Concept of Statistics

Data are exact numerical facts collected systematically and arranged for a particular purpose. Data may be obtained from official sources, government publications, ministry bulletins and international bureau statistics.

1. It enables the geographers to handle large sets of data and summarize them in a way that can be easily understood.
2. It can also enable the geographers to make comparisons between geographical phenomena, e.g. to compare the amount of rainfall and agriculture production or population distribution in different regions, etc.
3. Statistics translates data into mathematical ways, which make the application of Quantitative techniques possible.
4. It enables the geographers to store the information in forms of numbers, graphs, tables, charts, etc.
5. Statistics give precise rather than generalized information. This offers a lot of satisfaction to the user.
6. Statistics is very useful for planning at local and national levels. For example, statistics on census can be used to plan for social services.

There are two sources of geographical data, which include primary sources and secondary sources.

These are the data obtained directly from the field through questionnaires, observation, interviews, tests and focus group discussion.

These are the data obtained from libraries, magazines, newspapers, published or unpublished documents such as books, journals, maps and other public documents.

1. Discrete Data: are data which cannot take any value within a given set but can only represent a whole number like people and animals, cars, house, livestock.
2. Continuous Data: these are data which can take any value within a set of a given number. These values have fractions and decimal points. Continuous data include those data whose values can be measured like temperature, altitude, height, etc.
3. Individual Data: these are data provide precise, specific and exact value for each individual item in a sample given. Every individual represents its own value. For instance in Vituka High School comprises of five streams A, B, C, D, E and each stream has 45, 63, 42, 51, 51 students respectively. Each figure is thus an exact value for a given class.
4. Grouped Data: this represent a group of value or class which may fall under one value or class in with no exact figures are quoted but where several values fall within certain classes or groups.

A variable is anything or characteristic that data may have, or an attribute which changes in value under given conditions. Variables include population size, age, sex, altitude, temperature and time. Variable can be classified into two major forms:

1. An independent variable is a variable factor, which influences the changes of other variables or outcomes eg. Sex, year etc. it is expressed on the x-axis. The independent variable is also known as manipulated variable.
2. A dependent variable is an outcome or result that has been influenced by other variables. A dependent variable does not influence or change other variables. The dependent variable responds to independent variable. It is called dependent because it "depends" on the independent variable.