NCERT Solutions for Class 12 Geography Practical Work in Geography II Chapter 1: Data – Its Source and Compilation

Chapter at a glance

Exercise Questions

Question 1 (i)

A number or character which represents measurement is called
(a) Digit (b) Data (c) Number (d) Character

Answer

Data are defined as numbers or characters that represent measurement from the real world.

2. Data

Question 1 (ii)

A single datum is a single measurement from the
(a) Table (b) Frequency (c) Real world (d) Information

Answer

A single datum is a single measurement from the real world.

3. Real world

Question 1 (iii)

In a tally mark grouping by four and crossing fifth is called
(a) Four and Cross Method (b) Tally Marking Method (c) Frequency plotting Method (d) Inclusive Method

Answer

In tally marking, values are grouped by drawing four vertical strokes and crossing them with the fifth (𝍸) — this is called the four and cross method.

1. Four and Cross Method

Question 1 (iv)

An Ogive is a method in which
(a) Simple frequency is measured (b) Cumulative frequency is measured (c) Simple frequency is plotted (d) Cumulative frequency is plotted

Answer

An ogive is a curve obtained by plotting cumulative frequencies (less than or more than) against class limits.

4. Cumulative frequency is plotted

Question 1 (v)

If both ends of a group are taken in frequency grouping, it is called
(a) Exclusive Method (b) Inclusive Method (c) Marking Method (d) Statistical Method

Answer

In the inclusive method, both the lower and upper limits of a class are included in that class (e.g. 0–9, 10–19).

2. Inclusive Method

Question 2 (i)

Differentiate between data and information.

Answer

Data are raw numbers or characters representing measurements from the real world (e.g. daily rainfall figures of a station). Information is the meaningful answer to a query or a fact that we get from processed data (e.g. “July is the rainiest month at this station”). Data are processed (tabulated, classified, analysed) to produce information.

Data are raw numbers or characters representing measurements of the real world; information is the meaningful fact or answer derived by processing data.

Question 2 (ii)

What do you mean by data processing?

Answer

Data processing is the series of operations carried out on raw data to convert it into meaningful information — collection, editing, classification, tabulation, analysis (statistical calculations) and presentation (graphs, diagrams, maps). Raw data are usually voluminous and unorganised; processing makes them understandable and useful.

Data processing is converting raw data into meaningful information through collection, editing, classification, tabulation, statistical analysis and presentation in tables, graphs and maps.

Question 2 (iii)

What is the advantage of foot note in a table?

Answer

A foot-note, placed at the bottom of a table, explains anything in the table that is not self-explanatory — e.g. abbreviations, units, exclusions, special circumstances, changes in definitions or the source of data. It helps readers understand and interpret the data correctly and check its reliability.

A foot-note explains items in a table that are not self-explanatory — abbreviations, units, exclusions, definitions and the source of data — helping readers interpret the data correctly and judge its reliability.

Question 2 (iv)

What do you mean by primary sources of data?

Answer

Primary data are data collected for the first time by an individual or a group of individuals, institution or organisation directly from the field. Primary sources include personal observation, interview (with schedule), questionnaire, and other methods such as measurement of soil and water samples. They are original and specific to the purpose of the investigation.

Primary sources provide data collected for the first time, directly from the field, through personal observation, interviews, questionnaires/schedules and measurements (e.g. soil and water samples).

Question 2 (v)

Enumerate five sources of secondary data.

Answer

1. Government publications – Census of India, National Sample Survey reports, Indian Meteorological Department reports, Statistical Abstracts of states.
2. Semi-government publications – reports of municipal corporations, zila parishads, urban development authorities.
3. International publications – UN agencies (UNESCO, UNDP — Human Development Report, WHO, FAO), World Bank, IMF.
4. Private publications – yearbooks, surveys and research reports by newspapers and private organisations.
5. Newspapers and magazines; electronic media (websites). (Also unpublished sources — records and documents of government offices, municipal corporations.)

Secondary data sources include government publications (Census, NSS reports, IMD reports), semi-government publications (municipal corporation reports), international publications (UN agencies, World Bank, IMF), private publications (yearbooks, surveys), and newspapers, magazines and websites.

Question 3 (i)

Discuss the national and international agencies where from secondary data may be collected.

Answer

National agencies: 1. Census of India (Office of the Registrar General) – population, housing, literacy, occupation, migration data every ten years. 2. National Sample Survey Office (NSSO) – surveys on consumption, employment, health, education. 3. India Meteorological Department (IMD) – weather and climate data. 4. Survey of India – topographical maps. 5. Geological Survey of India, Central Water Commission, Central Ground Water Board, Forest Survey of India. 6. Ministries (Agriculture, Industry, Commerce) and RBI – economic data; Economic Survey, Statistical Abstracts of India and state statistical abstracts. 7. Semi-government bodies – municipal corporations, district rural development agencies, zila parishads.

