Geography Form 1 Notes : STATISTICS

Statistics

Statistics are numerical figures collected systematically and arranged for a particular purpose.

Statistical data is information presented in the form of numbers, for example:

1. Number of students in a school
2. Mean daily temperature of a place
3. Amount of milk produced daily from a farm
4. Amount of money earned from exports annually

Statistical methods are techniques of collecting, recording, analysing, presenting, and interpreting statistical data.

Significance of Statistics

• Illustrates relationships between two or more varying quantities, e.g., beans production and acreage under cultivation.
• Summarises geographical information, saving time and space.
• Makes comparisons between components, e.g., province with the highest number of people.
• Predicts future trends of weather and climate.
• Predicts natural disasters, e.g., droughts and floods.
• Assists in planning for provision of social amenities, e.g., hospitals and schools.

Types of Statistical Data

Primary Data

First-hand or original information from the field, for example:

• Mean daily temperature from a weather station
• Enumeration/census

Secondary/Derived Data

Second-hand information available in stored sources compiled by other researchers, for example:

• Textbooks
• Reference books
• Maps
• Video/audio tapes
• Newspapers
• Magazines
• Census reports
• Slides

Nature of Statistical Data

Discrete Data

Given in whole numbers, for example:

• 16 elephants
• 1093 tonnes of wheat

Continuous Data

Facts and figures which can take any value, for example:

• Fractions, e.g., 23 ¼
• Decimals, e.g., 6.20 mm
• Values within a range, e.g., 0-30°C

Grouped Data

Non-precise/exact but values range in groups, for example:

Sources of Statistical Data

Primary Sources

People or places which have first-hand or original information.

The information can be collected by observation, measuring, counting, photographing, etc.

Advantages

• Provide first-hand information
• Information cannot be obtained from other sources

Secondary Sources

Materials in which information collected by others was stored, e.g., textbooks, reference books, etc.

Methods of Collecting Data (Statistical Techniques)

Observation

Use of eyes to observe features or weather, then information is recorded immediately, e.g., cloud cover, rocks, soil, landforms, vegetation, etc.

Advantages

• Gives first-hand information which is reliable.
• Relevant material to the study is collected.
• Time-saving since one doesn’t have to look for data in many places.

Disadvantages

1. Data on past activities isn’t available.
2. May be hindered by weather conditions, e.g., mist and dust storms.
3. Ineffective for people with visual disabilities.
4. Tiresome and expensive as it involves a lot of travelling because physical presence is required.

Interviewing

Gathering information from people by direct discussions, then answers are recorded. It may be face to face or on a telephone. A questionnaire prepared in advance is used.

Guidelines

• One should be polite
• Warm and friendly
• Respondents/interviewees should be assured information is confidential.
• Respondent should not be interrupted when answering questions.
• They should not be given clues but answers should come from them.

Advantages

• Reliable first-hand information is collected.
• Interviewer can seek clarification in case of ambiguity of answers.
• Can be used on illiterate respondents.
• Interviewer can gauge the accuracy of responses.

Disadvantages

1. Time-consuming since one person can be handled at a time.
2. Expensive and tiresome as extensive travelling is required to meet the respondents.
3. May encounter language barrier if the respondent doesn’t speak the same language as the interviewer.
4. A respondent may lie, exaggerate, or distort facts leading to collection of wrong information.

Administering Questionnaires

Set of systematically structured questions printed on paper used in interviews or sent to respondents to fill answers.

Types

• Open-ended questionnaire – where the respondent is given a chance to express their views. The disadvantage is that different answers are given which are difficult to analyse.
• Closed-ended (rigid) questionnaire – where respondents are given answers to choose from.

Characteristics of a Good Questionnaire

• Short
• Uses simple language
• Systematically arranged from simple to difficult
• Clear questions
• Doesn’t touch on respondent’s privacy

Advantages

1. Comparisons can be made since questions are similar.
2. First-hand information which is relevant to current trends and situation is collected.
3. Saves money on travelling as physical presence isn’t required.
4. Saves time as all respondents are handled at the same time.
5. A lot of information can be collected.

Disadvantages

1. Difficult analysis due to different answers.
2. Some questionnaires may be sent back blank by lazy respondents.
3. Can’t be used on illiterate respondents.
4. Some respondents may write wrong information.

Content Analysis

Technique of collecting data from secondary sources.

This involves reading, watching films, viewing photographs, and listening to get what is relevant.

Advantages

1. Easy to get data if analysed.
2. Cheap as there isn’t extensive travelling.
3. Saves time as all information is in one place.
4. Possible to get old data.

Disadvantages

1. Difficult to verify accuracy of data.
2. Data may be irrelevant to current trends.
3. Up-to-date data may not be readily available.

Measuring

Determining distances, areas, height, or depth using instruments and recording.

