Motor

A machine that converts electrical into mechanical energy. Motors that develop rotational mechanical motion are most common, but linear motors are also used. A rotary motor delivers mechanical power by means of a rotating shaft extending from one or both ends of its enclosure (see illustration). The shaft is attached internally to the rotor. Shaft bearings permit the rotor to turn freely. The rotor is mounted coaxially with the stationary part, or stator, of the motor. The small space between the rotor and stator is called the air gap, even though fluids other than air may fill this gap in certain applications.

Cutaway view of a single-phase induction motor. (Emerson Motor Division)
Cutaway view of a single-phase induction motor. (Emerson Motor Division)

In a motor, practically all of the electromechanical energy conversion takes place in the air gap. Commercial motors employ magnetic fields as the energy link between the electrical input and the mechanical output. The air-gap magnetic field is set up by current-carrying windings located in the rotor or the stator, or by a combination of windings and permanent magnets. The magnetic field exerts forces between the rotor and stator to produce the mechanical shaft torque; at the same time, in accord with Faraday's law, the magnetic field induces voltages in the windings. The voltage induced in the winding connected to the electrical energy source is often called a countervoltage because it is in opposition to the source voltage. By its magnitude and, in the case of alternating-current (ac) motors, its phase angle, the countervoltage controls the flow of current into the motor's electrical terminals and hence the electrical power input. The physical phenomena underlying motor operation are such that the power input is adjusted automatically to meet the requirements of the mechanical load on the shaft. See also Electromagnetic induction; Magnet; Windings in electric machinery.

Both the rotor and stator have a cylindrical core of ferromagnetic material, usually steel. The parts of the core that are subjected to alternating magnetic flux are built up of thin steel laminations that are electrically insulated from each other to impede the flow of eddy currents, which would otherwise greatly reduce motor efficiency. The windings consist of coils of insulated copper or aluminum wire or, in some cases, heavy, rigid insulated conductors. The coils may be placed around pole pieces, called salient poles, projecting into the air gap from one of the cores, or they may be embedded in radial slots cut into the core surface facing the air gap. In a slotted core, the core material remaining between the slots is in the form of teeth, which should not be confused with magnetic poles. See also Eddy current.

Direct-current (dc) motors usually have salient poles on the stator and slotted rotors. Polyphase ac synchronous motors usually have salient poles on the rotor and slotted stators. Rotors and stators are both slotted in induction motors. Permanent magnets may be inserted into salient pole pieces, or they may be cemented to the core surface to form the salient poles.

The windings and permanent magnets produce magnetic poles on the rotor and stator surfaces facing each other across the air gap. If a motor is to develop torque, the number of rotor poles must equal the number of stator poles, andthis number must be even because the poles on either member must alternate inpolarity (north, south, north, south) circularly around the airgap.

Geography

As the study of the earth's surface, geography is among the most concrete and accessible of all the sciences. Yet the very definition of geographical knowledge has been highly contested throughout the nineteenth and twentieth centuries. Geographers have disagreed over whether theirs is an analytic or a synthetic study, whether it deals primarily with the realm of nature or culture, and the degree to which it should be concerned with spatial relationships. Geography has also contended with a persistent reputation as simply descriptive inventory of the earth's surface, which has exacerbated its relationship with neighboring disciplines.

Institutional and Intellectual Origins

Through most of the nineteenth century geography was a broadly defined and practical field of knowledge utilized by scholars, explorers, bureaucrats, and politicians. Organizations such as the National Geographic Society and the American Geographical Society flourished in the nineteenth century as meeting grounds for men of science and government. The American Geographical Society, chartered in 1851, was devoted to the nation's growth and progress westward, especially the development of a transcontinental rail route. The organization welcomed not just geographers but also leaders in government, business, education, and science who shared their outlook. Through the society these members were exposed to the nation's exploration, surveying, and mapping efforts, primarily in the American West. Similarly, the National Geographic Society was founded in 1888 as a forum of exchange of information for the community of scientists and bureaucrats in Washington, D. C., involved in geological work. The society continued to facilitate geologically oriented research until the Spanish-American War, when it began a vigorous defense of the nation's mission abroad. In both these organizations, geographical knowledge served the state both concretely, through the supply of scientific expertise, and abstractly, in striking a nationalist posture.

