TEAM 4

Data Cleaning:

        Data cleaning is a process of detecting and correcting corrupted data or inaccurate data from a record set or tables or database. It is mainly used in databases and the term refers to identifying incomplete, incorrect, inaccurate, irrelevant data from parts of the data and then replacing or modifying or deleting the data.

         Data cleaning differs from data validation in that validation almost invariably means data is rejected from the system at entry and is performed at entry time, rather than on batches of data.The actual process of data cleansing may involve removing typographical errors or validating and correcting values against a known list of entities.Data cleansing may also involve activities like, harmonization of data, and standardization of data. For example, harmonization of short codes (St, rd etc.) to actual words (street, road). Standardization of data is a means of changing a reference data set to a new standard, ex, use of standard codes.

        There  are various types of charts how data can be visible clear in charts.

Bar Chart:

      A bar graph is a chart that uses either horizontal or vertical bars to show comparisons among categories. One axis of the chart shows the specific categories being compared, and the other axis represents a discrete value. Some bar graphs present bars clustered in groups of more than one (grouped bar graphs).Bar charts are usually scaled so that all the data can fit on the chart. Bars on the chart may be arranged in any order. Bar charts arranged from highest to lowest incidence are called Pareto charts. Normally, bars showing frequency will be arranged in chronological (time) sequence.

  

                         

Bubble chart:

A bubble chart is a type of chart that displays three dimensions of data.Bubble charts can be considered a variation of the scatter plot, in which the data points are replaced with bubbles.This type of chart can be used instead of a Scatter chart if your data has three data series, each of which contains a set of values.

We have to choose the size of bubbles correctly.