Answer to Question 1
By assigning participants to groups on the basis of the flip of a coin, numbers drawn from a hat, or a table of random numbers, the chance is increased that characteristics other than the independent variable will be equally distributed across treatment groups.
Answer to Question 2
The rate and expression of childhood symptoms and disorders often vary in relation to demographic and situational factors, such as socioeconomic status (SES) (e.g., the social, economic, and physical environment in which the child lives as reflected in measures such as family income, education, or occupation); parents' marital status; and the child's age, gender, and cultural background, to name but a few. Consequently, these variables must be assessed and controlled in most studies.
Some organisms used as models in genetic research
While numerous subspecies of the jaguar have been recognized, recent research suggests just three. G
In 1891 William Dean Howells championed the poetry of Emily Dickinson: “This poetry is as characteri
Controlled cold compression unit.
With the research technique called brainbow, each neuron is labeled with a different color, ...
Doing Qualitative Research: Designs, Methods, and Techniques