Chapter Two Flashcards
What is a Raw Score?
A Raw Score is a data point that has not yet been transformed or analyzed.
What is a Frequency Distribution?
A Frequency Distribution describes the pattern of a set of numbers by displaying a count or proportion for each possible value of a variable.
What is a Frequency Table?
A Frequency Table is a visual depiction of data that shows how often each value occurred, that is, how many scores were at each value.
Values are listed in one column, and the numbers of individuals with scores at that value are listed in the second column.
What is the functionality of a Frequency Table?
A frequency table shows the pattern of the data by indicating how many participants had each possible score.
The data in a frequency table can be graphed in a frequency histogram or a frequency polygon.
What is a Grouped Frequency Table?
A Grouped Frequency Table is a visual depiction of data that reports frequencies within a given interval rather than the frequencies for a specific value.
What are the Five Steps to Generate a Standard Group Frequency Table?
Step 1: Find the highest and lowest scores in the frequency distribution.
Step 2: Get the full range of data.
Step 3: Determine the number of intervals and the best interval size.
Step 4: Figure out the number that will be the bottom of the lowest interval.
Step 5: Finish the table by listing the intervals from highest to lowest and then counting the numbers of scores in each.
How can the data in a frequency table be displayed?
The data in a frequency table can be viewed in graph form. In a histogram, bars are used to depict frequencies at each score or interval. In a frequency polygon, a dot is placed above each score or interval to indicate the frequency, and the dots are connected.
What is a Histogram?
A Histogram is a graph that looks like a bar graph but depicts just one variable, usually based on scale data, with the values of the variable on the x-axis and the frequencies on the y-axis.
What is a Frequency Polygon?
A Frequency Polygon is a line graph, with the x-axis representing values (or midpoints of intervals) and the y-axis representing frequencies; a dot is placed at the frequency for each value (or midpoint), and the dots are connected.
What is the first step in organizing data for a single variable?
The first steps in organizing data for a single variable are to list all the values in order of magnitude and then count how many times each value occurs.
What are four techniques for organizing information about a single variable?
There are four techniques for organizing information about a single variable: frequency tables, grouped frequency tables, histograms, and frequency polygons.
What is a Normal Distribution?
A normal distribution is a specific frequency distribution that is a bell-shaped, symmetric, unimodal curve.
What is a Skewed Distribution?
A skewed distribution is a distribution in which one of the tails of the distribution is pulled away from the center.
How does symmetry of a histogram relate to the skew of a distribution.
If a histogram indicates that the data are symmetric and bell shaped, then the data are normally distributed. If the data are not symmetric and the tail extends to the right, the data are positively skewed; if the tail extends to the left, the data are negatively skewed.
Describe a positive skew?
With positively skewed data, the distribution’s tail extends to the right, in a positive direction.
