UNIT 2 Flashcards
used to describe basic features of the data in the study and provide simple summaries about the sample and measures
Descriptive Statistics
describe and understand the features of a specific data set and to repurpose hard-to-understand quantitative insights across a large data set
Descriptive Statistics
Two Types of Variables
- Categorical Variables - qualitative, has distinct groups and variables
- Continuous Variables - quantitative, represent measurable amounts
number of times a particular value occurs in the data
Measure of Frequency
can be expressed in ratio, rates, proportions and percentages
Relative Frequencies
single values that attempts to describe a set of data by identifying their central position within hat set of data
Measures of Central Tendency
arithmetic average or the sum of values in a data set divided by the total number of observations
Mean
middle distribution when the data are ranked in order from lowest to highest
Median
most common value in a data set
Mode
describes the degree to which a variable are similar or diverse
Measures of Dispersion
difference between the lowest and the highest value in a set of values
Range
measures of spread that reveal how close each observed value is to the mean of the entire data set
Variance and Standard Deviation
T/F All descriptive statistics are wither measures of central tendency or measures of variability
True
Two Types of Modes
- Bimodal - distribution has two modes
- Multimodal - distribution has more than two modes
another name for the 50th percentile
Median
often used when the distribution of scores is either positively or negatively skewed
Median
used when data are interval or ratio scaled and data are not skewed
Mean
Morse Type. In symmetrical distributions, the median and mean are equal. For normal distributions, mean = median = mode.
Both T
Morse Type. In positively skewed distributions, the mean is smaller than the median. In negatively skewed distributions, the mean is larger than the median.
Both F
also known as measures of dispersion
Measures of Variability
T/F The more spread out a distribution is, the larger the measure of dispersion is.
True
Three common measures of variability
- The range
- Semi-interquartile range (SIR)
- Variance / Standard Deviation
Three common measures of variability
- The range
- Semi-interquartile range (SIR)
- Variance / Standard Deviation
Difference of the first and third quartiles divided by two
The Semi-Interquartile Range
T/F The larger the variance is, the less the scores deviate, on average, away from the mean.
False
degree of asymmetry or irregularity of a distribution
Skewness
Three Types of Kurtosis
- Leptokurtic - highest curve
- Mesokurtic - middle curve
- Platykurtic - lowest curve
