2022 Introduction to Statistics in Research Mitchell 2nd ed

I N T R O T O R E S E A R C H : D A T A V I S U A L I Z A T I O N & C O M M O N S T A T T E S T S

Continuous numerical: Variable that can be any value in a given interval. Usually measurements of something (like height). (Quiz)

Let's compare categorical and numerical variables.

Categorical

Numerical

Qualitative data Quantitative data Usually qualities, characteristics, or categories Usually quantiles, counts, or amounts CATEGORICAL EXAMPLES NUMERICAL EXAMPLES Gender (record male or female) Height (recorded in feet and inches) Blood type (record: A+, A-, B+, B-, AB, O-) Heart rate (recorded in number of beats per minute) Political party (record: Democrat, Republican, Independent) Household income (recorded in USD per year) Hair color (record: brown, black, blonde, red, etc.) Number of textbooks purchased

Table 62: Categorical and Numerical Comparison

Self-Assessment: Name that variable..

Question 1: Colors of cars in a faculty parking lot are what type of variable?

Answer: categorical

Question 2: The number of iPads owned by students at SMWC. What type of variable? (be specific) Answer: Discrete numerical Question 3: The amount of time it takes students to drive to SMWC. What type of variable? (be specific) Answer: Continuous numerical

Descriptive Statistics

Descriptive statistics are used to describe the basic features of data. It helps you learn the story of the data. Make sure to distinguish descriptive statistics from inferential statistics. With inferential statistics, the researchers make inferences from the data to more general conditions.

Once you have data, the first thing you need to do is get a feel for the size of values and try to spot anything unusual.

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