Data preparation and

data capturing

Topics Covered:

Data preparation

Data capturing

Data verification and validation

Data editing

Data preparation:

Data preparation involves checking or logging the data in, checking the

data for accuracy, entering the data in the computer, transforming the

data and developing and documenting a database structure that

integrates the various measures.

Logging the data:- The data may come from a number of different

sources at different times. A data base may be setup that enables the

user at anytime to know what data is in and what is still needed.

Checking the data for accuracy: As soon as the data is received it is

screened for accuracy in some cases it leads to previous collection to

clarify any problems or errors.

Developing a database structure: The structure in which the user

wants to store the data for the study so that it can be accessed in

subsequent data analysis. Generally the two options can be used for

storing data on computer

•Data base programmes

•Statistical programmes

Entering the data in computer: There are a wide variety of ways to

enter the data into the computer for analysis. The simplest way is to

type the data directly. In order to assure a high level of data accuracy

special programmes can be used that allow checks procedure to reduce

the data entry errors.

Data transformations: Once the data have been entered it is necessary

to transform the raw data into valuables that are usable in the analysis.

Data capturing:

It is a method of actually collecting the data from various resources

which may be manual or in computers data may be captured by using

different types of input devices. Input devices may be online or offline.

Online data entry: It involves devices such as terminals, which are

connected directly to the computer. On line processing is also called as

direct processing. The data may be keyed in directly by the use of

keyboard or other data collection and recording devices. Using these

input data appropriate records may be quickly updated. Also the access

to and retrieval of any record is quick and direct.

Offline data entry: It involves devices through which data is recorded

on some media such as magnetic tapes or magnetic disks and then

entered into computer later. Since data entry is done by data entry

operators and their speed is less than data processing so in most

applications data entry is done offline. This saves computer time. The

major forms of permanent storage are cards, tapes and disks.

There are offline data entry devices for each type.

Key to card: Oldest offline data entry devices. It allows an operator to

convert data recorded on paper to punched cards.

Key to tape: A key to tape device is designed to record keyed data

directly onto magnetic tape.

Key to floppy: These data entry machines were introduced as low cost

data recording systems. They are used to store data directly on flexible

disks, called floppies that are inexpensive and reusable.

Key to disk: Key to disk devices are used as recording stations in

systems where data from different points has to be recorded for

processing at one point.

Data verification and validation: It is a process in which data entered

in computer is checked for correct type and correct value. This

validation procedure can be performed on the individual record or on

group of records. Also the process of data validation can be performed

at different levels of data during output process. The different validation

checks that can be applied in a system are as follows:

Completeness check:- The check ensures that all the fields in the

record are entered in a proper sequence. In a multiple record check

programme verification is performed after a number of specified

records and if any of the error is detected the entire group of records is

rejected

Consistency check:- It refers to the comparison of one type of data

with other if the second one is completely dependent on the first data.

This check ensures that if the same data is available at two places then

data should be completely same at both the places.

Sequence check: This check is used to verify the data which has been

recorded is in a sequence so as to check the correctness of the sequential

order of the data before processing the data. If the key field value of the

records is not in a sequence then the process of sorting is done before

actually processing of the data.

Duplicacy check: This check is used to find out the duplicate records.

Duplicate records are identified and removed to make the data

consistent and to save the time of computer system.

Data editing: It is a process which is performed to represent the data

which is stored in the memory. By representation of data means that the

data should be given to the user after all the processing in such a way

that it contains no unnecessary information.

Some of the editing processes are as follows:

Insertion of decimal point: Data editing can be applied to indicate the

place of decimal point on the screen and the number of digits after the

decimal point.

Currency symbol: It is used to insert the currency symbol before or

after the numeric data. It can be a dollar symbol $ or the sign of rupees.

Data justification: It is used to represent the data in some predefined

justification order. e.g. character data is right aligned. This utility of

data justification is used to align the data in some predefined width of a

cell.

Insertion of comma: Business amounts are generally represented by

separating the digits by commas. By default computer software does not

include in numeric figures but commas can always be inserted under the

process of editing.

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