Statistics 1

Question 1

How is measurement defined

Answer 1

the assignment of numerals to objects or events according to rules

Question 2

What is a variable?

Answer 2

A conditon in an experiment or a characteric of an entity, person, or object that can take on different categories, levels, or values and that can be quantified (measured)

Question 3

What’s the Nominal scale?

Answer 3

• assigns names to variables based on a particular attribute
• divides data into discrete categories
• no quantative meaning
  Typical ex.: Gender, marital status etc

Question 4

What’s the Ordinal scale?

Answer 4

• has quantifiable meaning
• reports the ranking and ordering of data
• intervals between values are not assumed to be equal

Example: Likert scales
“Does the instructor show interest..”
never—seldomly—frequently–always

Question 5

What’s the Interval scale?

Answer 5

• Has quantifiable meaning
• Intervals between values are assumed to be equal
• Zero point does not assume the absence of a value
• Values do not originate from zero
• Values cannot be expressed as multiples or fractions

Example: Temperature (Fahrenheit or Celcius)

Question 6

What’s the Ratio scale?

Answer 6

• Has quantifiable meaning
• Intervals between values are assumed to be equal
• Zero point assumes the absence of a value
• Values originate from zero
• Values can be expressed as multiples or fractions
  Typical example: Length

Question 7

Which scales of measurement are parametric?
Which are non-parametric?

Answer 7

Nominal and ordinal data are nonparametric

Interval and ratio data are parametric

Question 8

What’s a difference between DESCRIPTIVE and INFERENTIAL statistics?

Answer 8

Descriptive Statistics
Brief informational coefficients that summarize a given data set
* Measures of central tendency
* Measures variability
* Frequency distribution

Inferential Statistics
Allows you to draw conclusions about your data that can be applied to the wider population
 E.g., t-test or ANOVA

Question 9

What’s more robust to outliers, mean oder median?

Answer 9

Median

Question 10

What is a standard deviation?

Answer 10

• A measure of the variability of a set of data points around the mean
• The standard deviation formula weighs unevenly spread out samples more than evenly spread samples
• The standard deviation is expressed in the same units as the original values

Question 11

What’s the difference between a frequency and a probability distribution?

Answer 11

a Frequency distribution “only” describes the number of observations for each possible value of a variable

and a Probability distribution is an idealized frequency distribution.
it is a mathematical function that describes the probability of different possible values of a variable.