unit 2 Flashcards
What is univariate descriptive statistics focused on?
Univariate descriptive statistics focuses on the summarized description and analysis of a single variable.
What is the first step in data analysis, according to the slides?
The first step is to build the dataset.
What does each row and column represent in a dataset, according to the slides?
Each row represents a subject/participant, and each column represents a variable.
What is absolute frequency (fi)?
Absolute frequency (fi) is the number of times a value of a variable is repeated in the dataset.
What is relative frequency (f’i)?
Relative frequency (f’i) is the proportion (over total amount) of the frequency of a certain value with respect to the total sample.
How is percentage (pi) calculated?
Percentage (pi) is calculated by multiplying the relative frequency (f’i) by 100.
What is cumulative absolute frequency (Fi)?
Cumulative absolute frequency (Fi) running total of absolute frequencies for all data up to a certain point in a dataset.
What is cumulative relative frequency (F’i)?
Cumulative relative frequency (F’i) (the running total of relative frequencies (percentages or proportions) for all data up to a certain point in a dataset.) is the cumulative proportion (a fraction or percentage of the total)
How is cumulative percentage (Pi) calculated?
Cumulative percentage (Pi) is calculated by multiplying the cumulative relative frequency (F’i) by 100.
What are the typical components of a frequency distribution table?
Typical components include absolute frequency (fi), relative frequency (f’i), percentage (pi), cumulative absolute frequency (Fi), cumulative relative frequency (F’i), and cumulative percentage (Pi).
What is the purpose of graphical representations in frequency distributions?
Graphical representations facilitate the understanding of the data and their characteristics.
When are cyclograms or pie charts useful?
Cyclograms or pie charts are useful for nominal, ordinal, and discrete quantitative variables with few values.
What do bar charts represent?
Bar charts represent the frequency of each value, with bars along the Y-axis and values along the X-axis.
What is a polygon of frequencies?
A polygon of frequencies uses points representing the absolute frequency of each value, connected by lines, and is useful for comparing groups or describing profiles.
How do histograms differ from bar charts?
Histograms use unseparated bars to represent the continuity of a variable, and are typically used for continuous quantitative variables, sometimes grouped into class intervals.
What is a stem and leaf diagram used for?
A stem and leaf diagram shows the order and shape of the data and is useful for evaluating possible anomalies in the distribution of a variable.
What does a box plot show?
A box plot shows the position indexes, with a central line at the median, and indicates the form of the variable including symmetry and outliers.
What are the four properties that characterize the shape of a frequency distribution?
The four properties are central tendency, variability, skewness, and kurtosis.
What does central tendency indicate?
Central tendency indicates where the distribution is centered and where the data are grouped.
What does variability indicate?
Variability indicates the degree of dispersion or concentration of observations with respect to the mean or other values.
What does skewness measure?
Skewness measures the degree to which the values are evenly distributed above and below the central tendency.
What is a symmetrical distribution?
A symmetrical distribution is one where the mean divides the distribution into two identical halves.
What does kurtosis measure?
Kurtosis measures the degree of concentration of the data with respect to the central values, indicating how flat or peaked the distribution is.
What are measures of position used for?
Measures of position indicate where a score or value is located within the distribution compared to the other observed values.
What are the most common quantiles used?
The most common quantiles are quartiles (4), deciles (10), and percentiles (100).
What is a percentile?
A percentile is a value that leaves below itself a certain percentage ‘K%’ of the sample.
What are measures of central tendency?
Measures of central tendency represent the average magnitude of all observed values of a variable and establish a middle point or point of balance.
What is the mode?
The mode is the value with the greatest frequency in the distribution.
What is the median?
The median is the middle score when all scores are arranged from the lowest to the highest.
What is the mean?
The mean is the average value of the distribution and is calculated by summing all the scores and dividing by the number of scores.
