BSNS102 1

• Quantitative
• Qualitative

Numerical eg. age:measured in years

Grouped/ Categorical eg. Preferred accomodation type (Budget, Tourist, Superior)

• Nominal (name or number given to a category as a label)
• Ordinal (name or number implies ranking)

• Discrete (whole or counting numbers)
• Continuous (infinite number of values eg. Age, Income)

Whole collection of things under consideration

Portion of the poplulation selected for analysis

Summary measure that describes the characteristic of the population

Summary measure computed that describes a characteristic of a sample.

• Primary data
• Secondary data
• Census
• Experimental data
• Surveys

• Coverage error
• Non response error
• Measurement error

Chance differs from sample to sample

• Mean (Average)
• Median (Middle value)
• Mode
• Trimmed Mean (cuts out extreme 5%)

• Range (Max - Min)
• Interquartile range (middle 50%)
• Varience (std dev around the mean)
• Std Deviation (square root of the varience)

• Symmetric distribution (median = mean)
• Right skewed (Tail to the right)
• Left skewed (Tail to the left)

• Positive Kurtosis: Data clusters more and have longer tails
• Negative Kurtosis: Data is less clustered and has shorter/ fatter tails

• Box (shows interquartile range)
• Line (median)
• Whiskers (highest and lowest value)
• Outliers
• Extreme outliers