Representation of Data

This is a quick lesson about representation of data. I thought I publish it since I haven’t posted for a while. These are really just basic facts about representation of data.

There are two types of data, one type is the Qualitative and the other is the Quantitative data. Qualitative data uses words such as favorite cars like BMW while Quantitative data uses numbers such as number of uncles like 4.

To expand on those two types of data we’ve seen above; There are two types of quantitative data, discrete and continuous data. Discrete data can be counted for example number of cars and continuous data is measured for example the height of someone 170cm, which can only be found by carrying out measurements.

Data can be categorized depending on how it has been collected; Primary data us data collected by you while secondary data is data collected by someone else, this is usually data which has been provided to work from from for example in experiments or exams.

The advantages of primary data is that you’re satisfied with the data, you have a good and confident understanding of the data accuracy since you collected it, and you’re very aware of how the data was collected. The disadvantages are data collection can take a very long time and it can also be very expensive.

The advantages of secondary data it is quicker and easier to get the data in large amounts and it’s also cheap since the data is often available. The disadvantages are; You’re not aware of the data accuracy or how the data was collected and it might be out of date.

Ways of collecting data are using questionnaires, counting, measurements, or data logging; Data logging refers to a machine used to record record results at set intervals. You can use books to up data, you can also use magazines, newspapers and the internet.

Choosing Primary or Secondary data

If you decide to use secondary data be sure to get the exact and a better precision of the information that you need. Consider the important factors such as the reliability of the sources and whether the data collector might be biased.

If you’re considering to use primary data then decide whether to use questionnaire, counting or measuring. Consider the level of accuracy of the data and how the data will be recorded.

One common term in representation of data is population. Population refers to all people or objects in subject. When you collect data from a whole population it is called: Census however if you collect from part of the population this is know as a Sample. When collecting a sample from a population it’s important to make sure that the sample represents the population fairly otherwise the sample is referred to as a biased sample

These are some of the common words in representation of data.