Intellectually, American geography reflected a heavy European influence in the nineteenth century. Among the most influential and popular contemporary geographers were transplanted Europeans such as Karl Ritter and Alexander von Humboldt. Both elevated geography from the realm of description to that of science by considering the landscape as a unified entity to be studied as a whole, a process for which geography was uniquely suited in its stress on synthesis. Louis Agassiz, appointed at Harvard in 1848, was trained in the natural sciences and noted for his development of theories of glaciation and landforms. Arnold Guyot, appointed at the College of New Jersey (later Princeton University) in 1854, began to introduce a concept of geography not as a description of the earth's elements but rather as an observed interrelationship between land, oceans, atmosphere, and human life, all of which interacted harmoniously in a grand design. Though geography would gradually shed this teleological cast, Guyot had pushed geography from description to inter-pretation. George Perkins Marsh also explored this relationship in his Man and Nature (1864), though with a thoroughly theological bent. Into this basic framework of the relatively static view of the human and natural world, the work of Charles Darwin introduced the idea of evolution. As a result, geographers began to pay attention to the evolution of landforms over time, which eventually bolstered the study of physical geography.

By the late nineteenth century geography was no longer simply a tool of exploration, data gathering, and mapping. With the era of exploration waning, and with the coincident rise of American universities, geographers began to turn their attention toward reconceptualizing geography as an analytic, scientific body of knowledge. This was a difficult change for geographers, both intellectually and institutionally. Many worried that their field's reputation—as a broad field open to amateur armchair explorers as well as scientific experts—would taint its prospects in the newly professionalized university.

The unquestioned intellectual father of geography at this critical moment of late-century maturation was actually trained not in geography but geology, because doctoral programs in the former had yet to be developed. William Morris Davis was trained at Harvard as a geologist by Nathaniel Southgate Shaler and appointed professor of physical geography there in 1885. For Davis, the claims geographers made for their study as the "mother of all sciences" had to be halted if progress were to be made, for other scientists regarded this claim as the key indicator of geography's incoherence. Thus began a long tension within geography: What makes the field unique and worthy of its independence? How does a study that is essentially synthetic defend itself from the reach of neighboring sciences as diverse as geology, anthropology, and botany?

Together, Shaler and Davis initiated the first course of training in physical geography—the study of the surface features of the earth—and mentored the first generation of trained geographers in the United States. During the 1880s and 1890s Davis advanced an idea that applied Darwinian principles of evolution to the study of the physical landscape. The result was the science of geo-morphology, in which Davis argued that different elements of the environment worked to produce change on the landscape through dynamics such as soil erosion. This concept helped legitimate geography at the university level and in the process gave geographers a tremendous source of pride. At the same time, however, geomorphology reinforced geography's identity as a subfield of geology, thereby hampering its intellectual independence.

In the late 1870s modern geography began to appear as a field of study in American universities, usually found within departments of geology or "geology and geography." Only in 1898 was an independent department of geography established at the University of California. Davis was convinced that geography's weak reputation was in part attributable to organizations such as the American Geographical Society and the National Geographic Society—especially the latter, which became an increasingly popularized and middlebrow organization after the turn of the century. These groups were irritating to Davis because they reinforced in the mind of the academic and lay communities alike the sense that geography was the pastime of leisured travelers and curious amateurs. He actively dissociated himself from these organizations at the turn of the century, and at one point even attempted to take control of the National Geographic Society in order to return it to its serious, scientific roots. Thus Davis was enthusiastic about a new organization designed exclusively for professional geographers. The Association of American Geographers was founded in 1904, toward the end of the trend toward disciplinary organizations. While geologists were initially welcomed in order to solidify the new organization's membership base, within a few years their applications were deferred in the hope that disciplinary purity might be achieved.

The Advent of Human Geography

Davis was successful in training a number of young geographers at the turn of the century who began to return to the relationship between humans and their physical environment. More specifically, this generation found itself increasingly compelled to study the human response to the physical environment. This turn toward the "causal relationship" was in part a result of the imperative to strengthen geography's position among the disciplines. This new focus had the added benefit of distinguishing geography from geology. Physiography, which linked elements of the environment with one another, and ontography, which linked the environment with its human inhabitants, were the two main areas of disciplinary focus for geography just after the turn of the century. Most early geographers conceived of their discipline as having unique power to bridge the natural and human sciences. From the mid-1890s to World War I the prospect of uniting nature and culture through geography seemed both feasible and imminent at some of the most important centers of academic geography, including Pennsylvania, Chicago, Yale, and Harvard. But it was precisely this claim to breadth that neighboring sciences began to challenge, for in the new era of university science, disciplines were legitimated not by claims of breadth and inclusiveness but rather by narrowing their focus and delimiting their boundaries.

