Recording and Organisation of Data

The collection, recording, and presentation of data help us to draw inferences from them.

Now the District Football Association recorded the ages (in years) of the football players as well.

The ages (in years) of the players are:
13, 14, 14, 17, 16, 15, 16, 12, 15, 16.

The data in this form is called raw data.

Now, if we arrange the data in ascending or descending order, then we can interpret the data in a better way.

12, 13, 14, 14, 15, 15, 16, 16, 16, 17 (Ascending order)

The data arranged in an ascending or descending order is called an array or arrayed data.

Now, we can easily tell that
 The youngest player in the team is 12 years old
 The oldest player is 17 years old.
The above data can also be arranged in a tabular form

Why do we collect data?

We first collect and record data, then it is presented in a way such that it gives meaningful information. We primarily collect data for  the following reasons, 

1) Analysis
Let us consider an example where we are using data for analysis.
The table given below is the data of the top 5 scorers in the FIFA World Cup 2018.

This data helps us to analyse the performance of the top 5 scorers in the FIFA World Cup 2018.

2) Comparison

Data is also useful for comparison of data sets.

The table given below shows the performance of Indian Cricketers.

From the given table we can easily compare the performances of the cricketers. We can find which cricketer among these three have played maximum matches, whose strike rate is the highest?

3) Prediction

We use data for predictions, like weather forecasting where previous data of weather conditions are compared with the present data to predict future weather.

Collecting Data

The District Football Association has recorded the heights (in cm) of the football players of the district team. The heights of the players  are: 152, 151, 148, 163, 159, 150, 143, 157, 147 and 167.

The above data can tell us many things, like the height of the tallest and the shortest player, but is this data sufficient if we want to find the age of the youngest player in the district football team?

The answer is no because for that we need to collect data regarding the age of all the players. Therefore, before collecting the data, we need to know what we would use it for.