Quantitative Descriptive Statistics Flashcards
The practice or science of collecting and analyzing numerical data in large quantities. It summarizes data from a sample.
Statistics
It provides a standardized method and procedure for summarizing and organizing all cases of one quantitative variable.
Descriptive Statistics
Numbers that summarize data for an entire population.
Parameters
It is the most commonly used descriptive statistic and it is defined as the number of times a particular value of a variable occurs.
Frequencies
The two fundamental types of numerical data.
Quantitative data and Categorical data
It is obtained when the variable being studied is measured along a scale that indicates how much of the variable is present. It is also reported in terms of scores.
Quantitative data
Indicates the total number of objects, individuals, or events a researcher finds in a particular category. Some examples are race, sex, and age group.
Categorical data
It is a theoretical distribution that is symmetrical and in which a large proportion of the scores are concentrated in the middle.
Normal distribution
Described as an asymmetrical type of curve. It is also the degree to which the distribution of data is bunched to one side or the other.
Skewness
Shows a distribution in which there are hardly any scores on the right side of the distribution.
Positively Skewed Curve
There are very few low scores — the long tail
pointing to the left indicates this.
Negatively Skewed Curve
A table that helps researchers create a visual representation of the distribution. This is done by listing the scores in order, from highest to lowest, with tallies to indicate the number of times each score occurs.
Frequency distribution
What are the ways to measure quantitative data?
Number of cases, Measures of central tendency, and Measures of dispersion
The number of cases for which data are reported is represented by the letter _____.
N
__________ is used to collect data from large populations and generalize the statistics to the broader population in an externally valid way.
Sampling
True or False: A normal distribution exhibits zero skewness.
True
True or False: In a distribution that contains an uneven number of scores, the MEAN is the middlemost score (provided that the scores are listed in order).
False
True or False: You can use Z-Scores ad T-Scores anytime even if the distribution is not normal enough to make the conversion to percentages or probabilities become legitimate.
False
True or false: T-scores are the simplest form of standard scores.
False
The primary summary form of data.
Measures of Central Tendency
_____ is the most common measure of central tendency. It is determined by
adding up all of the scores and then dividing this sum by the total number of
scores.
Mean
True or false: “Cognitive Research” seeks to determine whether a relationship exists between two quantitative variables.
False
In a distribution that contains an uneven number of scores, the ______ is the middlemost score (provided that the scores are listed in order).
Median
The ______ is the score that appears most often in a dataset.
Mode
It indicates the spread of the scores in a distribution. This information helps us see how dispersed the responses are to items on an instrument.
Measures of Dispersion
The difference between the highest and the lowest scores to items on an instrument.
Range
________________ is the most useful index of variability. It is a single number that represents the spread of a distribution.
Standard Deviation
A percent stated in decimal form and refers to the likelihood of an event occurring.
Probability
These scores are particularly helpful in
comparing an individual’s relative position on different instruments.
Standard scores
The two standard scores that are most frequently used in educational research are _________ and __________.
z scores and T scores
True or False: When the distribution of scores is normal, both T scores and z scores can be
interpreted in terms of percentile ranks because there is a direct relationship between the two.
True
True or False: It should be remembered that only when the distribution is normal that
the conversion to percentages or probabilities become legitimate.
True
It seeks to determine whether a relationship exists between two quantitative variables. Doing so can be helpful to researchers in
prediction and to identify causation.
Correlation
It uses the symbol r, equivalent to the degree of relationship between two sets of scores/variables.
Correlation Coefficients
_____ is used when a scatterplot shows a nonlinear (curvilinear) relationship.
Eta
True or False: Pearson Product-Moment Coefficient is the most frequently used
correlation coefficients, symbolized as Pearson r.
True
Also known as “cross tabulation”, it is used when the data can be divided between categorical variables.
Cross-break Tables
_________ summarize quantitative data and information in graphs, charts, or pictures that show the relation among scores or variables.
Figures
True or False: Scatterplots and Line Graphs show relationships and interactions between two variables.
True
________ and ________ are constructed by default as an output and visual presentation of the frequencies of data. They are used to depict trends and distributions of data.
Bar Graphs and Pie Charts