Because of their interest in the causal relationship, theories that united the realm of humans and their environment held special appeal for geographers. For instance, natural selection, though widely misinterpreted, was used to describe the relationship between the physical and the human environments as one of inorganic control and organic response. Evolutionary concepts became central to geography's effort to explain nature's influence upon human behavior, and geography focused increasingly on the question of why certain races, societies, or groups flourished while others languished. To be sure, geographers neglected the idea of random variation and exaggerated and accelerated the process of "struggle" in order to incorporate humans into the ecological world. Yet without this causal connection—the influence of environment on human behavior—the areas of study under geography could easily be divided up among other disciplines.

Even more important than Darwin's ideas were those of Jean-Baptiste de Monet de Lamarck, who suggested that characteristics acquired through the course of a lifetime could be passed biologically to off spring. Lamarck's ideas were well suited to the needs of the new social sciences at the turn of the century because they united the study of nature and humans by linking biology with environment. Though the rediscovery of Mendel's laws concerning genetic heredity in 1900 eroded the credibility of Lamarckian thought, geographers continued to invoke this model when describing the core of their study as the relationship between humans and their natural environment. In other words, Lamarck created for geographers a process to study, and this appeal was too strong to be easily dismissed. Furthermore, Lamarckian constructions meant that geographers were now studying the progress of civilization, which vastly expanded their field of inquiry. By focusing on one's adaptation to the physical environment, the random chance of Darwinian evolution could be replaced with the strength of an individual, a culture, a race, or a nation. These assumptions were not always conceived in deterministic ways. While some geographers invoked them as evidence of an intellectual and social hierarchy in order to justify American expansionism or European imperialism, others used them to open up possibilities for social change. This indeterminacy implicit in Lamarckism allowed it to shape geography long after it had been discredited in other behavioral sciences. In fact it was the range of interpretations possible in Lamarckian expositions that made it so attractive to geographers.

Geography and the State

One of the striking characteristics of geographical thought at the turn of the twentieth century was its implicit support of American expansionism, as demonstrated in the sharp turn that the fledgling National Geographic Society made toward an aggressive defense of America's position abroad during the Spanish-American War. Two Europeans, Halford Mackinder and Friedrich Ratzel, also exercised considerable influence over American geographical thought. Ratzel, trained as a zoologist, argued that a relationship existed between human history and physical geography, in some ways similar to Davis's idea of ontography. But while Davis was relatively tentative in his formulations, Ratzel painted in broad strokes by applying the idea of Darwinian struggle to human society in order to frame the state as an organism that was forced to expand in order to survive. Known by many as the father of geopolitical thought, Ratzel fit well with the contemporary expansionist posture of Josiah Strong, Alfred Thayer Mahan, and Theodore Roosevelt, each of whom was encouraging American expansion into world affairs. Much like the work of Frederick Jackson Turner, Ratzel's ideas allowed geographers to link nature and culture. Ratzel's well-regarded The Sea as a Source of the Greatness of a People (1900) argued that sea power was central to national survival in the twentieth century.

Similarly, Halford Mackinder emphasized environmental influence as a key to the disciplinary identity of the new profession of geographers. His "Geographic Pivot of History" (1904) gave him an extraordinarily solid reputation in the United States; in it he laid out the geopolitical dimension of international politics. For Mackinder, the age of exploration had given way to a new era where the manipulation of information would be critical. In Mackinder's mind the human experience of geography and space had changed in fundamental ways in the late nineteenth century. As Stephen Kern has noted, the rise of geopolitics owed much to the cultural and technological changes taking place around the turn of the twentieth century, including the arrival of standardized time, the advent of flight, the expansion of the railroads, and advances in communication and radio, all of which transformed the everyday experience of space and time. Ratzel and Mackinder used geopolitical ideas in order to come to terms with this changed sense of distance resulting from these innovations. Both emphasized the relationship between geographical influence and human response.

