Data Types and Characteristics of Data
Quantitative Data
- Quantitative data is portrayed through numbers, meaning it can have a numerical value (like price) or be measured (like weight, distance, or height).
- Two characteristics of quantitative data:
- Discrete - data that identifies data that can be counted and can only take on a certain number of values.
- Continuous - data that identifies data that can be measured and can use any value.
Qualitative Data
- Qualitative data - data that can be arranged into groups or categories based on its qualities; also known as categorical data.
- Two characteristics of qualitative data:
- Nominal data is information that has no natural order.
- Ordinal data is information that follows a natural order.
Why Data Types Matter
- Qualitative data:
- Categories displayed in a chart are categorical or qualitative.
- Cannot be naturally totaled but often counted.
- Quantitative Data:
- Sums, averages, and numbers shown in data and visuals.
- Mixed with categorical data to provide more meaning to the analysis.
Types of Data Review Activity Questions:
- What are the two highest-level types of data for a field?
- Suppose a survey asks respondents for their level of education. This would be considered qualitative data with what characteristic?
- If you ask people to tell you their favorite TV show, what type of data are you collecting?
- When determining how much product was ordered over time, the quantity ordered is what high-level type of data?
- When data can be measured, which characteristic of data is it?
Introduction to Field Data Types
- Data types are controlled by the table design.
- Data types will have different names based on the system.
- Common field data types:
Text/Alphanumeric Field Data Types
- Used to store any type of letter and/or number within the field.
- Example: 35007-0023 is an alphanumeric value. The dash requires this field to be set as an alphanumeric data type.
Date Data Type
- Dates defined with a date data type can capture a date and/or time.
- Needed to calculate other dates or information from a date (e.g., numbers of days between two days).
- Can be used to pull information such as the month number, week number, or day of the week.
Number Date Types
- Number data type will not allow any text.
- Has a variety of different attributes.
- Each database system or data software will provide a variety of number data types.
Currency Data Type
- The currency field data type is a number.
- Can be a number data type formatted to be displayed as currency with a currency symbol and decimal places, or assigned a currency data type.
- Defining numbers as currency enables the use of currency symbols for a particular geographical area.
Boolean Data Type
- A subset of the number data type commonly used for Yes/No, True/False, and On/Off responses represented by a number that is either 1 or 0.
- Each system will have its own defined way of working with the Boolean data type.
Data Type Conversion
- When a data type isn’t as needed, it will need to be converted to the appropriate data type to meet requirements.
- Examples:
- A field containing a date is not set as the date data type, and you want to calculate various dates.
- A field is displaying a number but is stored as text; to sum or count it, you will convert it to a number.
Field Data Types Review Activity Questions:
- Why are field data types important to the data analyst?
- Which field data type is the most versatile of all?
- What feature controls what type of information is stored in a field?
- Who defines the field-level data type in the source system, and what can an analyst do if it is incorrect for the type of analysis required?
Lab Activity
- Lab types:
- Assisted labs guide you step-by-step through tasks.
- Applied labs set goals with limited guidance.
- Complete lab:
- Submit all items for grading and check each progress box.
- Select “Grade Lab” from the final page.
- Save lab:
- Select the hamburger menu and select “Save.”
- Save up to two labs in progress for up to 7 days.
- Cancel lab without grading:
- Select the hamburger menu and select “End.”
- Assisted Lab 2: Understanding Data Types and Conversion
- Applied Lab 4: Understanding Data Structure and Types and Using Basic Statements