitated by the very conditions which produced the movement: industrialism, population growth, the growth in power of the State over the individual, social dislocation caused by these, plus war and economic hardship. It was thus closely associated with public housing when the need for rapid reconstruction came. This architectural determinism lead to the study of how buildings did indeed modify behaviour. 
The study of visitor behaviour has only emerged very recently as a distinct field, but the types of research it conducts have been undertaken for a great deal longer.  Thus its history parallels that of environmental design research. It is primarily associated with museums. Zoos eschewed such research until relatively recently and tended to rely on their inherent popularity to maintain their visitor numbers. They (along with museums) have also been the last resort for public amusement in hard times.
Today, affluence, rising running costs for zoos and greater choice for leisure activities mean a more studied approach is required to attract visitors. Singapore Zoo itself has commissioned market research in the past. Although visitor studies is still an ill-defined field, certain basic ideas and approaches from the larger, parent field tend to be more useful in zoo-based research than others.
The study of human behaviour in zoos is an extremely narrow field but it has one distinguishing feature which is the effect of animals on visitors. Having established the need for zoos to understand how visitors use them, it is necessary to say research can help. Behavioural studies have two possible objectives :
Generally the first type will study how spaces work through circulation patterns and attractions. How visitors use their environment to orient themselves to it, find their way and come to understand it. A particular concern in museums and zoos is obviously how visitors learn.
To these ends, visitor studies can encompass a vast range of methodologies. Many are suggested by the behaviour they attempt to gauge and the settings in which they take place. Thus, Finlay et al showed pictures of animals in various contexts to subjects to assess their visual perception of a variety of zoo exhibit types and natural settings.  Most studies in zoos do not rely as this did on the zoo nature of the setting, except indirectly, possibly due to the museum background of the majority of researchers. This study just is also an extension of a standard method of assessing scenic qualities using photos or drawings and falls into the category of basic repeatable research. The difficulty with most studies is also that they may be useful only to the subject zoo. There can be dangers in mis-interpreting results as well. 
Martin and O'Reilly characterise studies of behaviour in zoos as mainly visitor-environment or animal-environment; rarely staff-environment; and exceptionally an integration of all three. Zoos are seen as suitable settings for studies of environmental perception and cognition, environmental aesthetics and landscape assessment, crowding and spatial problem solving. They suggest that future research should focus on four areas. These are paraphrased as follows :
Bitgood et al, similarly identify three categories of influences on visitor behaviour as: the animals being exhibited; architectural characteristics; and characteristics of the visitors. The architectural characteristics which they are interested in are: sensory competition (from other exhibits or distractions), proximity to animals, visibility, and exhibit type (moated or barred). Zoos are such complex environments that even with identical species in different enclosures, “it is difficult to attribute visitor reactions to any one factor” .
Thus, while architects and exhibit designers take it on faith that they can influence the outcome of a visitor's experience of animals in zoos, establishing what the link is rather daunting.
This dissertation makes use of a range of techniques to impartially measure visitor behaviour and attitudes towards exhibits. All the methods involved field work, that is, no experimental approach was attempted with organised subjects outside the zoo or in more controlled environments. Thus, there is less control and the data captured reflects real situations rather than simplified laboratory set ups.
Such field studies fall into two categories: invasive and non-invasive. The first involves purposely “invading” visitors' reverie and asking them suitable questions about their experiences. It results in data of the type obtained in opinion polls. The second involves traffic counts, or following visitors surreptitiously and recording their behaviour dispassionately. Video is sometimes used as it allows counting and recording at leisure. Hodometers have also been used to count passing visitors. For this dissertation, visitor groups were monitored in the traditional way by following them. Traffic counts at the entry points to ‘Primate Kingdom’ were also conducted.
The principle approach was, however, the questionnaire. Included in these were sets of semantic differential scales. These allow visitors to distinguish shades of meaning between subjective opposite descriptions by placing a mark along a scale between two semantic opposites. This method contrasts with the phrasing of the questions and answer type surveys. It was endeavoured to keep the language colloquial as it was anticipated that some respondents might not have good verbal skills in English. (A Chinese language survey is discussed later). As mentioned, some early questions are built on later. Thus, criticism that the type of question which goes, ‘Do you like . . . ?’, is leading the respondent to give answers the questioner wants is countered by the neutral request to rate the exhibit from bad to good, or from one neutral descriptor to its opposite in semantic differential scales. In these, it is not obvious what answer the questioner is seeking. Some of scales were selected as dictionary synonyms in order to overcome unforeseen connotations in visitors' minds of particular words. The most significant result, then is the combination of each set of synonymous scales.
Behavioural models. It is well also to understand what the results say about the experience of visitors, that is, how accurate they are and how literally they can be interpreted. Psychologists construct models of human behaviour based on assumptions about how people process and act on information from the environment. For example, people are said to behave according to their internal balance of various states of being, such as intuitive-rational, or cognitive-emotive. The learning process is a combination of affective and cognitive mental processes. Different people are constituted with different balances of these two ways of processing information.
Serrell asserts that people's needs in a zoo are: a sense of control; a sense of discovery; a sense of personal significance; and a sense of personal enrichment.  This ties in with an idea now current, that conservation education serves little purpose if visitors go away with a feeling of powerlessness to do anything about extinction and habitat destruction.
As a disclaimer, the tests conducted for this dissertation are not rigorously based on any one model. They rely simply on the gathering of opinions taken at face value with perhaps the application of some common sense . The point of this discussion is that it is important to remember that the validity of answers to rational questions from intelligent human beings is suspect because rationality is only one characteristic of normal humans.