Data Analysis 101: Concepts, Techniques, and Real-world Application

Introduction

Data analysis is the process of collecting, cleaning, organizing,examining and interpreting data to find useful information and play a major role in decision making. As a data analyst, it means looking at numbers and information and trying to figure out what they are telling you

Steps in data analysis

1. Collect data-Whereby this is the collection of data from websites, databases, surveys, websites etc.
2. Clean Data - This is the process of fixing errors, removing duplicates, and handle missing information.
3. Organize Data- Putting information in a useful structure
4. Analyze Data- Use calculations, statistics, and patterns to understand it. 5 Visualize Data- Create charts, graphs and dashboards
5. Interpret and communicate - Explain what the result means and recommend actions.

Tools used in data analysis

• Excel.
• Power BI.
• SQL.

EXCEL

Excel is one of the most beginner friendly tool used in data analysis. We can use excel in the following

• Organize and clean data - where we use things like conditioning formating where the appearance of a cell are changed based on the defined conditions so increasind it's readability
• Calculate totals, averages, percentages and growth - where we come across AVERAGEIFS, SUMIFS ; which only allows to calculate the averages or sums of a particular column if they have met a specific condition
• Filter and sort large datasets - This is where we use the find and replace functions which enables the correction of errors from the wrong type to the required type.
• Create chart and graphs - Creation of charts and graphs depends on the type of visualization you would wish to portray. A good example being the donut chart which we can use to portray six subjects at most in order to enable good readability, other examples include; column and area bar, line graph, clustered and stacked column charts etc.
• Use formulas such as SUM, AVERAGE, IF, COUNTIF, and XLOOKUP- The formulas are used to find the desired result i.e. if you desire your answer to be in total, average or only count the cells that meet a specific requirement. In addition, we also have the VLOOKUP which checks for the desire request in a vertical arrangement and HLOOKUP which looks for the required search in a horizontal arrangement
• Create PivotTables to summarize large amounts of data - In a case of Excel you open a new tab and click on any of the cells plus insert pivotable; Rows are used for grouping categories and columns are used to create comparison layers
• Build reports and dashboards - A report is basically a submission of what your analysis findings and explanations whereas a dashboard is a visualized data in form of tables, a dashboard must have a title, Key performance indicators (KPIs)

Power Quary

Power Quary is an excel inbuilt tool that is used;

• To clean data
• To import data
• To transform data
• To combine data

Power BI.

Power BI helps to turn raw data into interactive reports, charts and dashboards so you can understand what is happening and make decisions. So, we can say power BI is used for visualization.

Dax

Dax analysis expression is a formulae language that power BI uses to create customs and calculations (it can create a calculated measure, column or table)

Categories of Dax functions

• Aggregate/Mathematical/Statistical functions; which include sum, average, maximum, median, and count
• Filter functions - help to modify the filter context
• Logical conditions - evaluate logic in calculations, used to evaluate conditions and return if those conditions and true or false. These logical functions are used in decision making. Examples include ;

1. IF - when you have two or more conditions.
2. Nested IF - when you have more than two conditions.
3. NOT - opposes logic.

• Text functions - where we use the cut and trim
• Date and time functions - where we use functions like; DATEDIF where we can get the difference in time from two different dates 'NOW () which enables us to get the time at the moment, WEEKNUM which enables the counting of the numbers of weeks in an allocated timeframe

Conclusion

Data analysis is an important process that helps individuals and organizations turn data into useful information. Tools such as excel and power BI make data analysis easier by helping users perform calculations, create visualization and present information clearly.Therefore,developing data analysis skills is valuable in today's world because data plays an important role in business,education,research and everyday decions-making.