Among the first generation of university-trained geographers who inherited these ideas of Ratzel, Mackinder, and Davis were Ellen Semple, Ellsworth Huntington, and Isaiah Bowman. Semple, a student of Ratzel's, was especially taken with environmentalist models as a way to explain American history. In works such as American Historyand Its Geographic Conditions (1903), Semple argued that living organisms evolve from simple to more complex forms through adaptation to physical environment. The larger the state, race, or people, the more certain its chance of survival relative to others competing for the same resources. Similarly, Huntington posited that the primary influence over human history was climate, and even suggested that these effects could be biologically passed on through generations. Books such as his Civilization and Climate (1915) were tremendously popular with the general public in the early twentieth century, though roundly criticized within geography and other social sciences.

World War I had a substantial impact on American academic geography. Most obviously, the war demonstrated the flexible nature of geographical borders in Europe and the ephemeral nature of colonial associations worldwide. The faith in European civilization was now tempered by its unparalleled capacity for destruction. In the United States, the war demonstrated the utility of geographic knowledge to the public and also advanced the careers of professional geographers called to work for the government. The geographer who benefited most from the war was Isaiah Bowman, then director of the American Geographical Society. One of Bowman's goals had been to make the society more relevant to social and political problems, and by placing its resources at the disposal of the federal government, the society's vast reserve of maps became pivotal to the construction of postwar Europe. The war also led many geographers, especially Bowman, to admit the limits of the environment over human behavior and to stress human influence over the environment. After World War I, geographers devoted tremendous energy to searching for a new relationship to unite the disparate areas under their field, prove its worth in the university, and conform to modern social scientific wisdom, which had deemed environmentalism a false and damaging approach to the study of human affairs.

Geography Since Midcentury

One response to the rejection of environmentalist frameworks as the basis for research was to narrow geography's field of inquiry. The clearest indication of this was Richard Hartshorne's The Nature of Geography (1939), a massive statement of the field's direction written on the eve of World War II. For Hartshorne, what had historically made geography unique was its attention to systematic description of areal variation, not speculation about change over time or causal relationships between humans and their environment. The hope among earlier generations to discover laws of human behavior was dismissed by Hartshorne in favor of a focus on concrete, discrete studies.

Carl Sauer, one of the century's most influential geographers, rejected Hartshorne's treatise—and the approach of the interwar geographers generally—and characterized this period as "the great retreat" when geographers studiously avoided causal relationships between humans and their environment. Sauer thought this unacceptable: geography now conceded physiography to geology and shied away from the social sciences for fear of repeating past sins of environmental determinism. One of Sauer's alternatives was to emphasize the influence of humans over their environment rather than the reverse. In his wake, many students adopted Sauer's new approach in delving into the particularities of place and paying close attention to the development of landscape. Yet despite Sauer's attempt to discredit environmentalism, many geographers continued to grant the physical environment influence over human behavior during the interwar period, an indication of the fractured nature of the discipline at midcentury. In 1947, Harvard made the decision to dissolve its department of geography, the original locus of academic geography in the United States. In subsequent years, Stanford, Yale, Michigan, and innumerable smaller institutions closed their geography departments. Yet the overall number of geography programs rose sharply in the postwar years, a reflection of the general growth of higher education.

Geographers themselves found renewed energy in the 1950s and 1960s by turning toward quantitative analyses as the basis for a redefinition of geography. The "quantitative revolution" did not constitute a change in goals so much as in method: geographers were still searching for locational patterns, but they began to adopt mathematical models, which in some cases led a return to a more abstract, general orientation and away from the idiographic focus on discrete regions. This school of geography drew heavily from economics. But by the late 1960s the quantitative revolution left many concerned that geography was bereft of any purposive, reformist content. Some argued that the quantitative model of geography essentially operated conservatively, in defense of the status quo, and contained little critical potential. A reaction to this—in part inspired by Thomas Kuhn's Structure of Scientific Revolutions (1962)—brought a resurgence of political concerns to the study of geography, but this time with a radical rather than a conservative thrust.

