Geographical Research. Geographic Information Systems

Research is the creation of new knowledge through systematic and organized investigation of critical questions and problems. Geographers in education, business, and government service are frequently called upon to do research.

The research process involves several steps. First, the geographer must identify a research problem, and relevant literature is then reviewed. The geographer may then predict certain relationships among variables. For example. Aristotle predicted that temperatures would increase as latitude decreased. Having made predictions, the geographer obtains and analyzes data in order to examine the validity of the hypotheses. The results of the analyses are used to draw conclusions about the problem.

Hypothesis Testing, Data, and Data Analysis. The process of prediction involves the development of hypotheses. Hypotheses are predictive statements about reality. Aristotle hypothesized that temperature increased as latitude decreased. Someone working with the gravity model might hypothesize that more people will move from New York to Florida than from New York to Wyoming.

Hypotheses state relationships between variables. A variable is a quantity whose value differs over space and time. Latitude, temperature, population density, and income are examples of variables. Variables can be either dependent or independent. A dependent variable is one whose value responds to changes in an independent variable. In the gravity model, migration is the dependent variable while size of place and distance are independent variables. For Aristotle, temperature was the dependent variable and latitude was an independent variable.

Having stated a hypothesis, the geographer proceeds to obtain data in order to examine its validity. Data are pieces of information organized in such a way that hypotheses can be tested. In hypothesis evaluation, geographers make use of either primary data or secondary data. Primary data are data obtained by the researcher directly. Human geographers often obtain primary data through interviews, questionnaires, or field observation.

Secondary data are data collected by others. Huge quantities of data useful in geographical research are collected and published by government agencies, businesses, trade associations, and many other organizations.

Once collected, the data are used to evaluate the hypotheses. Many hypotheses can be evaluated with the use of maps. Hypotheses may also be tested using statistical procedures. Correlation and regression analysis are valuable for this purpose, in part because these procedures are easily visualized (Box 1-3). Indeed, cartographic and statistical procedures generally complement one another, and a geographer will often make extensive use of both in a single research project.

Geographic Information Systems. Today, the mapping and statistical analysis of geographic data are often integrated. A geographic information system (GIS) is a computer software package that simultaneously analyzes and displays geographic information. Geographic information systems are used extensively in many facets of human geography, including transportation planning, energy resource development, population projection, electoral districting, public service provision, natural-resource management, and disaster planning.

A GIS includes three primary components: data storage capability, statistical-analysis capability, and mapping capability (Figure 1-15). Data are arranged in matrix form. Each row of the matrix represents a place and each column represents variables measured in places. The U.S. Census Bureau publishes large quantities of place-specific data. Data on population, migration, race and ethnicity, income, employment, occupational structure, housing, agriculture, industry, services, and many other aspects of American life are included. These data are reported for each state, each county, each incorporated city and town, and small areas known as census tracts within each metropolitan area throughout the country.

Figure 1-15. A Schematic of Geographic Information Systems. Geographic information systems include three basic components: data storage capability, computer graphics, and statistical packages. Together, these capabilities render geographic information systems very powerful research tools

The information included in a GIS permits many different analyses to be undertaken. Not only can each variable be mapped individually, but additional maps that combine two or more variables can be produced quickly and easily. A geographer interested in relationships between income and urban development might wish to identify rapidly growing high-income neighborhoods.

Maps of income and urban growth can be overlaid in order to distinguish high-income neighborhoods that are growing rapidly from others that fail to meet both criteria. Maps can be drawn from the original data set itself, from the results of statistical analyses, or from mathematical operations involving the data.