Descriptive Analysis (15) Flashcards
What are the categories?
How common is each category?
Methods: Frequency and Cross-Tabs
What are the central tendencies: means, medians, and modes?
What are the dispersions: standard deviations, variances, and percentiles?
Method : Descriptive Statistics
Descriptive Statistics
This helps you summarize numeric variables:
Mean: Average
Median: Middle value
Mode: Most frequent value
Standard Deviation: How spread out the values are
Use this for data like carat weight or price.
🛠 SPSS Steps:
Analyze -> Descriptive Statistics -> Descriptives
📌 Tip: Use median instead of mean when there are outliers (extremely high or low values) that can skew the results.
Frequencies
Use this to count how often each category appears (like how many diamonds are color “D”, “E”, etc.)
SPSS Steps:
Analyze -> Descriptive Statistics -> Frequencies
Cross Tabulation
Use this when comparing two categorical variables. Example: “Do diamonds with Good Symmetry usually have Very Good Polish?
🛠 SPSS Steps:
Analyze -> Descriptive Statistics -> Crosstabs
Scatter Plot
This shows the relationship between two numeric variables (e.g. Carat vs. Price).
🛠 SPSS Steps:
Graphs -> Scatter/Dot -> Simple Scatter
Select Cases
Use this to isolate specific groups in your data. For example, if you only want to look at natural diamonds, filter your data by Type = ‘GIA’.
🛠 SPSS Steps:
Data -> Select Cases -> If condition is satisfied
When should you use the median instead of the mean?
When your data has outliers or is skewed.
What does cross-tabulation show?
The relationship between two categorical variables.
What do frequencies help identify in your dataset?
How often each category (like color or cut) appears.
What does a scatter plot help you visualize?
The relationship between two numeric variables.
How do you filter data in SPSS to analyze a specific group (e.g., lab-grown diamonds)?
Use “Select Cases” and set a condition like Type = ‘GIA Lab-Grown’.
What are measures of central tendency?
Mean, Median, Mode.
What are measures of dispersion?
Standard Deviation, Range, Interquartile Range.
What is the advantage of using SPSS syntax?
It records your steps, making it easier to replicate or edit analysis.