Postmodern, or radical, geography involves first and foremost a critique of the traditional relationship between notions of space and time. For geographers such as Neil Smith and Edward Soja, for instance, Western culture has been preoccupied since the nineteenth century with a historicist focus, and this has come at the expense of an explicitly spatial orientation. They argue that this temporal bent has obscured our awareness of just how deeply the dynamics of power—especially those created by capitalism—are inscribed in spatial relations. For both Smith and Soja, to remedy this requires a critique of historicism and a turn toward spatial concerns. This goal of a more activist, self-critical form of the discipline has continued from the late 1970s forward to the beginning of the twenty-first century, and has brought special attention to the relationship between power and capitalism in the study of urban space. It has infused geography with both theoretical concerns and concrete purpose. In recent years considerable research has also been undertaken in the field of feminist geography, which explores the way gender relations are reinforced by spatial arrangements of societies. The wide influence of these new, conceptually rich areas of research extends well beyond the disciplinary bounds of geography, which suggests the trend toward a more ambitious and socially relevant scope for the subject.

Community

Community

A community usually refers to a sociological group in a large place or collections of plant or animal organisms sharing an environment. This article focuses on human communities, in which intent, belief, resources, preferences, needs, risks and a number of other conditions may be present and common, affecting the identity of the participants and their degree of adhesion.

The word community comes from the Latin communis, meaning "common, public, shared by all or many."[1] The Latin term "communitatus" from which the English word "community" comes, is comprised of three elements, "Com-" - a Latin prefix meaning with or together, "-Munis-" - ultimately Proto-Indo-European in origin, it has been suggested that it means "the changes or exchanges that link" (Both municipal and monetary take their meaning here), and "-tatus" a Latin suffix suggesting diminutive, small, intimate or local.


Perspectives from various disciplines

Sociology

German sociologist Ferdinand Tönnies presented a concise differentiation between the terms "community" (Gemeinschaft) and "society" (Gesellschaft). In his 1887 work, Gemeinschaft und Gesellschaft, Tönnies argued that "community" is perceived to be a tighter and more cohesive social entity within the context of the larger society, due to the presence of a "unity of will."[2] He added that family and kinship were the perfect expressions of community, but that other shared characteristics, such as place or belief, could also result in gemeinschaft.


Individual and community

During human growth and maturation, people encounter sets of other individuals and experiences. Infants encounter first their immediate family, then extended family, and then local community (such as school and work). They thus develop individual and group identity through associations that connect them to life-long community experiences.

As people grow, they learn about and form perceptions of social structures. During this progression, they form personal and cultural values, a world view and attitudes toward the larger society. Gaining an understanding of group dynamics and how to "fit in" is part of socialization. Individuals develop interpersonal relationships and begin to make choices about whom to associate with and under what circumstances.

During adolescence and adulthood, the individual tends to develop a more sophisticated identity, often taking on a role as a leader or follower in groups. If an individual develops the feeling that they belong to a group, and they must help the group they are part of, then they develop a sense of community.


Social capital

If the sense of community exists, both freedom and security exist as well. The community then takes on a life of its own, as people become free enough to share and secure enough to get along. The sense of connectedness and formation of social networks comprise what has become known as social capital.[4]

Social capital is defined by Robert D. Putnam as "the collective value of all social networks (who people know) and the inclinations that arise from these networks to do things for each other (norms of reciprocity)." Social capital in action can be seen in groups of varying formality, including neighbors keeping an eye on each others' homes. However, as Putnam notes in Bowling Alone: The Collapse and Revival of American Community (2000), social capital has been falling in the United States. Putnam found that over the past 25 years, attendance at club meetings has fallen 58 percent, family dinners are down 33 percent, and having friends visit has fallen 45 percent.[5]

Western cultures are thus said to be losing the spirit of community that once were found in institutions including churches and community centers. Sociologist Ray Oldenburg states in The Great Good Place that people need three places: 1) The home, 2) the workplace, and, 3) the community hangout or gathering place.[6]

With this philosophy in mind, many grassroots efforts such as The Project for Public Spaces are being started to create this "Third Place" in communities. They are taking form in independent bookstores, coffeehouses, local pubs and through many innovative means to create the social capital needed to foster the sense and spirit of community.

Psychology

Sense of community

Continuity of the connections between leaders, between leaders and followers, and among followers is vital to the strength of a community. Members individually hold the collective personality of the whole. With sustained connections and continued conversations, participants in communities develop emotional bonds, intellectual pathways, enhanced linguistic abilities, and even a higher capacity for critical thinking and problem-solving. It could be argued that successive and sustained contact with other people might help to remove some of the tension of isolation, due to alienation, thus opening creative avenues that would have otherwise remained impassable.

