Week 3: Data Exploration & Processing in Excel Flashcards
- Understand the steps before data analysis. - Understand how to use Excel for data summarization and exploration. - Learn how to use PivotTables to describe data.
1
Q
Structured data (definition)
A
Data that resides in a fixed field within a file or record
2
Q
Unstructured data (definition)
A
Data that is usually not in a certain
format
3
Q
Essential steps before data analysis
A
Data collection and data cleaning (wrangling)
4
Q
Steps before formal data analysis
A
(1) Get familiar with the dataset, know the data volume, what each row and column
means, and the data format of each row and column.
(2) Data cleaning/data wrangling
5
Q
Data cleaning/data wrangling steps
A
- Check for missing data, Extreme outliers, Erroneous value formats, Impossible values, Inconsistent values, Duplicate records
- Check if data re-organization is needed.
- Check if data transformation is needed.
- Check if textual information needs to be transformed into numbers
6
Q
Extreme outliers (definition)
A
data points that are significantly different from the other observations
7
Q
What PivotTables do
A
Let you quickly summarize your data in almost any way
imaginable to gain important insights
