Necessity of collecting Data
Think about this situation
The Headmaster of a school (see Fig. 5.2) wanted to open Saving Bank accounts for his students. For this, he needed data from his students. Students did not understand the meaning of the word ‘data’. Do you know what it means? Data means, "facts or figures from which conclusions can be drawn". Data is collected, measured and analyzed, whereupon it can be visualized using graphs or images. In this case, the details could consist of information like the ration card number with address, the name of the student, Aadhaar card identity number, date of birth, phone number for communication etc., These are preserved for drawing inferences.
In our daily life, we come across many situations where we need to collect information in the form of Facts or Numbers.
● Number of students in your class using calculators.
● Number of brothers and sisters in your family.
● Number of different types of houses in a village.
● Number of girls wearing bangles.
● Number of buses crossing a certain road junction at a particular time.
● Number of persons in a street who watch T.V. for more than 2 hours a day.
● Number of shops in a shopping mall selling textiles.
● Speeds of bikes, cars and other vehicles passed along a specific highway.
Thus, the numerical information or facts collected are known as Data.
DO YOU KNOW?
The word ‘data’ was first used in 1640’s.In 1946, the word ‘data’ also meant for “transmittable and storable computer information”. In 1954, a termcalled‘dataprocessing’ was introduced. The plural form of ‘datum’ is ‘data’. It also means “given” or “to give” in Latin.
2. Collection of data
Santhi collected the following information about her friend's preference of sweets which is as shown below.
This way of collecting the data helps Santhi to decide, what sweets to get for her birthday and how much for each.
Collect the data of the birth months of your classmates.
● Tabulate different kinds of crops cultivated by the farmers in a village
● List out different kinds of plants/ trees in your school campus
3. Types of Data
On the basis of collection, data are of two types. They are primary data and secondary data.
Primary data means the raw data (not tailored data) which has just been collected from the original source and has not gone any kind of statistical treatment like sorting and tabulation.
* List of absentees in the class.
* A survey on writing habits of students conducted by a pen manufacturing company.
* The types of leaves collected by students for studying nature.
Collect data on the level of literacy of people in your street.
Secondary data consists of second hand information which has already been collected. It could have been collected by someone other than the user, for some other purpose.
* The Headmaster collects the students’ absentee list from school office.
* Cricket scores gathered from a website.
* Data from Television and Newspapers.
* List of contact numbers from telephone directory.
Primary data is collected in person and so more reliable than Secondary data.