Conversely, sustained involvement in tight communities may tend to increase tension in some people. However, in many cases, it is easy enough to distance oneself from the "hive" temporarily to ease this stress. Psychological maturity and effective communication skills are thought to be a function of this ability. In nearly every context, individual and collective behaviours are required to find a balance between inclusion and exclusion; for the individual, a matter of choice; for the group, a matter of charter. The sum of the creative energy (often referred to as "synergy") and the strength of the mechanisms that maintain this balance is manifest as an observable and resilient sense of community.

McMillan and Chavis (1986) identify four elements of "sense of community": 1) membership, 2) influence, 3) integration and fulfillment of needs, and 4) shared emotional connection. They give the following example of the interplay between these factors:

Someone puts an announcement on the dormitory bulletin board about the formation of an intramural dormitory basketball team. People attend the organizational meeting as strangers out of their individual needs (integration and fulfillment of needs). The team is bound by place of residence (membership boundaries are set) and spends time together in practice (the contact hypothesis). They play a game and win (successful shared valent event). While playing, members exert energy on behalf of the team (personal investment in the group). As the team continues to win, team members become recognized and congratulated (gaining honor and status for being members). Someone suggests that they all buy matching shirts and shoes (common symbols) and they do so (influence).[8]

A Sense of Community Index (SCI) has been developed by Chavis and colleagues and revised and adapted by others. Although originally designed to assess sense of community in neighborhoods, the index has been adapted for use in schools, the workplace and a variety of types of communities.


Anthropology

Community and its features are central to anthropological research. Some of the ways community is addressed in anthropology include the following:

* Cultural (or Social) anthropological studies of community
* Cross-cultural differences in community
* Ethnographic fieldwork
* Archaeological studies of the community phenomenon in ancient settings
* Anthropology of religion
* Anthropology of education
* Urban anthropology
* Ethnic and Racial Studies
* Community empowerment
* Virtual Internet communities (part of Cyber anthropology)
* Ecological anthropology
* Psychological anthropology


Social philosophy

Communitarianism

Communitarianism as a group of related but distinct philosophies (or ideologies) began in the late 20th century, opposing classical liberalism and capitalism while advocating phenomena such as civil society. Not necessarily hostile to social liberalism, communitarianism rather has a different emphasis, shifting the focus of interest toward communities and societies and away from the individual. The question of priority, whether for the individual or community, must be determined in dealing with pressing ethical questions about a variety of social issues, such as health care, abortion, multiculturalism, and hate speech.

Business and communications

Organizational communication

Effective communication practices in group and organizational settings are important to the formation and maintenance of communities. How ideas and values are communicated within communities are important to the induction of new members, the formulation of agendas, the selection of leaders and many other aspects. Organizational communication is the study of how people communicate within an organizational context and the influences and interactions within organizational structures. Group members depend on the flow of communication to establish their own identity within these structures and learn to function in the group setting. Although organizational communication, as a field of study, is usually geared toward companies and business groups, these may also be seen as communities. The principles of organizational communication can also be applied to other types of communities.


Interdisciplinary perspectives

Socialization

The process of learning to adopt the behavior patterns of the community is called socialization. The most fertile time of socialization is usually the early stages of life, during which individuals develop the skills and knowledge and learn the roles necessary to function within their culture and social environment.[3] For some psychologists, especially those in the psychodynamic tradition, the most important period of socialization is between the ages of 1 and 10. But socialization also includes adults moving into a significantly different environment, where they must learn a new set of behaviors.[10]

Socialization is influenced primarily by the family, through which children first learn community norms. Other important influences include school, peer groups, mass media, the workplace and government. The degree to which the norms of a particular society or community are adopted determines one's willingness to engage with others. The norms of tolerance, reciprocity and trust are important "habits of the heart," as de Tocqueville put it, in an individual's involvement in community.


Community development

Community development, often linked with Community Work or Community Planning, is often formally conducted by non-government organisations(NGOs), universities or government agencies to improve the social well-being of local, regional and, sometimes, national communities. Less formal efforts, called community building or community organizing, seek to empower individuals and groups of people by providing them with the skills they need to effect change in their own communities[12]. These skills often assist in building political power through the formation of large social groups working for a common agenda. Community development practitioners must understand both how to work with individuals and how to affect communities' positions within the context of larger social institutions.

