Two Independent Groups If We Do Not Randomly Assign Subjects

question 12

Multiple Choice

Two Independent Groups If we do not randomly assign subjects to treatment conditions,

• A)confounding may occur.
• B)we will gain external validity.
• C)the sample selected may be biased.
• D)we will not be able to estimate effect size.

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Definitions:

Data Distribution

Describes how the values in a data set are spread or distributed.

Proportion of Measurements

The fraction or percentage of measurements falling within a specified range in a dataset.

Frequency Tabulation

A statistical method for organizing data into a table to show how often each different value occurs.

Tchebysheff's Theorem

A statistical theorem that provides a bound on the probability that the value of a random variable deviates from its mean by more than a certain multiple of its standard deviation.