After They Had Failed in the Writing Exam That Was

question 8

Multiple Choice

After they had failed in the writing exam that was required for all students before graduation,15 students were placed in a class in which they received additional tutoring.After completing this class,all 15 students retook the exam and earned higher scores.Their success was held up as an example that the class curriculum really works.What source of internal invalidity has not been considered?

• A)history effect
• B)noncomparable groups
• C)contamination
• D)regression

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Definitions:

Short-Run Costs

Costs that vary depending on the level of production or output in the short term, where some factors of production are fixed.

Zero Economic Profits

A situation in which a firm's total revenues are exactly equal to its total costs, including opportunity costs, indicating neither an economic profit nor loss.

Long-Run Equilibrium

A market state where all producers and consumers have fully adjusted to all changes, and there are no forces causing further adjustments.

Production Costs

The total expense incurred in manufacturing a product or providing a service, including raw materials, labor, and overheads.