Formal programs conducted by universities are often used to build a knowledge base to drive curricula in sociology and community studies. The General Social Survey from the National Opinion Research Center at the University of Chicago and the Saguaro Seminar at the John F. Kennedy School of Government at Harvard University are examples of national community development in the United States. In The United Kingdom, Oxford University has led in providing extensive research in the field through its Community Development Journal,[13] used worldwide by sociologists and community development practitioners.

At the intersection between community development and community building are a number of programs and organizations with community development tools. One example of this is the program of the Asset Based Community Development Institute of Northwestern University. The institute makes available downloadable tools[14] to assess community assets and make connections between non-profit groups and other organizations that can help in community building. The Institute focuses on helping communities develop by "mobilizing neighborhood assets" — building from the inside out rather than the outside in.


Community building and organizing

M. Scott Peck is of the view that the almost accidental sense of community which exists at times of crisis, for example in New York City after the September 11, 2001 attacks, can be consciously built. Peck believes that the process of "conscious community building" is a process of building a shared story, and consensual decision making, built upon respect for all individuals and inclusivity of difference. He is of the belief that this process goes through four stages:

1. Pseudo-community: Where participants are "nice with each other", playing-safe, and presenting what they feel is the most favourable sides of their personalities.
2. Chaos: When people move beyond the inauthenticity of pseudo-community and feel safe enough to present their "shadow" selves. This stage places great demands upon the facilitator for greater leadership and organisation, but Peck believes that "organisations are not communities", and this pressure should be resisted.
3. Emptiness: This stage moves beyond the attempts to fix, heal and convert of the chaos stage, when all people become capable of acknowledging their own woundedness and brokenness, common to us all as human beings. Out of this emptiness comes
4. True community: the process of deep respect and true listening for the needs of the other people in this community. This stage Peck believes can only be described as "glory" and reflects a deep yearning in every human soul for compassionate understanding from one's fellows.

More recently Scott Peck has remarked that building a sense of community is easy. It is maintaining this sense of community that is difficult in the modern world.

Community building can use a wide variety of practices, ranging from simple events such as potlucks and small book clubs to larger–scale efforts such as mass festivals and construction projects that involve local participants rather than outside contractors.

Community currencies

Some communities have developed their own "Local Exchange Trading Systems" (LETS)[16] and local currencies, such as the Ithaca Hours system,[17] to encourage economic growth and an enhanced sense of community. Community Currencies have recently proven valuable in meeting the needs of people living in various South American nations, particularly Argentina, that recently suffered as a result of the collapse of the Argentinian national currency

Community building that is geared toward activism is usually termed "community organizing." In these cases, organized community groups seek accountability from elected officials and increased direct representation within decision-making bodies. Where good-faith negotiations fail, these constituency-led organizations seek to pressure the decision-makers through a variety of means, including picketing, boycotting, sit-ins, petitioning, and electoral politics. The ARISE Detroit! coalition and the Toronto Public Space Committee are examples of activist networks committed to shielding local communities from government and corporate domination and inordinate influence.

Community organizing is sometimes focused on more than just resolving specific issues. Organizing often means building a widely accessible power structure, often with the end goal of distributing power equally throughout the community. Community organizers generally seek to build groups that are open and democratic in governance. Such groups facilitate and encourage consensus decision-making with a focus on the general health of the community rather than a specific interest group.

The three basic types of community organizing are grassroots organizing, coalition building, and faith-based community organizing (also called "institution-based community organizing," "broad-based community organizing" or "congregation-based community organizing")

Community service is usually performed in connection with a nonprofit organization, but it may also be undertaken under the auspices of government, one or more businesses, or by individuals. It is typically unpaid and voluntary. However, it can be part of alternative sentencing approaches in a justice system and it can be required by educational institutions.


Types of community

From this discussion it is generally recognised that there are three types of different usage of the word community

1. Geographic communities: range from the local neighbourhood, suburb, village, town or city, region, nation or even the planet as a whole. These refer to communities of location.
2. Communities of culture: range from the local clique, sub-culture, ethnic group, multicultural or pluralistic civilisation, or the global community cultures of today. They may be included as communities of need or identity, such as disabled persons, or frail aged people.
3. Community organisations: range from informal family or kinship networks, to more formal incorporated associations, political decision making structures, economic enterprises, or professional associations at a small, national or international scale.