Distance can be estimated by pacing or taking steps of equal and unknown length.

Collecting Samples

Getting a small part, e.g., of soil, rock, or vegetation to represent the whole to be used to carry out tests in the laboratory.

Counting/Census Taking

Arithmetical counting and recording.

Photographing

Capturing on film or video and still photographs.

Digging

Using tools such as hoe, pickaxe, spade, or soil auger to get samples of soil and rocks.

Feeling and Touching

Using fingers to feel the surfaces of soils and rocks to get their textures.

Sampling

Examining by taking a sample – a part representing the whole (population).

Types of Sampling

Random Sampling

Selection of members of a group haphazardly where every item has an equal chance of being selected, e.g., to select 5 students to go for a tour from a class:

• Class members write their names on pieces of paper
• They are folded and put in a basket
• The basket is shaken and five papers are taken out

Systematic Sampling

Selection of members of a sample from an evenly distributed phenomenon at regular intervals, e.g., after every 10 items/members.

Stratified Sampling

Selection of members of a sample by breaking the population into homogenous groups, e.g., to select 6 students to go for a tour:

• Break the class into boys and girls
• Select 3 students from each group by random or systematic sampling
• Combine units from each group to form the required sample

Cluster Sampling

Selection of sample by dividing the sample into clusters with similar characteristics, then a sample is taken from each cluster and representative choices from each cluster are combined to form a sample, e.g., to sample the housing cost, an estate is chosen to represent each group and representative choices are chosen from each estate and combined to form a sample.

Advantages

1. Less expensive
2. Saves time
3. Avoids bias

Disadvantages

1. A poorly selected sample can lead to misleading information
2. Systematic sampling is suitable only for an evenly distributed population

Experimentation

Conducting a test or investigation to provide evidence for or against a theory, e.g., to determine the chemical composition of rocks and soils.

Advantages

1. First-hand data is obtained
2. Gives accurate results if properly conducted
3. Can lead to further discoveries

Disadvantages

1. May be expensive as it involves use of expensive equipment
2. May be time-consuming
3. Use of defective instruments may lead to inaccurate results
4. Improper handling of equipment and chemicals may lead to accidents

Methods of Recording Data

Methods of storing information to avoid losing it.

Note Taking

Writing in a notebook what is being observed, answers during interviews, and then notes are compiled in school or office when writing a report.

Filling In Questionnaires

Filling answers in questionnaires which are responses from a respondent by an interviewer or respondent themselves who then sends it back.

Tallying

Making 4 vertical or slanting strokes and the 5th across the 4 to record data obtained by counting or measuring similar items.

Tabulation

Drawing of tables and filling in data systematically, e.g., weather recording sheets.

Field Sketching

Summarising information observed in the field by making a rough drawing of landscape and labelling the essential information.

Mapping/Drawing Maps

Drawing a rough map of an area of study and labelling in words or symbols accompanied by a key.

Tape Recording

Recording images of an object or landscape on film which is processed to get a photograph, then the photographs are labelled to avoid mix-up during storage.

Labelling Samples

Recording conversations during interviews on audio tapes using a tape recorder.

Permission should be obtained from the respondent to record his/her responses.

Advantages

• Used if responses are too many to be recorded on a notebook.
• Allows smooth flow of discussion as asking respondents to repeat answers would irritate them.

Analysis of Data

Examining the numerical figures in detail.

Techniques of Analysing Data

Calculation of Percentages

If in the study of a farm 10 hectares are devoted to coffee, what is the % of the area under coffee?

10/100 × 10%

The table below shows the number of tourists who visited Kenya from various parts of the world in 2006.

• Calculate the percentage increase of tourists from Africa between 2005 and 2006.

Measures of Central Tendency

Outstanding general characteristics of the data.

Arithmetic Mean

The average

Advantages

• Easy to calculate for a small data set
• Summarises data using a single digit
• Easy to understand and interpret

Disadvantages

• Difficult to calculate for grouped data
• Affected by extreme values

Median

The middle value in a set of data arranged in order.

M = (N + 1) / 2

• 20, 50, 90, 100, 150, 180, 200, 220, 240, 300, 360
• 20, 50, 90, 100, 150, 180, 200, 220, 240, 300

Advantages

• Easy to calculate in a small data set
• Easy to understand as it’s the value in the middle

Disadvantages

• Difficult to calculate in a large data set
• Doesn’t show data distribution

Calculation of Ranges

Difference between the largest and smallest values. Calculate the range for the data above.

Mode

Most frequently recurring value in a set of data.

10, 2, 5, 9, 10, 11, 20, 15, 18, 10

The mode is 10.

Advantages

• Easy to find as no calculation is involved
• Easy to understand

Disadvantages

• Rarely used as a measure of central tendency

Statistical Presentation of Data