Brown: Chapter 4 Flashcards
Descriptive stats provide…
an analysis of the data that helps describe, show, or summarize it in a meaningful way such that patterns can emerge
What is inferential statistics?
Inferential statistics are techniques that allow us to use study samples to make generalizations that apply to the population.
Frequencies are used to describe…
How often something occurs.
- Typically, the actual number or count is provided, along with a percentage.
What is a frequency distribution?
A frequency distribution is the count that indicates how often something occurs within a given interval.
What is a frequency table?
A frequency table presents the data in columns and rows so it can be interpreted horizontally and vertically.
- Graphs present information pictorially, allowing the reader to “see” patterns.
What is a histogram?
A histogram is a frequency distribution represented in a bar graph.
- The vertical (y) axis identifies the frequency with which a score occurs.
- The horizontal (x) axis presents the values of the scores.
When is a pie chart appropriate?
A pie chart is only appropriate for representing frequencies when all of the “slices,” or categories, of the pie total 100%.
A measure of central tendency describes…
the location of the center of a distribution
What are the measures of central tendency?
Mean
Median
Mode
What is the mode?
Mode is the value that occurs most frequently in the distribution.
What is the mean?
Mean is the same as the average and balances the scores above and below it.
What is the median?
Median is the score value that divides the distribution into the lower and upper halves of the scores.
What is variability?
Variability is the spread of the data and is another way to compare data sets.
What are the measures of variability?
Range
Standard deviation
What is range?
Range is a measure of variability that indicates the lowest and highest scores.
What is a normal distribution?
In a normal distribution, data points are distributed in a symmetrical, bell-shape curve.
The two halves are mirror images, with the largest frequency occurring at the middle of the distribution, and the smallest occurring at the ends or “tails.”
The mean, median, and mode will all be the same value.
The concept of a perfectly normal distribution is only theoretical; with actual data, it is rare that a distribution will be exactly symmetrical.
What does is mean to be positively skewed?
Mode is a lower score than the mean, and the median falls between the mode and mean; there are more low scores, and the right tail is longer.
What does is mean to be negatively skewed?
Mode is a higher score than the mean, and the median falls between the mode and mean; there are more high scores, and the left tail is longer.
What is bimodal distribution?
Some distributions have more than one peak and are described in relation to the number of peaks.