International agencies: 1. United Nations – Demographic Yearbook, Statistical Yearbook. 2. UNDP – Human Development Report. 3. FAO – Food and Agriculture data (Production Yearbook). 4. WHO – World Health Statistics. 5. UNESCO – education data. 6. World Bank – World Development Report, development indicators. 7. IMF – financial statistics; WTO – trade statistics; UNEP – environmental data.

These provide data in published form (reports, yearbooks) and increasingly online, which can be used for geographical analysis.

National agencies include the Census of India, NSSO, IMD, Survey of India, Geological Survey of India, Central Water Commission, Forest Survey of India, ministries and RBI (Economic Survey, Statistical Abstracts), and semi-government bodies like municipal corporations. International agencies include the UN (Demographic and Statistical Yearbooks), UNDP (Human Development Report), FAO, WHO, UNESCO, World Bank (World Development Report), IMF, WTO and UNEP.

Question 3 (ii)

What is the importance of an index number? Taking an example examine the process of calculating an index number and show the changes.

Answer

Index number is a statistical measure designed to show changes in a variable or a group of related variables with respect to time, geographical location or other characteristics. It shows change relative to a base year whose value is taken as 100.

Importance: 1. Measures relative change over time or space (e.g. prices, production, population). 2. Makes comparison easy by converting values into a common scale. 3. Used in planning and policy — e.g. wholesale and consumer price indices measure inflation; index of industrial production measures growth.

Process (simple index number)

Example (hypothetical rice production of a district, in thousand tonnes; base year 2000):

Changes shown: production rose by 25% by 2005, 50% by 2010, and 87.5% by 2015 compared with 2000.

An index number shows relative change in a variable with respect to a base year taken as 100, making comparison over time or space easy (e.g. price and production indices). Index = (value in given year ÷ value in base year) × 100. E.g. production of 80, 100, 120, 150 (base 2000 = 80) gives indices 100, 125, 150 and 187.5 — increases of 25%, 50% and 87.5%.

Question Activity – 1

In a class of 35 students of Geography, following marks were obtained out of 10 marks in unit test – 1, 0, 2, 3, 4, 5, 6, 7, 2, 3, 4, 0, 2, 5, 8, 4, 5, 3, 6, 3, 2, 7, 6, 5, 4, 3, 7, 8, 9, 7, 9, 4, 5, 4, 3. Represent the data in the form of a group frequency distribution.

Answer

Step 1 – frequency of each mark

Total = 35 ✓

Step 2 – group frequency distribution (inclusive method, class interval 2):

(𝍸 = four strokes crossed by the fifth, representing 5.)

Observation: most students scored between 2 and 5 marks (21 of 35); only 4 students scored 8 or 9.

Group frequency distribution (inclusive, interval 2): 0–1: 3; 2–3: 10; 4–5: 11; 6–7: 7; 8–9: 4; total 35.

Question Activity – 2

Collect the last test result of Geography of your class and represent the marks in the form of a group frequency distribution.

Answer

Procedure: 1. Collect the marks of all students (e.g. out of 50) from the teacher, without names. 2. Find the range (highest – lowest mark) and choose a suitable class interval (e.g. 10 marks, giving about 5–7 classes). 3. Decide the method — exclusive (0–10, 10–20 …; the upper limit is excluded) or inclusive (0–9, 10–19 …). 4. Prepare tally marks for each class using the four and cross method and count the frequencies. 5. Check that the total frequency equals the number of students; add a title and source.

Sample (40 students, marks out of 50, exclusive method)

You may also compute cumulative frequencies and draw a histogram or an ogive.

Collect the class marks, choose a class interval, use the exclusive or inclusive method, tally with the four-and-cross method, and tabulate frequencies so that they total the class strength (e.g. 0–10: 2, 10–20: 6, 20–30: 12, 30–40: 14, 40–50: 6 for 40 students).

Topic checklist

• ☒ Data, information and processing (Q 1 (i), 1 (ii), 2 (i), 2 (ii))
• ☒ Sources of data and agencies (Q 2 (iv), 2 (v), 3 (i))
• ☒ Tabulation, classification, ogive (Q 1 (iii)–(v), 2 (iii), activities)
• ☒ Index numbers (Q 3 (ii))

Total questions answered: 14 of 14