Understanding Regression Analysis and Variable Relationships
Relationship Between Variables and Regression: The term “regression” was introduced by Galton in his 1889 book Natural Inheritance, referring to the universal law of regression: each peculiarity in a person is shared by their descendants, but on average, to a lesser degree (regression to the mean). His work focused on describing the physical traits of descendants (a variable) based on their parents (another variable).
Pearson (Galton’s friend) conducted a study of over 1,000 households, examining
Read MoreTest Validity and Reliability
True or False
V The validity coefficient cannot be higher than the index of reliability.
V The validity coefficient is affected by the reliability of the criterion.
F The standard error of estimate is the difference between obtained and predicted scores.
F The coefficient of validity is an indicator of the stability of scores.
F The validity coefficient of a test is independent of the homogeneity of the sample.
F The validity coefficient expresses the correlation between two parallel forms of a test.
V
Read MoreT-Tests, ANOVA, and Correlation in Statistical Analysis
T-Tests
Understanding T-Distributions
True Statement: The larger the sample size, the more a t distribution resembles a normal curve.
Estimating Population Variance
When estimating the variance of a population from a sample, the sample variance cannot be used directly because it tends to be slightly too small—it underestimates the population variance.
T-Test vs. Z-Test
The difference between a t test for a single sample and a Z test for a single sample lies in how the variance of the known population
Read MoreBasic Concepts of Sociology and Davis-Moore’s Theory of Stratification
Basic Concepts (p. 34-36)
A basic element of science is the concept, a mental construct that represents some part of the world in a simplified form. Sociologists use concepts to label aspects of social life. A variable is a concept whose value changes from case to case. (“Height”, for example, has a value that varies from person to person).
The use of variables depends on measurement, a procedure for determining the value of a variable in a specific case. Some variables are easy to measure, as when
Read MoreBasic Concepts of Sociology and Davis-Moore’s Theory of Stratification
Basic Concepts (p. 34-36)
A basic element of science is the concept, a mental construct that represents some part of the world in a simplified form. Sociologists use concepts to label aspects of social life. A variable is a concept whose value changes from case to case. (“Height”, for example, has a value that varies from person to person). The use of variables depends on measurement, a procedure for determining the value of a variable in a specific case. Some variables are easy to measure, as when
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