Communities are nested; one community can contain another - for example a geographic community may contain a number of ethnic communities.

Location

Possibly the most common usage of the word "community" indicates a large group living in close proximity. Examples of local community include:

* A municipality is an administrative local area generally composed of a clearly defined territory and commonly referring to a town or village. Although large cities are also municipalities, they are often thought of as a collection of communities, due to their diversity.
* A neighborhood is a geographically localized community, often within a larger city or suburb.
* A planned community is one that was designed from scratch and grew up more or less following the plan. Several of the world's capital cities are planned cities, notably Washington, D.C., in the United States, Canberra in Australia, and Brasília in Brazil. It was also common during the European colonization of the Americas to build according to a plan either on fresh ground or on the ruins of earlier Amerindian cities.

For more details on this topic, see Community of place.


Identity

For more details on this topic, see Community of interest.

In some contexts, "community" indicates a group of people with a common identity other than location. Members often interact regularly. Common examples in everyday usage include:

* A "professional community" is a group of people with the same or related occupations. Some of those members may join a professional society, making a more defined and formalized group. These are also sometimes known as communities of practice.
* A virtual community is a group of people primarily or initially communicating or interacting with each other by means of information technologies, typically over the Internet, rather than in person. These may be either communities of interest, practice or communion. (See below.) Research interest is evolving in the motivations for contributing to online communities.


Overlaps

For more details on this topic, see Intentional community.

Some communities share both location and other attributes. Members choose to live near each other because of one or more common interests.

* A retirement community is designated and at least usually designed for retirees and seniors –- often restricted to those over a certain age, such as 55. It differs from a retirement home, which is a single building or small complex, by having a number of autonomous households.

* An intentional community is a deliberate residential community with a much higher degree of social interaction than other communities. The members of an intentional community typically hold a common social, political or spiritual vision and share responsibilities and resources. Intentional communities include Amish villages, ashrams, cohousing, communes, ecovillages, housing cooperatives, kibbutzim, and land trusts.

Alternative education

Alternative education, also known as non-traditional education or educational alternative, is a broad term which may be used to refer to all forms of education outside of traditional education (for all age groups and levels of education). This may include both forms of education designed for students with special needs (ranging from teenage pregnancy to intellectual disability) and forms of education designed for a general audience which employ alternative educational philosophies and/or methods.

Alternatives of the latter type are often the result of education reform and are rooted in various philosophies that are commonly fundamentally different from those of traditional compulsory education. While some have strong political, scholarly, or philosophical orientations, others are more informal associations of teachers and students dissatisfied with certain aspects of traditional education. These alternatives, which include charter schools, alternative schools, independent schools, and home-based learning vary widely, but often emphasize the value of small class size, close relationships between students and teachers, and a sense of community.

In certain places, especially in the United States, the term alternative may largely refer to forms of education catering to "at risk" students, as it is, for example, in this definition drafted by the Massachusetts Department of Education

Education system

Schooling occurs when society or a group or an individual sets up a curriculum to educate people, usually the young. Schooling can become systematic and thorough. Sometimes education systems can be used to promote doctrines or ideals as well as knowledge, and this can lead to abuse of the system.

Life-long or adult education have become widespread in many countries. However, education is still seen by many as something aimed at children, and adult education is often branded as adult learning or lifelong learning.

Adult education takes on many forms, from formal class-based learning to self-directed learning. Lending libraries provide inexpensive informal access to books and other self-instructional materials. Many adults have also taken advantage of the rise in computer ownership and internet access to further their informal education.

Methodists

The early Methodists reacted against perceived apathy in the Church of England, became open-air preachers and established Methodist societies wherever they went. They were notorious for their enthusiastic sermons and often accused of fanaticism. In those days, members of the established church feared that new doctrines promulgated by the Methodists, such as the necessity to salvation of a New Birth, of Justification by Faith, and of the constant and sustained action of the Holy Spirit upon the believer's soul, would produce ill effects upon weak minds. Theophilus Evans, an early critic of the movement, even wrote that it was "the natural Tendency of their Behaviour, in Voice and Gesture and horrid Expressions, to make People mad." In one of his prints, William Hogarth likewise attacked Methodists as "enthusiasts" full of "Credulity, Superstition and Fanaticism." But the Methodists resisted the many attacks against their movement. (See John Wesley and George Whitefield for a much more complete discussion of early Methodism.)